Phosphorus is a
chemical element
A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...
with the
symbol
A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different conc ...
P and
atomic number
The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (''n''p) or the number of protons found in the nucleus of every ...
15. Elemental phosphorus exists in two major forms,
white phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus.
White phosphorus
White ...
and
red phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus.
White phosphorus
White ...
, but because it is highly
reactive
Reactive may refer to:
*Generally, capable of having a reaction (disambiguation)
*An adjective abbreviation denoting a bowling ball coverstock made of reactive resin
*Reactivity (chemistry)
*Reactive mind
*Reactive programming
See also
*Reactanc ...
, phosphorus is never found as a free element on Earth. It has a concentration in the Earth's crust of about one gram per kilogram (compare copper at about 0.06 grams). In minerals, phosphorus generally occurs as phosphate.
Elemental phosphorus was first isolated as white phosphorus in 1669. White phosphorus emits a faint glow when exposed to
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
– hence the name, taken from Greek mythology, meaning 'light-bearer' (Latin ), referring to the "
Morning Star", the planet
Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...
. The term ''
phosphorescence
Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluo ...
'', meaning glow after illumination, derives from this property of phosphorus, although the word has since been used for a different physical process that produces a glow. The glow of phosphorus is caused by
oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
of the white (but not red) phosphorus — a process now called
chemiluminescence
Chemiluminescence (also chemoluminescence) is the emission of light (luminescence) as the result of a chemical reaction. There may also be limited emission of heat. Given reactants A and B, with an excited intermediate ◊,
: + -> lozenge -> ...
. Together with nitrogen, arsenic, antimony, and bismuth, phosphorus is classified as a
pnictogen
A pnictogen ( or ; from grc, πνῑ́γω "to choke" and -gen, "generator") is any of the chemical elements in group 15 of the periodic table. Group 15 is also known as the nitrogen group or nitrogen family. Group 15 consists of the el ...
.
Phosphorus is an element essential to sustaining
life
Life is a quality that distinguishes matter that has biological processes, such as signaling and self-sustaining processes, from that which does not, and is defined by the capacity for growth, reaction to stimuli, metabolism, energ ...
largely through
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phospho ...
s, compounds containing the phosphate ion, PO
43−. Phosphates are a component of
DNA,
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
,
ATP, and
phospholipid
Phospholipids, are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typ ...
s, complex compounds fundamental to
cells. Elemental phosphorus was first isolated from human
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excretion, excreted from the body through the urethra.
Cel ...
, and
bone ash
Bone ash is a white material produced by the calcination of bones. Typical bone ash consists of about 55.82% calcium oxide, 42.39% phosphorus pentoxide, and 1.79% water. The exact composition of these compounds varies depending upon the type of bon ...
was an important early phosphate source. Phosphate mines contain fossils because phosphate is present in the fossilized deposits of animal remains and excreta. Low phosphate levels are an important limit to growth in some aquatic systems. The vast majority of phosphorus compounds mined are consumed as
fertiliser
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
s. Phosphate is needed to replace the phosphorus that plants remove from the soil, and its annual demand is rising nearly twice as fast as the growth of the human population. Other applications include
organophosphorus compound
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective in ...
s in
detergent
A detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates, which are soap-like compounds that are more ...
s,
pesticide
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...
s, and
nerve agent
Nerve agents, sometimes also called nerve gases, are a class of organic chemicals that disrupt the mechanisms by which nerves transfer messages to organs. The disruption is caused by the blocking of acetylcholinesterase (AChE), an enzyme that ...
s.
Characteristics
Allotropes
Phosphorus has several
allotropes
Allotropy or allotropism () is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements. Allotropes are different structural modifications of an element: th ...
that exhibit strikingly diverse properties.
The two most common allotropes are white phosphorus and red phosphorus.
[Abundance](_blank)
ptable.com
From the perspective of applications and chemical literature, the most important form of elemental phosphorus is
white phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus.
White phosphorus
White ...
, often abbreviated as WP. It is a soft, waxy solid which consists of tetrahedral molecules, in which each atom is bound to the other three atoms by a formal single bond. This tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of when it starts decomposing to molecules. The molecule in the gas phase has a P-P bond length of ''r''
g = 2.1994(3) Å as was determined by
gas electron diffraction.
The nature of bonding in this tetrahedron can be described by
spherical aromaticity In organic chemistry, spherical aromaticity is formally used to describe an unusually stable nature of some spherical compounds such as fullerenes, polyhedral boranes.
In 2000, Andreas Hirsch and coworkers in Erlangen, Germany, formulated a rule to ...
or cluster bonding, that is the electrons are highly
delocalized
In chemistry, delocalized electrons are electrons in a molecule, ion or solid metal that are not associated with a single atom or a covalent bond.IUPAC Gold Boo''delocalization''/ref>
The term delocalization is general and can have slightly dif ...
. This has been illustrated by calculations of the magnetically induced currents, which sum up to 29 nA/T, much more than in the archetypical
aromatic
In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to satur ...
molecule
benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...
(11 nA/T).
White phosphorus exists in two crystalline forms: α (alpha) and β (beta). At room temperature, the α-form is stable. It is more common, has cubic crystal structure and at , it transforms into β-form, which has hexagonal crystal structure. These forms differ in terms of the relative orientations of the constituent P
4 tetrahedra. The β form of white phosphorus contains three slightly different molecules, i.e. 18 different P-P bond lengths between 2.1768(5) and 2.1920(5) Å. The average P-P bond length is 2.183(5) Å.
White phosphorus is the least stable, the most reactive, the most
volatile, the least
dense
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically ...
and the most toxic of the allotropes. White phosphorus gradually changes to red phosphorus. This transformation is accelerated by light and heat, and samples of white phosphorus almost always contain some red phosphorus and accordingly appear yellow. For this reason, white phosphorus that is aged or otherwise impure (e.g., weapons-grade, not lab-grade WP) is also called yellow phosphorus. When exposed to oxygen, white phosphorus glows in the dark with a very faint tinge of green and blue. It is highly
flammable
A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...
and
pyrophoric
A substance is pyrophoric (from grc-gre, πυροφόρος, , 'fire-bearing') if it ignites spontaneously in air at or below (for gases) or within 5 minutes after coming into contact with air (for liquids and solids). Examples are organolith ...
(self-igniting) upon contact with air. Owing to its pyrophoricity, white phosphorus is used as an additive in
napalm
Napalm is an incendiary mixture of a gelling agent and a volatile petrochemical (usually gasoline (petrol) or diesel fuel). The name is a portmanteau of two of the constituents of the original thickening and gelling agents: coprecipitated al ...
. The odour of combustion of this form has a characteristic garlic smell, and samples are commonly coated with white
phosphorus pentoxide
Phosphorus pentoxide is a chemical compound with molecular formula P4 O10 (with its common name derived from its empirical formula, P2O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant and dehydra ...
, which consists of tetrahedra with oxygen inserted between the phosphorus atoms and at their vertices. White phosphorus is insoluble in water but soluble in carbon disulfide.
Thermal decomposition
Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes. The reaction is usually endothermic as heat is req ...
of P
4 at 1100 K gives
diphosphorus
Diphosphorus is an inorganic chemical with the chemical formula . Unlike nitrogen, its lighter pnictogen neighbor which forms a stable N2 molecule with a nitrogen to nitrogen triple bond, phosphorus prefers a tetrahedral form P4 because P-P pi-bo ...
, P
2. This species is not stable as a solid or liquid. The dimeric unit contains a triple bond and is analogous to N
2. It can also be generated as a transient intermediate in solution by thermolysis of organophosphorus precursor reagents. At still higher temperatures, P
2 dissociates into atomic P.
Red phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus.
White phosphorus
White ...
is polymeric in structure. It can be viewed as a derivative of P
4 wherein one P-P bond is broken, and one additional bond is formed with the neighbouring tetrahedron resulting in chains of P
21 molecules linked by
van der Waals forces
In molecular physics, the van der Waals force is a distance-dependent interaction between atoms or molecules. Unlike ionic bond, ionic or covalent bonds, these attractions do not result from a Chemical bond, chemical electronic bond; they are c ...
. Red phosphorus may be formed by heating white phosphorus to or by exposing white phosphorus to sunlight.
Phosphorus after this treatment is
amorphous
In condensed matter physics and materials science, an amorphous solid (or non-crystalline solid, glassy solid) is a solid that lacks the long-range order that is characteristic of a crystal.
Etymology
The term comes from the Greek ''a'' ("wi ...
. Upon further heating, this material crystallises. In this sense, red phosphorus is not an allotrope, but rather an intermediate phase between the white and violet phosphorus, and most of its properties have a range of values. For example, freshly prepared, bright red phosphorus is highly reactive and ignites at about ,
though it is more stable than white phosphorus, which ignites at about .
After prolonged heating or storage, the color darkens (see infobox images); the resulting product is more stable and does not spontaneously ignite in air.
