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Talc, or talcum, is a
clay mineral Clay minerals are , sometimes with variable amounts of , , s, s, and other s found on or near some s. Clay minerals form in the presence of water and have been important to life, and many theories of involve them. They are important constitu ...
, composed of
hydrate In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds composed of atoms, m ...
d
magnesium Magnesium is a chemical element upright=1.0, 500px, The chemical elements ordered by link=Periodic table In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science ...

magnesium
silicate In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds composed of atoms, ...
with the chemical formula Mg3Si4O10(OH)2. Talc in powdered form, often combined with
corn starch Corn starch, maize starch, or cornflour (British English British English (BrE) is the standard dialect A standard language (also standard variety, standard dialect, and standard) is a language variety that has undergone substantial ...
, is used as
baby powder Baby powder is an astringent powder used for preventing diaper rash and for cosmetic uses. It may be composed of talcum (in which case it is also called talcum powder) or corn starch Corn starch, maize starch, or cornflour (British English ...
. This mineral is used as a thickening agent and lubricant; is an ingredient in ceramics, paint, and roofing material; and is a main ingredient in many cosmetics. It occurs as foliated to
fibrous Fiber or fibre (from la, fibra, links=no) is a natural Nature, in the broadest sense, is the natural, physical, material world or universe The universe ( la, universus) is all of space and time and their contents, including ...

fibrous
masses, and in an exceptionally rare
crystal A crystal or crystalline solid is a solid Solid is one of the four fundamental states of matter (the others being liquid A liquid is a nearly incompressible fluid In physics, a fluid is a substance that continually Deformatio ...

crystal
form. It has a perfect basal cleavage and an uneven flat fracture, and it is foliated with a two-dimensional platy form. The
Mohs scale of mineral hardness The Mohs scale of mineral hardness () is a qualitative ordinal scale Ordinal data is a categorical, statistical data type where the variables have natural, ordered categories and the distances between the categories are not known. These data e ...
, based on scratch
hardness comparisonA variety of hardness Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation hardness, indentation or abrasion (mechanical), abrasion. In general, different materials differ in their hardn ...
, defines value 1 as the hardness of talc, the softest mineral. When scraped on a streak plate, talc produces a white streak; though this indicator is of little importance, because most silicate minerals produce a white streak. Talc is translucent to opaque, with colors ranging from whitish grey to green with a vitreous and pearly
luster Lustre or Luster may refer to: Places * Luster, Norway, a municipality in Vestlandet, Norway ** Luster (village), a village in the municipality of Luster * Lustre, Montana, an unincorporated community in the United States Entertainment * Luste ...
. Talc is not soluble in water, and is slightly soluble in dilute
mineral acid A mineral acid (or inorganic acid) is an acid An acid is a molecule or ion An ion () is a particle In the Outline of physical science, physical sciences, a particle (or corpuscule in older texts) is a small wikt:local, localized ph ...
s.
Soapstone Soapstone (also known as steatite or soaprock) is a talc- schist, which is a type of metamorphic rock. It is composed largely of the magnesium Magnesium is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic ...
is a
metamorphic rock , a type of metamorphic rock Metamorphic rocks arise from the transformation of existing rock (geology), rock to new types of rock, in a process called metamorphism upright=1.35, Schematic representation of a metamorphic reaction. Abbreviat ...

metamorphic rock
composed predominantly of talc.


Etymology

The word "talc" derives from Medieval Latin ''talcum'', which in turn originates from ar, طلق ''ṭalq'' which, derives from fa, تالک ''tālk''. In ancient times, the word was used for various related minerals, including talc,
mica Micas ( ) are a group of 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 natural ...

mica
, and
selenite Selenite may refer to: Substances containing selenium *A selenium-containing anion or ionic compound with the SeO32− anion: **Selenite (ion), anion is a selenium oxoanion with the chemical formula SeO32− ***Selenous acid, the conjugate acid, wi ...
.