Violet phosphorus is a form of phosphorus that can be produced by day-long annealing of red phosphorus above 550 °C. In 1865,
Hittorf discovered that when phosphorus was recrystallised from molten
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
, a red/purple form is obtained. Therefore, this form is sometimes known as "Hittorf's phosphorus" (or violet or α-metallic phosphorus).
Black phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus.
White phosphorus
White ...
is the least reactive allotrope and the thermodynamically stable form below . It is also known as β-metallic phosphorus and has a structure somewhat resembling that of
graphite
Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...
.
It is obtained by heating white phosphorus under high pressures (about ). It can also be produced at ambient conditions using metal salts, e.g. mercury, as catalysts. In appearance, properties, and structure, it resembles
graphite
Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...
, being black and flaky, a conductor of electricity, and has puckered sheets of linked atoms.
Another form, scarlet phosphorus, is obtained by allowing a solution of white phosphorus in
carbon disulfide
Carbon disulfide (also spelled as carbon disulphide) is a neurotoxic, colorless, volatile liquid with the formula and structure . The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non ...
to evaporate in
sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...
.
Chemiluminescence
![White phosphorus glowing e17](https://upload.wikimedia.org/wikipedia/commons/d/da/White_phosphorus_glowing_e17.png)
When first isolated, it was observed that the green glow emanating from white phosphorus would persist for a time in a stoppered jar, but then cease.
Robert Boyle
Robert Boyle (; 25 January 1627 – 31 December 1691) was an Anglo-Irish natural philosopher, chemist, physicist, alchemist and inventor. Boyle is largely regarded today as the first modern chemist, and therefore one of the founders of ...
in the 1680s ascribed it to "debilitation" of the air. Actually, it is oxygen being consumed. By the 18th century, it was known that in pure oxygen, phosphorus does not glow at all; there is only a range of
partial pressure
In a mixture of gases, each constituent gas has a partial pressure which is the notional pressure of that constituent gas as if it alone occupied the entire volume of the original mixture at the same temperature. The total pressure of an ideal gas ...
s at which it does. Heat can be applied to drive the reaction at higher pressures.
In 1974, the glow was explained by R. J. van Zee and A. U. Khan.
A reaction with oxygen takes place at the surface of the solid (or liquid) phosphorus, forming the short-lived molecules HPO and that both emit visible light. The reaction is slow and only very little of the intermediates are required to produce the luminescence, hence the extended time the glow continues in a stoppered jar.
Since its discovery, ''
phosphor
A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or vi ...
s'' and ''
phosphorescence
Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluo ...
'' were used loosely to describe substances that shine in the dark without burning. Although the term
phosphorescence
Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluo ...
is derived from phosphorus, the reaction that gives phosphorus its glow is properly called
chemiluminescence
Chemiluminescence (also chemoluminescence) is the emission of light (luminescence) as the result of a chemical reaction. There may also be limited emission of heat. Given reactants A and B, with an excited intermediate ◊,
: + -> lozenge -> ...
(glowing due to a cold chemical reaction), not phosphorescence (re-emitting light that previously fell onto a substance and excited it).
Isotopes
There are 23 known
isotopes
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) ...
of phosphorus, ranging from to .
Only is stable and is therefore present at 100% abundance. The half-integer
nuclear spin and high abundance of
31P make
phosphorus-31 NMR spectroscopy a very useful analytical tool in studies of phosphorus-containing samples.
Two
radioactive isotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
s of phosphorus have half-lives suitable for biological scientific experiments. These are:
* , a
beta
Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiod ...
-emitter (1.71 MeV) with a
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...
of 14.3 days, which is used routinely in life-science laboratories, primarily to produce
radiolabel
A radioactive tracer, radiotracer, or radioactive label is a chemical compound in which one or more atoms have been replaced by a radionuclide so by virtue of its radioactive decay it can be used to explore the mechanism of chemical reactions by tr ...
ed DNA and RNA
probes, ''e.g.'' for use in
Northern blot
The northern blot, or RNA blot,Gilbert, S. F. (2000) Developmental Biology, 6th Ed. Sunderland MA, Sinauer Associates. is a technique used in molecular biology research to study gene expression by detection of RNA (or isolated mRNA) in a sample.K ...
s or
Southern blot
A Southern blot is a method used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detecti ...
s.
* , a beta-emitter (0.25 MeV) with a half-life of 25.4 days. It is used in life-science laboratories in applications in which lower energy beta emissions are advantageous such as
DNA sequencing.
The high energy beta particles from penetrate skin and
cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power ...
s and any ingested, inhaled, or absorbed is readily incorporated into bone and
nucleic acid
Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main cl ...
s. For these reasons,
Occupational Safety and Health Administration
The Occupational Safety and Health Administration'' (OSHA ) is a large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agenc ...
in the United States, and similar institutions in other developed countries require personnel working with to wear lab coats, disposable gloves, and safety glasses or goggles to protect the eyes, and avoid working directly over open containers.
Monitoring
Monitoring may refer to:
Science and technology Biology and healthcare
* Monitoring (medicine), the observation of a disease, condition or one or several medical parameters over time
* Baby monitoring
* Biomonitoring, of toxic chemical compounds, ...
personal, clothing, and surface contamination is also required.
Shielding requires special consideration. The high energy of the beta particles gives rise to secondary emission of
X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...
s via
Bremsstrahlung
''Bremsstrahlung'' (), from "to brake" and "radiation"; i.e., "braking radiation" or "deceleration radiation", is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typicall ...
(braking radiation) in dense shielding materials such as lead. Therefore, the radiation must be shielded with low density materials such as acrylic or other plastic, water, or (when transparency is not required), even wood.
Occurrence
Universe
In 2013, astronomers detected phosphorus in
Cassiopeia A
Cassiopeia A (Cas A) () is a supernova remnant (SNR) in the constellation Cassiopeia and the brightest extrasolar radio source in the sky at frequencies above 1 GHz. The supernova occurred approximately away within the Milky Way ...
, which confirmed that this element is produced in
supernova
A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when ...
e as a byproduct of
supernova nucleosynthesis
Supernova nucleosynthesis is the nucleosynthesis of chemical elements in supernova explosions.
In sufficiently massive stars, the nucleosynthesis by fusion of lighter elements into heavier ones occurs during sequential hydrostatic burning processe ...
. The phosphorus-to-
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
ratio in material from the
supernova remnant
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar mat ...
could be up to 100 times higher than in the
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...
in general.
In 2020, astronomers analysed
ALMA
Alma or ALMA may refer to:
Arts and entertainment
* ''Alma'' (film), a 2009 Spanish short animated film
* ''Alma'' (Oswald de Andrade novel), 1922
* ''Alma'' (Le Clézio novel), 2017
* ''Alma'' (play), a 1996 drama by Joshua Sobol about Alma ...
and
ROSINA data from the massive
star-forming region AFGL 5142, to detect phosphorus-bearing molecules and how they are carried in comets to the early Earth.
Crust and organic sources
Phosphorus has a concentration in the Earth's crust of about one gram per kilogram (compare copper at about 0.06 grams). It is not found free in nature, but is widely distributed in many
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...
s, usually as phosphates.
Inorganic
phosphate rock
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxi ...
, which is partially made of
apatite
Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal. The formula of the admixture of the three most common e ...
(a group of minerals being, generally, pentacalcium triorthophosphate fluoride (hydroxide)), is today the chief commercial source of this element. According to the
US Geological Survey (USGS), about 50 percent of the global phosphorus reserves are in the Arab nations.
85% of Earth's known reserves are in
Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...
with smaller deposits in
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
,
Russia
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
,
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
,
Idaho
Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...
,
Tennessee
Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
,
Utah
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
, and elsewhere.
Albright and Wilson
Albright and Wilson was founded in 1856 as a United Kingdom manufacturer of potassium chlorate and white phosphorus for the match industry. For much of its first 100 years of existence, phosphorus-derived chemicals formed the majority of its prod ...
in the UK and their
Niagara Falls
Niagara Falls () is a group of three waterfalls at the southern end of Niagara Gorge, spanning the border between the province of Ontario in Canada and the state of New York in the United States. The largest of the three is Horseshoe Falls, ...
plant, for instance, were using phosphate rock in the 1890s and 1900s from Tennessee, Florida, and the
Îles du Connétable (
guano
Guano (Spanish from qu, wanu) is the accumulated excrement of seabirds or bats. As a manure, guano is a highly effective fertilizer due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. G ...
island sources of phosphate); by 1950, they were using phosphate rock mainly from Tennessee and North Africa.
Organic sources, namely
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excretion, excreted from the body through the urethra.
Cel ...
,
bone ash
Bone ash is a white material produced by the calcination of bones. Typical bone ash consists of about 55.82% calcium oxide, 42.39% phosphorus pentoxide, and 1.79% water. The exact composition of these compounds varies depending upon the type of bon ...
and (in the latter 19th century)
guano
Guano (Spanish from qu, wanu) is the accumulated excrement of seabirds or bats. As a manure, guano is a highly effective fertilizer due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. G ...
, were historically of importance but had only limited commercial success. As urine contains phosphorus, it has fertilising qualities which are still harnessed today in some countries, including
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
, using methods for
reuse of excreta
Reuse of human excreta is the safe, beneficial use of treated human excreta after applying suitable treatment steps and risk management approaches that are customized for the intended reuse application. Beneficial uses of the treated excreta may ...