Formation

Talc dominantly forms from the metamorphism of magnesian minerals such as
serpentine Serpentine may refer to: Music * Serpentine (album), ''Serpentine'' (album), a 2002 goth metal album by Flowing Tears * Serpentine (song), "Serpentine" (song), a 2011 country song by Tiffany * Serpentines (Ingrid Laubrock album), ''Serpentines'' ( ...
,
pyroxene The pyroxenes (commonly abbreviated to ''Px'') are a group of important rock-forming s found in many and . Pyroxenes have the general formula , where X represents (Ca), (Na), (Fe II) or (Mg) and more rarely , or , and Y represents ions of ...
,
amphibole Amphibole () is a group of Silicate minerals, inosilicate minerals, forming prism or needlelike crystals, composed of double chain tetrahedron, tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their s ...

amphibole
, and
olivine The 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. R ...

olivine
, in the presence of carbon dioxide and water. This is known as "talc carbonation" or "steatization" and produces a suite of rocks known as
talc carbonate Talc carbonates are a suite of rock and mineral compositions found in metamorphosed ultramafic Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous Igneous rock (derived from the Lati ...
s. Talc is primarily formed by hydration and carbonation by this reaction: : + → + + Talc can also be formed via a reaction between dolomite and silica, which is typical of
skarn Skarns or tactites are hard, coarse-grained metamorphic rocks that form by a process called metasomatism Metasomatism (from the Greek μετά (change) and σῶμα (body)) is the chemical alteration of a rock by hydrothermal and other fluids. ...

skarn
ification of dolomites by silica-flooding in contact metamorphic aureoles: : + + → + + Talc can also be formed from magnesian chlorite and quartz in
blueschist of a thin section vein in mica Mica is a group of sheet silicate minerals, not to be confused with Micah. Mica or MICA may also refer to: Companies * Mica DIY, a UK Retailer Co-operative, Symbol group Acronyms * Mahone Islands Conser ...
and
eclogite (red) and omphacite (greyish-green) groundmass. The sky-blue crystals are kyanite. Minor white quartz is present, presumably from the recrystallization of coesite. A few gold-white phengite patches can be seen at the top. A coin added for scale. ...

eclogite
metamorphism by the following
metamorphic reaction 350px, Schematic representation of a metamorphic reaction. Abbreviations of minerals: act = chlorite The chlorite ion, or chlorine dioxide anion An ion () is a particle, atom or molecule with a net electric charge, electrical charge. Th ...
: :
chlorite The chlorite ion An ion () is a particle In the Outline of physical science, physical sciences, a particle (or corpuscule in older texts) is a small wikt:local, localized physical body, object to which can be ascribed several physical ...
+
quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tetrahedra, ...

quartz
kyanite Kyanite is a typically blue aluminosilicate mineral In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with the solid Earth, the rock ( ...

kyanite
+ talc + water Talc is also found as a diagenetic mineral in sedimentary rocks where it can form from the transformation of metastable hydrated magnesium-clay precursors such as kerolite,
sepiolite Sepiolite, also known in English by the German name meerschaum ( , ; ; meaning "sea foam"), is a soft white clay mineral Clay minerals are hydrous aluminium Aluminium (aluminum in American English, American and Canadian English) is a c ...
, or stevensite that can precipitate from marine and lake water in certain conditions. In this reaction, the ratio of talc and kyanite depends on
aluminium Aluminium (aluminum in and ) is a with the  Al and  13. Aluminium has a density lower than those of other common , at approximately one third that of . It has a great affinity towards , and of on the surface when exposed to air ...

aluminium
content, with more aluminous rocks favoring production of kyanite. This is typically associated with high-pressure, low-temperature minerals such as
phengite Phengite is a series name for dioctahedral micas of composition K(AlMg)2(OH)2(SiAl)4O10 it is common for Mg or Fe2+ to substitute for Al on the Y site and a corresponding increase in Si on the Z site in the mica group formula ''X''2''Y''4–6''Z'' ...
,
garnet Garnets () are a group of silicate mineral Silicate minerals are rock-forming mineral In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science c ...

garnet
, and
glaucophane Glaucophane is the name of a mineral In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with the solid Earth, the rock (geology), rocks o ...

glaucophane
within the lower blueschist facies. Such rocks are typically white, friable, and fibrous, and are known as whiteschist. Talc is a trioctahedral layered mineral; its structure is similar to
pyrophyllite Pyrophyllite is a phyllosilicate Silicate minerals are rock-forming mineral In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with t ...

pyrophyllite
, but with magnesium in the octahedral sites of the composite layers.


Occurrence

Talc is a common metamorphic mineral in metamorphic belts that contain
ultramafic rock Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous Igneous rock (derived from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch ...
s, such as
soapstone Soapstone (also known as steatite or soaprock) is a talc- schist, which is a type of metamorphic rock. It is composed largely of the magnesium Magnesium is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic ...
(a high-talc rock), and within whiteschist and
blueschist of a thin section vein in mica Mica is a group of sheet silicate minerals, not to be confused with Micah. Mica or MICA may also refer to: Companies * Mica DIY, a UK Retailer Co-operative, Symbol group Acronyms * Mahone Islands Conser ...
metamorphic
terrane In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with the solid Earth, the rock (geology), rocks of which it is composed, and the processes ...
s. Prime examples of whiteschists include the Franciscan Metamorphic Belt of the western United States, the western European
Alps The Alps ; german: Alpen ; it, Alpi ; rm, Alps; sl, Alpe ) are the highest and most extensive mountain range A mountain range is a series of mountains ranged in a line and connected by high ground. A mountain system or mountain belt ...

Alps
especially in Italy, certain areas of the
Musgrave Block The Musgrave Block (also known as the Musgrave Province) is an east-west trending belt of Proterozoic granulite-gneiss basement rocks approximately long. The Musgrave Block extends from western South Australia into Western Australia. The Musgrave ...
, and some collisional orogens such as the
Himalayas The Himalayas, or Himalaya (; Sanskrit Sanskrit (; attributively , ; nominalization, nominally , , ) is a classical language of South Asia that belongs to the Indo-Aryan languages, Indo-Aryan branch of the Indo-European languages. It ar ...

Himalayas
, which stretch along
Pakistan Pakistan, . Pronounced variably in English as , , , and . officially the Islamic Republic of Pakistan, is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a popul ...

Pakistan
,
India India, officially the Republic of India (Hindi Hindi (Devanagari: , हिंदी, ISO 15919, ISO: ), or more precisely Modern Standard Hindi (Devanagari: , ISO 15919, ISO: ), is an Indo-Aryan language spoken chiefly in Hindi Belt, ...

India
,
Nepal Nepal (; ne, नेपाल ), officially the Federal Democratic Republic of Nepal ( ne, सङ्घीय लोकतान्त्रिक गणतन्त्र नेपाल ), is a landlocked country in South Asia. It is ma ...

Nepal
, and
Bhutan Bhutan (; dz, འབྲུག་ཡུལ་, Druk Yul, ), officially known as the Kingdom of Bhutan ( dz, འབྲུག་རྒྱལ་ཁབ་, Druk Gyal Khap), is a landlocked country in the Eastern Himalayas. It is bordered by Chin ...

Bhutan
.
Talc carbonate Talc carbonates are a suite of rock and mineral compositions found in metamorphosed ultramafic Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous Igneous rock (derived from the Lati ...
ultramafics are typical of many areas of the
craton A craton (, , or ; from el, κράτος ''kratos'' "strength") is an old and stable part of the continental lithosphere A lithosphere ( grc, λίθος [] for "rocky", and [] for "sphere") is the rigid, outermost shell of a terrestrial p ...
s, notably the komatiite belts of the Yilgarn Craton in Western Australia. Talc-carbonate ultramafics are also known from the
Lachlan Fold BeltThe Lachlan Fold Belt (LFB) or Lachlan Orogen is a geological subdivision of the east part of Australia. It is a zone of folded and faulted rocks of similar age. It dominates New South Wales and Victoria (Australia), Victoria, also extending into Ta ...
, eastern
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Australia
, from
Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At 8.5 million square kilometers (3.2 million square miles) and with over 211 mill ...

Brazil
, the
Guiana Shield The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo Guianês; es, Escudo guayanés) is one of the three craton A craton (, , or ; from el, κράτος ...
, and from the
ophiolite An ophiolite is a section of Earth's oceanic crust The oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates This is a list of tectonic plates on Earth's surface. Tectonic plates are pieces of Earth's crust ...

ophiolite
belts of
Turkey Turkey ( tr, Türkiye ), officially the Republic of Turkey, is a country located mainly on Anatolia Anatolia,, tr, Anadolu Yarımadası), and the Anatolian plateau. also known as Asia Minor, is a large peninsula in Western Asia an ...