. To this end, urine can be used as a fertiliser in its pure form or part of being mixed with water in the form of
sewage
Sewage (or domestic sewage, domestic wastewater, municipal wastewater) is a type of wastewater that is produced by a community of people. It is typically transported through a sewer system. Sewage consists of wastewater discharged from residenc ...
or
sewage sludge
Sewage sludge is the residual, semi-solid material that is produced as a by-product during sewage treatment of industrial or municipal wastewater. The term "septage" also refers to sludge from simple wastewater treatment but is connected to si ...
.
Compounds
Phosphorus(V)
![Phosphorus-pentoxide-3D-balls](https://upload.wikimedia.org/wikipedia/commons/2/27/Phosphorus-pentoxide-3D-balls.png)
The most prevalent compounds of phosphorus are derivatives of phosphate (PO
43−), a tetrahedral anion. Phosphate is the conjugate base of phosphoric acid, which is produced on a massive scale for use in fertilisers. Being triprotic, phosphoric acid converts stepwise to three conjugate bases:
:H
3PO
4 + H
2O H
3O
+ + H
2PO
4− ''K''
a1 = 7.25×10
−3
:H
2PO
4− + H
2O H
3O
+ + HPO
42− ''K''
a2 = 6.31×10
−8
:HPO
42− + H
2O H
3O
+ + PO
43− ''K''
a3 = 3.98×10
−13
Phosphate exhibits a tendency to form chains and rings containing P-O-P bonds. Many polyphosphates are known, including
ATP. Polyphosphates arise by dehydration of hydrogen phosphates such as HPO
42− and H
2PO
4−. For example, the industrially important pentasodium triphosphate (also known as
, STPP) is produced industrially on by the megatonne by this
condensation reaction
In organic chemistry, a condensation reaction is a type of chemical reaction in which two molecules are combined to form a single molecule, usually with the loss of a small molecule such as water. If water is lost, the reaction is also known as a ...
:
: 2 Na
2 3">HO)PO3+ Na
2PO2">HO)2PO2→ Na
5 3P-O-P(O)2-O-PO3">3P-O-P(O)2-O-PO3+ 2 H
2O
Phosphorus pentoxide
Phosphorus pentoxide is a chemical compound with molecular formula P4 O10 (with its common name derived from its empirical formula, P2O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant and dehydra ...
(P
4O
10) is the
acid anhydride An acid anhydride is a type of chemical compound derived by the removal of water molecules from an acid.
In organic chemistry, organic acid anhydrides contain the functional group R(CO)O(CO)R'. Organic acid anhydrides often form when one equivalent ...
of phosphoric acid, but several intermediates between the two are known. This waxy white solid reacts vigorously with water.
With metal
cation
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...
s, phosphate forms a variety of salts. These solids are polymeric, featuring P-O-M linkages. When the metal cation has a charge of 2+ or 3+, the salts are generally insoluble, hence they exist as common minerals. Many phosphate salts are derived from hydrogen phosphate (HPO
42−).
PCl5 and
PF5 are common compounds. PF
5 is a colourless gas and the molecules have
trigonal bipyramid
In geometry, the triangular bipyramid (or dipyramid) is a type of hexahedron, being the first in the infinite set of face-transitive bipyramids. It is the dual of the triangular prism with 6 isosceles triangle faces.
As the name suggests, i ...
al geometry. PCl
5 is a colourless solid which has an ionic formulation of PCl
4+ PCl
6−, but adopts the
trigonal bipyramid
In geometry, the triangular bipyramid (or dipyramid) is a type of hexahedron, being the first in the infinite set of face-transitive bipyramids. It is the dual of the triangular prism with 6 isosceles triangle faces.
As the name suggests, i ...
al geometry when molten or in the vapour phase.
PBr5 is an unstable solid formulated as PBr
4+Br
−and
PI5 is not known.
The pentachloride and pentafluoride are
Lewis acid
A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...
s. With fluoride, PF
5 forms PF
6−, an
anion
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...
that is
isoelectronic
Isoelectronicity is a phenomenon observed when two or more molecules have the same structure (positions and connectivities among atoms) and the same electronic configurations, but differ by what specific elements are at certain locations in the ...
with SF
6. The most important oxyhalide is
phosphorus oxychloride
Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula . It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from pho ...
, (POCl
3), which is approximately tetrahedral.
Before extensive computer calculations were feasible, it was thought that bonding in phosphorus(V) compounds involved ''d'' orbitals. Computer modeling of
molecular orbital theory
In chemistry, molecular orbital theory (MO theory or MOT) is a method for describing the electronic structure of molecules using quantum mechanics. It was proposed early in the 20th century.
In molecular orbital theory, electrons in a molecule ...
indicates that this bonding involves only s- and p-orbitals.
Phosphorus(III)
All four symmetrical trihalides are well known: gaseous
PF3, the yellowish liquids
PCl3 and
PBr3, and the solid
PI3. These materials are moisture sensitive, hydrolysing to give
phosphorous acid
Phosphorous acid (or phosphonic acid (singular)) is the compound described by the formula H3PO3. This acid is diprotic (readily ionizes two protons), not triprotic as might be suggested by this formula. Phosphorous acid is an intermediate in th ...
. The trichloride, a common reagent, is produced by chlorination of white phosphorus:
:P
4 + 6 Cl
2 → 4 PCl
3
The trifluoride is produced from the trichloride by halide exchange. PF
3 is toxic because it binds to
haemoglobin
Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyte ...
.
Phosphorus(III) oxide
Phosphorus trioxide is the chemical compound with the molecular formula P4O6. Although the molecular formula suggests the name tetraphosphorus hexaoxide, the name phosphorus trioxide preceded the knowledge of the compound's molecular structure, a ...
, P
4O
6 (also called tetraphosphorus hexoxide) is the anhydride of P(OH)
3, the minor tautomer of phosphorous acid. The structure of P
4O
6 is like that of P
4O
10 without the terminal oxide groups.
Phosphorus(I) and phosphorus(II)
![YoshifujiR2P2](https://upload.wikimedia.org/wikipedia/commons/1/1a/YoshifujiR2P2.png)
These compounds generally feature P–P bonds.
[Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. .] Examples include catenated derivatives of phosphine and organophosphines. Compounds containing P=P double bonds have also been observed, although they are rare.
Phosphides and phosphines
Phosphide
In chemistry, a phosphide is a compound containing the ion or its equivalent. Many different phosphides are known, with widely differing structures. Most commonly encountered on the binary phosphides, i.e. those materials consisting only of phos ...
s arise by reaction of metals with red phosphorus. The alkali metals (group 1) and alkaline earth metals can form ionic compounds containing the
phosphide
In chemistry, a phosphide is a compound containing the ion or its equivalent. Many different phosphides are known, with widely differing structures. Most commonly encountered on the binary phosphides, i.e. those materials consisting only of phos ...
ion, P
3−. These compounds react with water to form
phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
. Other
phosphide
In chemistry, a phosphide is a compound containing the ion or its equivalent. Many different phosphides are known, with widely differing structures. Most commonly encountered on the binary phosphides, i.e. those materials consisting only of phos ...
s, for example Na
3P
7, are known for these reactive metals. With the transition metals as well as the monophosphides there are metal-rich phosphides, which are generally hard refractory compounds with a metallic lustre, and phosphorus-rich phosphides which are less stable and include semiconductors.
Schreibersite
Schreibersite is generally a rare iron nickel phosphide mineral, , though common in iron-nickel meteorites. It has been found on Disko Island in Greenland and Illinois.
Another name used for the mineral is rhabdite. It forms tetragonal crystals w ...
is a naturally occurring metal-rich phosphide found in meteorites. The structures of the metal-rich and phosphorus-rich phosphides can be complex.
Phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
(PH
3) and its organic derivatives (PR
3) are structural analogues of ammonia (NH
3), but the bond angles at phosphorus are closer to 90° for phosphine and its organic derivatives. It is an ill-smelling, toxic compound. Phosphorus has an oxidation number of −3 in phosphine. Phosphine is produced by hydrolysis of
calcium phosphide
Calcium phosphide (CP) is the inorganic compound with the formula Ca3P2. It is one of several phosphides of calcium, being described as the salt-like material composed of Ca2+ and P3−. Other, more exotic calcium phosphides have the formula CaP, ...
, Ca
3P
2. Unlike ammonia, phosphine is oxidised by air. Phosphine is also far less basic than ammonia. Other phosphines are known which contain chains of up to nine phosphorus atoms and have the formula P
''n''H
''n''+2.
The highly flammable gas
diphosphine
Diphosphane, or diphosphine, is an inorganic compound with the chemical formula P2H4. This colourless liquid is one of several binary phosphorus hydrides. It is the impurity that typically causes samples of phosphine to ignite in air.
Proper ...
(P
2H
4) is an analogue of
hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...
.
Oxoacids
Phosphorous oxoacids are extensive, often commercially important, and sometimes structurally complicated. They all have acidic protons bound to oxygen atoms, some have nonacidic protons that are bonded directly to phosphorus and some contain phosphorus - phosphorus bonds.
Although many oxoacids of phosphorus are formed, only nine are commercially important, and three of them,
hypophosphorous acid
Hypophosphorous acid (HPA), or phosphinic acid, is a phosphorus oxyacid and a powerful reducing agent with molecular formula H3PO2. It is a colorless low-melting compound, which is soluble in water, dioxane
and alcohols. The formula for this ...
,
phosphorous acid
Phosphorous acid (or phosphonic acid (singular)) is the compound described by the formula H3PO3. This acid is diprotic (readily ionizes two protons), not triprotic as might be suggested by this formula. Phosphorous acid is an intermediate in th ...
, and phosphoric acid, are particularly important.
Nitrides
The PN molecule is considered unstable, but is a product of crystalline
phosphorus nitride Phosphorus nitride refers to several chemical compounds of phosphorus and nitrogen:
* Phosphorus mononitride
* Tetraphosphorus hexanitride
*Triphosphorus pentanitride
Triphosphorus pentanitride is an inorganic compound with the chemical formula . ...
decomposition at 1100 K. Similarly, H
2PN is considered unstable, and phosphorus nitride halogens like F
2PN, Cl
2PN, Br
2PN, and I
2PN oligomerise into cyclic
Polyphosphazene
Polyphosphazenes include a wide range of hybrid inorganic- organic polymers with a number of different skeletal architectures with the backbone P- N-P-N-P-N-. In nearly all of these materials two organic side groups are attached to each phosphor ...
s. For example, compounds of the formula (PNCl
2)
''n'' exist mainly as rings such as the
trimer hexachlorophosphazene
Hexachlorophosphazene is an inorganic compound with the formula . The molecule has a cyclic, unsaturated backbone consisting of alternating phosphorus and nitrogen centers, and can be viewed as a trimer of the hypothetical compound . Its classif ...
. The phosphazenes arise by treatment of phosphorus pentachloride with ammonium chloride:
PCl5 + NH4Cl → 1/''n'' (NPCl2)''n'' + 4 HCl
When the chloride groups are replaced by
alkoxide
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organic substituent. Alkoxides are strong bases and, whe ...
(RO
−), a family of polymers is produced with potentially useful properties.
Sulfides
Phosphorus forms a wide range of sulfides, where the phosphorus can be in P(V), P(III) or other oxidation states. The three-fold symmetric P
4S
3 is used in strike-anywhere matches. P
4S
10 and P
4O
10 have analogous structures. Mixed oxyhalides and oxyhydrides of phosphorus(III) are almost unknown.
Organophosphorus compounds
Compounds with P-C and P-O-C bonds are often classified as organophosphorus compounds. They are widely used commercially. The PCl
3 serves as a source of P
3+ in routes to organophosphorus(III) compounds. For example, it is the precursor to
triphenylphosphine
Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to P Ph3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists a ...
:
:PCl
3 + 6 Na + 3 C
6H
5Cl → P(C
6H
5)
3 + 6 NaCl
Treatment of phosphorus trihalides with alcohols and
phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it req ...
s gives phosphites, e.g.
triphenylphosphite
Triphenyl phosphite is the organophosphorus compound with the formula P(OC6H5)3. It is a colourless viscous liquid.
Preparation
Triphenylphosphite is prepared from phosphorus trichloride and phenol in the presence of a catalytic amount of base:
...
:
:PCl
3 + 3 C
6H
5OH → P(OC
6H
5)
3 + 3 HCl
Similar reactions occur for
phosphorus oxychloride
Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula . It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from pho ...
, affording
triphenylphosphate:
:OPCl
3 + 3 C
6H
5OH → OP(OC
6H
5)
3 + 3 HCl
History
Etymology
The name ''Phosphorus'' in Ancient Greece was the name for the planet
Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...
and is derived from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
words (φῶς = light, φέρω = carry), which roughly translates as light-bringer or light carrier.
(In
Greek mythology
A major branch of classical mythology, Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the Cosmogony, origin and Cosmology#Metaphysical co ...
and tradition, Augerinus (Αυγερινός = morning star, still in use today), Hesperus or Hesperinus (΄Εσπερος or Εσπερινός or Αποσπερίτης = evening star, still in use today) and Eosphorus (Εωσφόρος = dawnbearer, not in use for the planet after Christianity) are close homologues, and also associated with
Phosphorus-the-morning-star).
According to the Oxford English Dictionary, the correct spelling of the element is ''phosphorus''. The word ''phosphorous'' is the adjectival form of the P
3+ valence: so, just as
sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...
forms ''sulfurous'' and ''sulfuric'' compounds, phosphorus forms phosphorous compounds (e.g.,
phosphorous acid
Phosphorous acid (or phosphonic acid (singular)) is the compound described by the formula H3PO3. This acid is diprotic (readily ionizes two protons), not triprotic as might be suggested by this formula. Phosphorous acid is an intermediate in th ...
) and P
5+ valence phosphoric compounds (e.g.,
phosphoric acids and phosphates
A phosphoric acid, in the general sense, is a phosphorus oxoacid in which each phosphorus (P) atom is in the oxidation state +5, and is bonded to four oxygen (O) atoms, one of them through a double bond, arranged as the corners of a tetrahedron. ...
).
Discovery
![Robert boyle](https://upload.wikimedia.org/wikipedia/commons/5/59/Robert_Boyle.jpg)
The discovery of phosphorus, the first element to be discovered that was not known since ancient times, is credited to the German alchemist
Hennig Brand
Hennig Brand (; c. 1630c. 1692 or c. 1710) was a German alchemist who lived and worked in Hamburg. In 1669, Brand accidentally discovered the chemical element phosphorus while searching for the "philosopher's stone", a substance which was believed ...
in 1669, although others might have discovered phosphorus around the same time.
Brand experimented with
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excretion, excreted from the body through the urethra.
Cel ...
, which contains considerable quantities of dissolved phosphates from normal metabolism.
Working in
Hamburg
(male), (female) en, Hamburger(s),
Hamburgian(s)
, timezone1 = Central (CET)
, utc_offset1 = +1
, timezone1_DST = Central (CEST)
, utc_offset1_DST = +2
, postal ...
, Brand attempted to create the fabled
philosopher's stone
The philosopher's stone or more properly philosophers' stone (Arabic: حجر الفلاسفة, , la, lapis philosophorum), is a mythic alchemical substance capable of turning base metals such as mercury into gold (, from the Greek , "gold", a ...
through the
distillation
Distillation, or classical distillation, is the process of separation process, separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distilla ...
of some
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
s by evaporating urine, and in the process produced a white material that glowed in the dark and burned brilliantly. It was named ''phosphorus mirabilis'' ("miraculous bearer of light").
[Schmundt, Hilmar (21 April 2010)]
"Experts Warn of Impending Phosphorus Crisis"
''Der Spiegel
''Der Spiegel'' (, lit. ''"The Mirror"'') is a German weekly news magazine published in Hamburg. With a weekly circulation of 695,100 copies, it was the largest such publication in Europe in 2011. It was founded in 1947 by John Seymour Chaloner ...
''.
Brand's process originally involved letting urine stand for days until it gave off a terrible smell. Then he boiled it down to a paste, heated this paste to a high temperature, and led the vapours through water, where he hoped they would condense to gold. Instead, he obtained a white, waxy substance that glowed in the dark. Brand had discovered phosphorus. Specifically, Brand produced ammonium sodium hydrogen phosphate, . While the quantities were essentially correct (it took about of urine to make about 60 g of phosphorus), it was unnecessary to allow the urine to rot first. Later scientists discovered that fresh urine yielded the same amount of phosphorus.
Brand at first tried to keep the method secret, but later sold the recipe for 200 thalers to D. Krafft from Dresden.
Krafft toured much of Europe with it, including England, where he met with
Robert Boyle
Robert Boyle (; 25 January 1627 – 31 December 1691) was an Anglo-Irish natural philosopher, chemist, physicist, alchemist and inventor. Boyle is largely regarded today as the first modern chemist, and therefore one of the founders of ...
. The secret—that the substance was made from urine—leaked out, and
Johann Kunckel (1630–1703) was able to reproduce it in Sweden (1678). Later, Boyle in London (1680) also managed to make phosphorus, possibly with the aid of his assistant,
Ambrose Godfrey-Hanckwitz. Godfrey later made a business of the manufacture of phosphorus.
Boyle states that Krafft gave him no information as to the preparation of phosphorus other than that it was derived from "somewhat that belonged to the body of man". This gave Boyle a valuable clue, so that he, too, managed to make phosphorus, and published the method of its manufacture.
Later he improved Brand's process by using sand in the reaction (still using urine as base material),
: 4 + 2 + 10 C → 2 + 10 CO +
Robert Boyle was the first to use phosphorus to ignite sulfur-tipped wooden splints, forerunners of our modern matches, in 1680.
Phosphorus was the 13th element to be discovered. Because of its tendency to spontaneously combust when left alone in air, it is sometimes referred to as "the Devil's element".
Bone ash and guano
Antoine Lavoisier
Antoine-Laurent de Lavoisier ( , ; ; 26 August 17438 May 1794), When reduced without charcoal, it gave off an air which supported respiration and combustion in an enhanced way. He concluded that this was just a pure form of common air and th ...
recognized phosphorus as an element in 1777 after
Johan Gottlieb Gahn
Johan Gottlieb Gahn (19 August 1745 – 8 December 1818) was a Swedish chemist and metallurgist who isolated manganese in 1774.
Gahn studied in Uppsala 1762 – 1770 and became acquainted with chemists Torbern Bergman and Carl Wilhelm Scheele. 177 ...
and
Carl Wilhelm Scheele
Carl Wilhelm Scheele (, ; 9 December 1742 – 21 May 1786) was a Swedish German pharmaceutical chemist.
Scheele discovered oxygen (although Joseph Priestley published his findings first), and identified molybdenum, tungsten, barium, hydrog ...
, in 1769, showed that calcium phosphate () is found in bones by obtaining elemental phosphorus from
bone ash
Bone ash is a white material produced by the calcination of bones. Typical bone ash consists of about 55.82% calcium oxide, 42.39% phosphorus pentoxide, and 1.79% water. The exact composition of these compounds varies depending upon the type of bon ...
.
Bone ash was the major source of phosphorus until the 1840s. The method started by roasting bones, then employed the use of
fire clay
Fire clay is a range of refractory clays used in the manufacture of ceramics, especially fire brick. The United States Environmental Protection Agency defines fire clay very generally as a "mineral aggregate composed of hydrous silicates of alumin ...
retorts
In a chemistry laboratory, a retort is a device used for distillation or dry distillation of substances. It consists of a spherical vessel with a long downward-pointing neck. The liquid to be distilled is placed in the vessel and heated. The ...
encased in a very hot brick furnace to distill out the highly toxic elemental phosphorus product. Alternately, precipitated phosphates could be made from ground-up bones that had been de-greased and treated with strong acids. White phosphorus could then be made by heating the precipitated phosphates, mixed with ground coal or
charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, cal ...
in an iron pot, and distilling off phosphorus vapour in a
retort
In a chemistry laboratory, a retort is a device used for distillation or dry distillation of substances. It consists of a spherical vessel with a long downward-pointing neck. The liquid to be distilled is placed in the vessel and heated. The n ...
.
Carbon monoxide
Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
and other flammable gases produced during the reduction process were burnt off in a
flare stack
A gas flare, alternatively known as a flare stack, flare boom, ground flare, or flare pit is a gas combustion device used in places such as petroleum refineries, chemical plants and natural gas processing plants, oil or gas extraction sites havi ...
.
In the 1840s, world phosphate production turned to the mining of tropical island deposits formed from bird and bat
guano
Guano (Spanish from qu, wanu) is the accumulated excrement of seabirds or bats. As a manure, guano is a highly effective fertilizer due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. G ...
(see also
Guano Islands Act
The Guano Islands Act (, enacted August 18, 1856, codified at §§ 1411-1419) is a United States federal law passed by the U.S. Congress that enables citizens of the United States to take possession, in the name of the United States, of unclai ...
). These became an important source of phosphates for fertiliser in the latter half of the 19th century.
Phosphate rock
Phosphate rock
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxi ...
, which usually contains calcium phosphate, was first used in 1850 to make phosphorus, and following the introduction of the electric arc furnace by
James Burgess Readman
Dr James Burgess Readman FRSE FCS FSSA (c.1850–April 1927) was a Scottish chemist who invented an electric furnace for creating phosphorus invented in 1888 and patented in 1889.
Life
He was born in Glasgow the son of George Readman, a bank ...
in 1888 (patented 1889), elemental phosphorus production switched from the bone-ash heating, to electric arc production from phosphate rock. After the depletion of world guano sources about the same time, mineral phosphates became the major source of phosphate fertiliser production. Phosphate rock production greatly increased after World War II, and remains the primary global source of phosphorus and phosphorus chemicals today. See the article on
peak phosphorus
Peak phosphorus is a concept to describe the point in time when humanity reaches the maximum global production rate of phosphorus as an industrial and commercial raw material. The term is used in an equivalent way to the better-known term peak o ...
for more information on the history and present state of phosphate mining. Phosphate rock remains a feedstock in the fertiliser industry, where it is treated with sulfuric acid to produce various "
superphosphate Triple superphosphate is a component of fertilizer that primarily consists of monocalcium phosphate, Ca(H2PO4)2. Triple superphosphate is obtained by treating phosphate rock with phosphoric acid. Traditional routes for extraction of phosphate rock ...
" fertiliser products.
Incendiaries
White phosphorus was first made commercially in the 19th century for the
match
A match is a tool for starting a fire. Typically, matches are made of small wooden sticks or stiff paper. One end is coated with a material that can be ignited by friction generated by striking the match against a suitable surface. Wooden matc ...
industry. This used bone ash for a phosphate source, as described above. The bone-ash process became obsolete when the
submerged-arc furnace for phosphorus production
The Submerged-arc furnace for phosphorus production is a particular sub-type of electric arc furnace used to produce phosphorus and other products. Submerged arc furnaces are mainly used for the production of ferroalloys. The nomenclature ''subme ...
was introduced to reduce phosphate rock.
[.] The electric furnace method allowed production to increase to the point where phosphorus could be used in weapons of war.
In
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
, it was used in incendiaries,
smoke screen
A smoke screen is smoke released to mask the movement or location of military units such as infantry, tanks, aircraft, or ships.
Smoke screens are commonly deployed either by a canister (such as a grenade) or generated by a vehicle (such as ...
s and tracer bullets.
A special incendiary bullet was developed to shoot at
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
-filled
Zeppelin
A Zeppelin is a type of rigid airship named after the German inventor Count Ferdinand von Zeppelin () who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874Eckener 1938, pp ...
s over Britain (hydrogen being highly
flammable
A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...
).
During
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
,
Molotov cocktail
A Molotov cocktail (among several other names – ''see other names'') is a hand thrown incendiary weapon constructed from a frangible container filled with flammable substances equipped with a fuse (typically a glass bottle filled with flamma ...
s made of phosphorus dissolved in
petrol
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic co ...
were distributed in Britain to specially selected civilians within the British resistance operation, for defence; and phosphorus incendiary bombs were used in war on a large scale. Burning phosphorus is difficult to extinguish and if it splashes onto human skin it has horrific effects.
Early matches used white phosphorus in their composition, which was dangerous due to its toxicity. Murders, suicides and accidental
poison
Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...
ings resulted from its use. (An apocryphal tale tells of a woman attempting to murder her husband with white phosphorus in his food, which was detected by the stew's giving off luminous steam).
In addition, exposure to the vapours gave match workers a severe
necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...
of the bones of the jaw, known as "
phossy jaw
Phossy jaw, formally known as phosphorus necrosis of the jaw, was an occupational disease affecting those who worked with white phosphorus (also known as ''yellow phosphorus'') without proper safeguards. It was most commonly seen in workers in the ...
". When a safe process for manufacturing red phosphorus was discovered, with its far lower flammability and toxicity, laws were enacted, under the
Berne Convention (1906)
__NOTOC__
The Berne Convention (formally, the International Convention respecting the Prohibition of the Use of White (Yellow) Phosphorus in the Manufacture of Matches (french: Convention internationale sur l'interdiction de l'emploi du phosphore ...
, requiring its adoption as a safer alternative for match manufacture.
The toxicity of white phosphorus led to discontinuation of its use in matches. The Allies used phosphorus
incendiary bomb
Incendiary weapons, incendiary devices, incendiary munitions, or incendiary bombs are weapons designed to start fires or destroy sensitive equipment using fire (and sometimes used as anti-personnel weaponry), that use materials such as napalm, t ...
s in
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
to destroy Hamburg, the place where the "miraculous bearer of light" was first discovered.
Production
In 2017, the USGS estimated 68 billion tons of world reserves, where reserve figures refer to the amount assumed recoverable at current market prices; 0.261 billion tons were mined in 2016. Critical to contemporary agriculture, its annual demand is rising nearly twice as fast as the growth of the human population.
The production of phosphorus may have peaked before 2011 and some scientists predict reserves will be depleted in before the end of the 21st Century."
Phosphorus comprises about 0.1% by mass of the average rock, and consequently, the Earth's supply is vast, though dilute.
Wet process
Most phosphorus-bearing material is for agriculture fertilisers. In this case where the standards of purity are modest, phosphorus is obtained from phosphate rock by what is called the "wet process." The minerals are treated with sulfuric acid to give
phosphoric acid
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...
. Phosphoric acid is then neutralized to give various phosphate salts, which comprise fertilizers. In the wet process, phosphorus does not undergo redox.
[ About five tons of ]phosphogypsum
Phosphogypsum (PG) is the calcium sulfate hydrate formed as a by-product of the production of fertilizer from phosphate rock. It is mainly composed of gypsum (CaSO4·2H2O). Although gypsum is a widely used material in the construction industry, ...
waste are generated per ton of phosphoric acid production. Annually, the estimated generation of phosphogypsum worldwide is 100 to 280 Mt.
Thermal process
For the use of phosphorus in drugs, detergents, and foodstuff, the standards of purity are high, which led to the development of the thermal process. In this process, phosphate minerals are converted to white phosphorus, which can be purified by distillation. The white phosphorus is then oxidised to phosphoric acid and subsequently neutralised with a base to give phosphate salts. The thermal process is energy intensive. Presently, about of elemental phosphorus is produced annually. Calcium phosphate (phosphate rock), mostly mined in Florida and North Africa, can be heated to 1,200–1,500 °C with sand, which is mostly , and coke to produce . The product, being volatile, is readily isolated:
:4 Ca5(PO4)3F + 18 SiO2 + 30 C → 3 P4 + 30 CO + 18 CaSiO3 + 2 CaF2
:2 Ca3(PO4)2 + 6 SiO2 + 10 C → 6 CaSiO3 + 10 CO + P4
Side products from the thermal process include ferrophosphorus, a crude form of Fe2P, resulting from iron impurities in the mineral precursors. The silicate slag
Slag is a by-product of smelting (pyrometallurgical) ores and used metals. Broadly, it can be classified as ferrous (by-products of processing iron and steel), ferroalloy (by-product of ferroalloy production) or non-ferrous/base metals (by-prod ...
is a useful construction material. The fluoride is sometimes recovered for use in water fluoridation
Water fluoridation is the controlled adjustment of fluoride to a public water supply solely to reduce tooth decay. Fluoridated water contains fluoride at a level that is effective for preventing cavities; this can occur naturally or by adding ...
. More problematic is a "mud" containing significant amounts of white phosphorus. Production of white phosphorus is conducted in large facilities in part because it is energy intensive. The white phosphorus is transported in molten form. Some major accidents have occurred during transportation.
Historical routes
Historically, before the development of mineral-based extractions, white phosphorus was isolated on an industrial scale from bone ash. In this process, the tricalcium phosphate
Tricalcium phosphate (sometimes abbreviated TCP) is a calcium salt of phosphoric acid with the chemical formula Ca3(PO4)2. It is also known as tribasic calcium phosphate and bone phosphate of lime (BPL). It is a white solid of low solubility. Mo ...
in bone ash is converted to monocalcium phosphate
Monocalcium phosphate is an inorganic compound with the chemical formula Ca(H2PO4)2 ("AMCP" or "CMP-A" for anhydrous monocalcium phosphate). It is commonly found as the monohydrate ("MCP" or "MCP-M"), Ca(H2PO4)2·H2O. Both salts are colourless sol ...
with sulfuric acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...
:
:Ca3(PO4)2 + 2 H2SO4 → Ca(H2PO4)2 + 2 CaSO4
Monocalcium phosphate
Monocalcium phosphate is an inorganic compound with the chemical formula Ca(H2PO4)2 ("AMCP" or "CMP-A" for anhydrous monocalcium phosphate). It is commonly found as the monohydrate ("MCP" or "MCP-M"), Ca(H2PO4)2·H2O. Both salts are colourless sol ...
is then dehydrated to the corresponding metaphosphate:
:Ca(H2PO4)2 → Ca(PO3)2 + 2 H2O
When ignited to a white heat (~1300C) with charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, cal ...
, calcium metaphosphate yields two-thirds of its weight of white phosphorus while one-third of the phosphorus remains in the residue as calcium orthophosphate:
:3 Ca(PO3)2 + 10 C → Ca3(PO4)2 + 10 CO + P4
Applications
Food additive
Phosphorus is an essential mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...
for humans listed in the Dietary Reference Intake
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Reco ...
(DRI).
Food-grade phosphoric acid
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...
(additive E338
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, ...
) is used to acidify foods and beverages such as various cola
Cola is a carbonated soft drink flavored with vanilla, cinnamon, citrus oils and other flavorings. Cola became popular worldwide after the American pharmacist John Stith Pemberton invented Coca-Cola, a trademarked brand, in 1886, which was imita ...
s and jams, providing a tangy or sour taste. The phosphoric acid also serves as a preservative
A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or by ...
. Soft drinks containing phosphoric acid, which would include Coca-Cola
Coca-Cola, or Coke, is a carbonated soft drink manufactured by the Coca-Cola Company. Originally marketed as a temperance drink and intended as a patent medicine, it was invented in the late 19th century by John Stith Pemberton in Atlanta ...
, are sometimes called phosphate soda
Phosphate soda is a type of beverage that has a tangy or sour taste. These beverages became popular among children in the 1870s in the United States. Phosphate beverages were made with fruit flavorings, egg, malt, or wine. In the 1900s, the bever ...
s or phosphates. Phosphoric acid in soft drinks has the potential to cause dental erosion. Phosphoric acid also has the potential to contribute to the formation of kidney stones
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
, especially in those who have had kidney stones previously.
Fertiliser
Phosphorus is an essential plant nutrient (the most often limiting nutrient, after nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
), and the bulk of all phosphorus production is in concentrated phosphoric acids for agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...
fertiliser
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
s, containing as much as 70% to 75% P2O5. That led to large increase in phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phospho ...
(PO43−) production in the second half of the 20th century. Artificial phosphate fertilisation is necessary because phosphorus is essential to all living organisms; it is involved in energy transfers, strength of root and stems, photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...
, the expansion of plant roots
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the sur ...
, formation of seeds and flowers, and other important factors effecting overall plant health and genetics.
Natural phosphorus-bearing compounds are mostly inaccessible to plants because of the low solubility and mobility in soil. Most phosphorus is very stable in the soil minerals or organic matter of the soil. Even when phosphorus is added in manure or fertilizer it can become fixed in the soil. Therefore, the natural cycle of phosphorus is very slow. Some of the fixed phosphorus is released again over time, sustaining wild plant growth, however, more is needed to sustain intensive cultivation of crops. Fertiliser is often in the form of superphosphate of lime, a mixture of calcium dihydrogen phosphate (Ca(H2PO4)2), and calcium sulfate dihydrate (CaSO4·2H2O) produced reacting sulfuric acid and water with calcium phosphate.
Processing phosphate minerals with sulfuric acid for obtaining fertiliser is so important to the global economy that this is the primary industrial market for sulfuric acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...
and the greatest industrial use of elemental sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...
.
Organophosphorus
White phosphorus is widely used to make organophosphorus compound
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective in ...
s through intermediate phosphorus chlorides and two phosphorus sulfides, phosphorus pentasulfide
Phosphorus pentasulfide is the inorganic compound with the formula (monomer) or (dimer). This yellow solid is the one of two phosphorus sulfides of commercial value. Samples often appear greenish-gray due to impurities. It is soluble in carbon d ...
and phosphorus sesquisulfide
Phosphorus sesquisulfide is the inorganic compound with the formula . It was developed by Henri Sevene and Emile David Cahen in 1898 as part of their invention of friction matches that did not pose the health hazards of white phosphorus. This y ...
. Organophosphorus compounds have many applications, including in plasticisers, flame retardant
The term flame retardants subsumes a diverse group of chemicals that are added to manufactured materials, such as plastics and textiles, and surface finishes and coatings. Flame retardants are activated by the presence of an ignition source a ...
s, pesticide
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...
s, extraction agents, nerve agents and water treatment
Water treatment is any process that improves the Water quality, quality of water to make it appropriate for a specific end-use. The end use may be drinking water, drinking, industrial water supply, irrigation, river flow maintenance, water recrea ...
.
Metallurgical aspects
Phosphorus is also an important component in steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
production, in the making of phosphor bronze
Phosphor bronze is a member of the family of copper alloys. It is composed of copper that is alloyed with 0.5–11% of tin and 0.01–0.35% phosphorus, and may contain other elements to confer specific properties (e.g. lead at 0.5–3.0% to form ...
, and in many other related products. Phosphorus is added to metallic copper during its smelting process to react with oxygen present as an impurity in copper and to produce phosphorus-containing copper (CuOFP
Oxygen-free copper (OFC) or oxygen-free high thermal conductivity (OFHC) copper is a group of wrought high-conductivity copper alloys that have been electrolytically refined to reduce the level of oxygen to 0.001% or below.
Specification
...
) alloys with a higher hydrogen embrittlement
Hydrogen embrittlement (HE), also known as hydrogen-assisted cracking or hydrogen-induced cracking (HIC), is a reduction in the ductility of a metal due to absorbed hydrogen. Hydrogen atoms are small and can permeate solid metals. Once absorbed ...
resistance than normal copper.
Matches
The first striking match with a phosphorus head was invented by Charles Sauria in 1830. These matches (and subsequent modifications) were made with heads of white phosphorus, an oxygen-releasing compound (potassium chlorate
Potassium chlorate is a compound containing potassium, chlorine and oxygen, with the molecular formula KClO3. In its pure form, it is a white crystalline substance. After sodium chlorate, it is the second most common chlorate in industrial use. It ...
, lead dioxide
Lead(IV) oxide is the inorganic compound with the formula PbO2. It is an oxide where lead is in an oxidation state of +4. It is a dark-brown solid which is insoluble in water. It exists in two crystalline forms. It has several important applicatio ...
, or sometimes nitrate
Nitrate is a polyatomic ion
A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...
), and a binder. They were poisonous to the workers in manufacture, sensitive to storage conditions, toxic if ingested, and hazardous when accidentally ignited on a rough surface. Production in several countries was banned between 1872 and 1925. The international Berne Convention
The Berne Convention for the Protection of Literary and Artistic Works, usually known as the Berne Convention, was an international assembly held in 1886 in the Swiss city of Bern by ten European countries with the goal to agree on a set of leg ...
, ratified in 1906, prohibited the use of white phosphorus in matches.
In consequence, phosphorous matches were gradually replaced by safer alternatives. Around 1900 French chemists Henri Sévène and Emile David Cahen invented the modern strike-anywhere match, wherein the white phosphorus was replaced by phosphorus sesquisulfide
Phosphorus sesquisulfide is the inorganic compound with the formula . It was developed by Henri Sevene and Emile David Cahen in 1898 as part of their invention of friction matches that did not pose the health hazards of white phosphorus. This y ...
(P4S3), a non-toxic and non-pyrophoric compound that ignites under friction. For a time these safer strike-anywhere matches were quite popular but in the long run they were superseded by the modern safety match.
Safety matches are very difficult to ignite on any surface other than a special striker strip. The strip contains non-toxic red phosphorus and the match head potassium chlorate
Potassium chlorate is a compound containing potassium, chlorine and oxygen, with the molecular formula KClO3. In its pure form, it is a white crystalline substance. After sodium chlorate, it is the second most common chlorate in industrial use. It ...
, an oxygen-releasing compound. When struck, small amounts of abrasion from match head and striker strip are mixed intimately to make a small quantity of Armstrong's mixture, a very touch sensitive composition. The fine powder ignites immediately and provides the initial spark to set off the match head. Safety matches separate the two components of the ignition mixture until the match is struck. This is the key safety advantage as it prevents accidental ignition. Nonetheless, safety matches, invented in 1844 by Gustaf Erik Pasch
Gustaf Erik Pasch (born Berggren) (3 September 1788 – 6 September 1862) was a Swedish inventor and professor of chemistry at Karolinska institute in Stockholm and inventor of the safety match. He was born in Norrköping, the son of a carpenter. ...
and market ready by the 1860s, didn't gain consumer acceptance until the prohibition of white phosphorus. Using a dedicated striker strip was considered clumsy.
Water softening
made from phosphoric acid is used in laundry detergents in some countries, but banned for this use in others. This compound softens the water to enhance the performance of the detergents and to prevent pipe/boiler tube corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...
.
Miscellaneous
* Phosphates are used to make special glasses for sodium lamp
A sodium-vapor lamp is a gas-discharge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589 nm.
Two varieties of such lamps exist: low pressure and high pressure. Low-pressure sodium lamps are ...
s.
* Bone-ash, calcium phosphate
The term calcium phosphate refers to a family of materials and minerals containing calcium ions (Ca2+) together with inorganic phosphate anions. Some so-called calcium phosphates contain oxide and hydroxide as well. Calcium phosphates are white ...
, is used in the production of fine china.
* Phosphoric acid made from elemental phosphorus is used in food applications such as soft drinks
A soft drink (see § Terminology for other names) is a drink that usually contains water (often carbonated), a sweetener, and a natural and/or artificial flavoring. The sweetener may be a sugar, high-fructose corn syrup, fruit juice, a s ...
, and as a starting point for food grade phosphates. These include mono-calcium phosphate for baking powder
Baking powder is a dry chemical leavening agent, a mixture of a carbonate or bicarbonate and a weak acid. The base and acid are prevented from reacting prematurely by the inclusion of a buffer such as cornstarch. Baking powder is used to increase ...
and . Phosphates are used to improve the characteristics of processed meat and cheese
Cheese is a dairy product produced in wide ranges of flavors, textures, and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk, usually the milk of cows, buffalo, goats, or sheep. During production, ...
, and in toothpaste.
* White phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus.
White phosphorus
White ...
, called "WP" (slang term "Willie Peter") is used in military
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct ...
applications as incendiary bombs
Incendiary weapons, incendiary devices, incendiary munitions, or incendiary bombs are weapons designed to start fires or destroy sensitive equipment using fire (and sometimes used as anti-personnel weaponry), that use materials such as napalm, th ...
, for smoke-screen
A smoke screen is smoke released to mask the movement or location of military units such as infantry, tanks, aircraft, or ships.
Smoke screens are commonly deployed either by a canister (such as a grenade) or generated by a vehicle (such ...
ing as smoke pots and smoke bomb
A smoke bomb is a firework designed to produce a large amount of smoke upon ignition.
History
Early Japanese history saw the use of a rudimentary form of the smoke bomb. Explosives were common in Japan during the Mongol invasions of the 13th ...
s, and in tracer ammunition
Tracer ammunition (AMO) (Tracers) are bullets or cannon-caliber projectiles that are built with a small pyrotechnic charge in their base. When fired, the pyrotechnic composition is ignited by the burning powder and burns very brightly, making t ...
. It is also a part of an obsolete M34 White Phosphorus US hand grenade. This multipurpose grenade was mostly used for signaling, smoke screens, and inflammation; it could also cause severe burns and had a psychological impact on the enemy. Military uses of white phosphorus are constrained by international law.
* 32P and 33P are used as radioactive tracers in biochemical laboratories.
Biological role
Inorganic phosphorus in the form of the phosphate is required for all known forms of life
Life is a quality that distinguishes matter that has biological processes, such as signaling and self-sustaining processes, from that which does not, and is defined by the capacity for growth, reaction to stimuli, metabolism, energ ...
. Phosphorus plays a major role in the structural framework of DNA and RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
. Living cells use phosphate to transport cellular energy with adenosine triphosphate
Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of ...
(ATP), necessary for every cellular process that uses energy. ATP is also important for phosphorylation
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, wh ...
, a key regulatory event in cells. Phospholipid
Phospholipids, are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typ ...
s are the main structural components of all cellular membranes. Calcium phosphate
The term calcium phosphate refers to a family of materials and minerals containing calcium ions (Ca2+) together with inorganic phosphate anions. Some so-called calcium phosphates contain oxide and hydroxide as well. Calcium phosphates are white ...
salts assist in stiffening bone
A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...
s. Biochemists commonly use the abbreviation "Pi" to refer to inorganic phosphate.
Every living cell is encased in a membrane that separates it from its surroundings. Cellular membranes are composed of a phospholipid matrix and proteins, typically in the form of a bilayer. Phospholipids are derived from glycerol
Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known ...
with two of the glycerol hydroxyl (OH) protons replaced by fatty acids as an ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
, and the third hydroxyl proton has been replaced with phosphate bonded to another alcohol.
An average adult human contains about 0.7 kg of phosphorus, about 85–90% in bones and teeth in the form of apatite
Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal. The formula of the admixture of the three most common e ...
, and the remainder in soft tissues and extracellular fluids (~1%). The phosphorus content increases from about 0.5% by mass in infancy to 0.65–1.1% by mass in adults. Average phosphorus concentration in the blood is about 0.4 g/L, about 70% of that is organic and 30% inorganic phosphates. An adult with healthy diet consumes and excretes about 1–3 grams of phosphorus per day, with consumption in the form of inorganic phosphate and phosphorus-containing biomolecules such as nucleic acids
Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main clas ...
and phospholipids
Phospholipids, are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typ ...
; and excretion almost exclusively in the form of phosphate ions such as and . Only about 0.1% of body phosphate circulates in the blood, paralleling the amount of phosphate available to soft tissue cells.
Bone and teeth enamel
The main component of bone is hydroxyapatite
Hydroxyapatite, also called hydroxylapatite (HA), is a naturally occurring mineral form of calcium apatite with the formula Ca5(PO4)3(OH), but it is usually written Ca10(PO4)6(OH)2 to denote that the crystal unit cell comprises two entities. ...
as well as amorphous forms of calcium phosphate, possibly including carbonate. Hydroxyapatite is the main component of tooth enamel. Water fluoridation
Water fluoridation is the controlled adjustment of fluoride to a public water supply solely to reduce tooth decay. Fluoridated water contains fluoride at a level that is effective for preventing cavities; this can occur naturally or by adding ...
enhances the resistance of teeth to decay by the partial conversion of this mineral to the still harder material called fluoroapatite:
: + → +
Phosphorus deficiency
In medicine, phosphate deficiency syndrome may be caused by malnutrition
Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is "a deficiency, excess, or imbalance of energy, protein and other nutrients" which adversely affects the body's tissues a ...
, by failure to absorb phosphate, and by metabolic syndromes that draw phosphate from the blood (such as in refeeding syndrome after malnutrition) or passing too much of it into the urine. All are characterised by hypophosphatemia
Hypophosphatemia is an electrolyte disorder in which there is a low level of phosphate in the blood. Symptoms may include weakness, trouble breathing, and loss of appetite. Complications may include seizures, coma, rhabdomyolysis, or softening ...
, which is a condition of low levels of soluble phosphate levels in the blood serum and inside the cells. Symptoms of hypophosphatemia include neurological dysfunction and disruption of muscle and blood cells due to lack of ATP. Too much phosphate can lead to diarrhoea and calcification (hardening) of organs and soft tissue, and can interfere with the body's ability to use iron, calcium, magnesium, and zinc.
Phosphorus is an essential macromineral
In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life. However, the four major structural elements in the human body by weight (oxygen, hydrogen, carbon, ...
for plants, which is studied extensively in edaphology
Edaphology (from Greek , ''edaphos'', "ground",, ''-logia'') is concerned with the influence of soils on living beings, particularly plants.
It is one of two main divisions of soil science, the other being pedology. Edaphology includes the study ...
to understand plant uptake from soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...
systems. Phosphorus is a limiting factor
A limiting factor is a variable of a system that causes a noticeable change in output or another measure of a type of system. The limiting factor is in a pyramid shape of organisms going up from the producers to consumers and so on. A factor not l ...
in many ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...
s; that is, the scarcity of phosphorus limits the rate of organism growth. An excess of phosphorus can also be problematic, especially in aquatic systems where eutrophication
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...
sometimes leads to algal blooms.
Nutrition
Dietary recommendations
The U.S. Institute of Medicine (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowance
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Reco ...
s (RDAs) for phosphorus in 1997. If there is not sufficient information to establish EARs and RDAs, an estimate designated Adequate Intake
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Reco ...
(AI) is used instead. The current EAR for phosphorus for people ages 19 and up is 580 mg/day. The RDA is 700 mg/day. RDAs are higher than EARs so as to identify amounts that will cover people with higher than average requirements. RDA for pregnancy and lactation are also 700 mg/day. For people ages 1–18 years the RDA increases with age from 460 to 1250 mg/day. As for safety, the IOM sets Tolerable upper intake level
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Re ...
s (ULs) for vitamins and minerals when evidence is sufficient. In the case of phosphorus the UL is 4000 mg/day. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intake
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Reco ...
s (DRIs).
The European Food Safety Authority
The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain. EFSA was established in February 2002, ...
(EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL defined the same as in United States. For people ages 15 and older, including pregnancy and lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The proces ...
, the AI is set at 550 mg/day. For children ages 4–10 the AI is 440 mg/day, and for ages 11–17 it is 640 mg/day. These AIs are lower than the U.S RDAs. In both systems, teenagers need more than adults. The European Food Safety Authority reviewed the same safety question and decided that there was not sufficient information to set a UL.
For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value (%DV). For phosphorus labeling purposes 100% of the Daily Value was 1000 mg, but as of May 27, 2016 it was revised to 1250 mg to bring it into agreement with the RDA. A table of the old and new adult daily values is provided at Reference Daily Intake
The Reference Daily Intake (RDI) used in nutrition labeling on food and dietary supplement products in the U.S. and Canada is the daily intake level of a nutrient that is considered to be sufficient to meet the requirements of 97–98% of health ...
.
Food sources
The main food sources for phosphorus are the same as those containing protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
, although proteins do not contain phosphorus. For example, milk, meat, and soya typically also have phosphorus. As a rule, if a diet has sufficient protein and calcium, the amount of phosphorus is probably sufficient.
Precautions
Organic compounds of phosphorus form a wide class of materials; many are required for life, but some are extremely toxic. Fluorophosphate ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
s are among the most potent neurotoxin
Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature ner ...
s known. A wide range of organophosphorus compounds are used for their toxicity as pesticides
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampric ...
(herbicides
Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page fo ...
, insecticides
Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...
, fungicides
Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, ...
, etc.) and weapon
A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, s ...
ised as nerve agents against enemy humans. Most inorganic phosphates are relatively nontoxic and essential nutrients.
The white phosphorus allotrope presents a significant hazard because it ignites in air and produces phosphoric acid residue. Chronic white phosphorus poisoning leads to necrosis of the jaw called "phossy jaw
Phossy jaw, formally known as phosphorus necrosis of the jaw, was an occupational disease affecting those who worked with white phosphorus (also known as ''yellow phosphorus'') without proper safeguards. It was most commonly seen in workers in the ...
". White phosphorus is toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...
, causing severe liver damage on ingestion and may cause a condition known as "Smoking Stool Syndrome".
In the past, external exposure to elemental phosphorus was treated by washing the affected area with 2% copper sulfate Copper sulfate may refer to:
* Copper(II) sulfate, CuSO4, a common compound used as a fungicide and herbicide
* Copper(I) sulfate
Copper(I) sulfate, also known as cuprous sulfate, is an inorganic compound with the chemical formula Cu2 SO4. It ...
solution to form harmless compounds that are then washed away. According to the recent ''US Navy's Treatment of Chemical Agent Casualties and Conventional Military Chemical Injuries: FM8-285: Part 2 Conventional Military Chemical Injuries'', "Cupric (copper(II)) sulfate has been used by U.S. personnel in the past and is still being used by some nations. However, copper sulfate is toxic and its use will be discontinued. Copper sulfate may produce kidney and cerebral toxicity as well as intravascular hemolysis."
The manual suggests instead "a bicarbonate solution to neutralise phosphoric acid, which will then allow removal of visible white phosphorus. Particles often can be located by their emission of smoke when air strikes them, or by their phosphorescence in the dark. In dark surroundings, fragments are seen as luminescent spots. Promptly debride
Debridement is the medical removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue. Removal may be surgical, mechanical, chemical, autolytic (self-digestion), and by maggot therapy.
In po ...
the burn if the patient's condition will permit removal of bits of WP (white phosphorus) that might be absorbed later and possibly produce systemic poisoning. DO NOT apply oily-based ointments
A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...
until it is certain that all WP has been removed. Following complete removal of the particles, treat the lesions as thermal burns." As white phosphorus readily mixes with oils, any oily substances or ointments are not recommended until the area is thoroughly cleaned and all white phosphorus removed.
People can be exposed to phosphorus in the workplace by inhalation, ingestion, skin contact, and eye contact. The Occupational Safety and Health Administration
The Occupational Safety and Health Administration'' (OSHA ) is a large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agenc ...
(OSHA) has set the phosphorus exposure limit (Permissible exposure limit
The permissible exposure limit (PEL or OSHA PEL) is a legal limit in the United States for exposure of an employee to a chemical substance or physical agent such as high level noise. Permissible exposure limits are established by the Occupational ...
) in the workplace at 0.1 mg/m3 over an 8-hour workday. The National Institute for Occupational Safety and Health
The National Institute for Occupational Safety and Health (NIOSH, ) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the C ...
(NIOSH) has set a Recommended exposure limit
A recommended exposure limit (REL) is an occupational exposure limit that has been recommended by the United States National Institute for Occupational Safety and Health. The REL is a level that NIOSH believes would be protective of worker safet ...
(REL) of 0.1 mg/m3 over an 8-hour workday. At levels of 5 mg/m3, phosphorus is immediately dangerous to life and health
The term immediately dangerous to life or health (IDLH) is defined by the US National Institute for Occupational Safety and Health (NIOSH) as exposure to airborne contaminants that is "likely to cause death or immediate or delayed permanent advers ...
.
US DEA List I status
Phosphorus can reduce elemental iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...
to hydroiodic acid
Hydroiodic acid (or hydriodic acid) is an aqueous solution of hydrogen iodide (HI). It is a strong acid, one that is ionized completely in an aqueous solution. It is colorless. Concentrated solutions are usually 48% to 57% HI.
Reactions
Hyd ...
, which is a reagent effective for reducing ephedrine
Ephedrine is a central nervous system (CNS) stimulant that is often used to prevent low blood pressure during anesthesia. It has also been used for asthma, narcolepsy, and obesity but is not the preferred treatment. It is of unclear benefit in ...
or pseudoephedrine
Pseudoephedrine (PSE) is a sympathomimetic drug of the phenethylamine and amphetamine chemical classes. It may be used as a nasal/sinus decongestant, as a stimulant, or as a wakefulness-promoting agent in higher doses.
It was first characteri ...
to methamphetamine
Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug and less commonly as a second-line treatment for attention deficit hyperactivity disorder and obesity. Methamph ...
. For this reason, red and white phosphorus were designated by the United States Drug Enforcement Administration
The Drug Enforcement Administration (DEA; ) is a Federal law enforcement in the United States, United States federal law enforcement agency under the U.S. Department of Justice tasked with combating drug trafficking and distribution within th ...
as List I precursor chemicals under 21 CFR 1310.02 effective on November 17, 2001. In the United States, handlers of red or white phosphorus are subject to stringent regulatory controls.
See also
* Phosphorus cycle
The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the Earth's atmosphere, atmosphere does not play a significan ...
Notes
References
Bibliography
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Chemical elements
Pnictogens
Reactive nonmetals
Polyatomic nonmetals
Dietary minerals
Pyrotechnic fuels
Chemical elements with body-centered cubic structure