Turkey
,
Oman Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is a country on the southeastern coast of the Arabian Peninsula in Western Asia. Formerly a maritime empire, Oman is the oldest continuously in ...

Oman
, and the
Middle East The Middle East ( ar, الشرق الأوسط, ISO 233 The international standard An international standard is a technical standard A technical standard is an established norm (social), norm or requirement for a repeatable technical task whi ...

Middle East
. China is the key world talc and steatite producing country with an output of about 2.2M tonnes(2016), which accounts for 30% of total global output. The other major producers are Brazil (12%), India (11%), the U.S. (9%), France (6%), Finland (4%), Italy, Russia, Canada, and Austria (2%, each). Notable economic talc occurrences include the Mount Seabrook talc mine, Western Australia, formed upon a polydeformed, layered ultramafic intrusion. The France-based Luzenac Group is the world's largest supplier of mined talc. Its largest talc mine at Trimouns near in southern France produces 400,000 
tonne The tonne ( or ; symbol: t) is a metric unit of mass equal to 1,000 kilogram The kilogram (also kilogramme) is the base unit of mass Mass is the physical quantity, quantity of ''matter'' in a physical body. It is also a meas ...
s of talc per year.


Conflict mineral

Extraction in disputed areas of
Nangarhar province Nangarhār (Pashto Pashto (,; / , ), sometimes spelled Pukhto or Pakhto, is an Eastern Iranian language The Eastern Iranian languages are a subgroup of the Iranian languages The Iranian or Iranic languages are a branch of the Indo ...
, Afghanistan, has led the international monitoring group
Global Witness Global Witness is an international NGO established in 1993 that works to break the links between natural resource exploitation, conflict, poverty Poverty is the state of not having enough material possessions or income for a person's basic ...
to declare talc a
conflict resource Conflict resources are natural resource , Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal t ...
, as the profits are used to fund armed confrontation between the
Taliban The Taliban (; ps, طالبان, ṭālibān, lit=students or 'seekers'), which refers to itself as the Islamic Emirate of Afghanistan, Taliban Islamic Movement and/or Islamic Movement of Taliban is a Deobandi Deobandi ( hi, देव ...

Taliban
and
Islamic State , caption = , active = {{Collapsible list , title = 1999–present , 1 = 1999: Established under the name of Jama'at al-Tawhid wal-Jihad , 2 = October 2004: Joined al-Qaeda , 3 = 13 October 2006: Declaration of an Islamic ...
.


Uses

Talc is used in many industries, including paper making,
plastic Plastics are a wide range of syntheticA synthetic is an artificial material produced by organic chemistry, organic chemical synthesis. Synthetic may also refer to: In the sense of both "combination" and "artificial" * Synthetic chemical or s ...

plastic
, paint and coatings (e.g. for metal casting molds), rubber, food, electric cable, pharmaceuticals, cosmetics, and ceramics. A coarse grayish-green high-talc rock is
soapstone Soapstone (also known as steatite or soaprock) is a talc- schist, which is a type of metamorphic rock. It is composed largely of the magnesium Magnesium is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic ...
or
steatite Soapstone (also known as steatite or soaprock) is a talc Talc is a clay mineral, composed of hydrate In chemistry Chemistry is the scientific discipline involved with Chemical element, elements and chemical compound, compounds compose ...
, used for stoves, sinks, electrical switchboards, etc. It is often used for surfaces of laboratory table tops and electrical switchboards because of its resistance to heat, electricity and acids. In finely ground form, talc finds use as a
cosmetic Cosmetic may refer to: *Cosmetics, or make-up, substances to enhance the beauty of the human body, apart from simple cleaning *Cosmetic, an adjective describing beauty, aesthetics, or appearance, especially concerning the human body *Cosmetic, a top ...
(talcum powder), as a
lubricant A lubricant is a substance that helps to reduce friction Friction is the force In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and b ...
, and as a filler in paper manufacture. It is used to coat the insides of inner tubes and rubber gloves during manufacture to keep the surfaces from sticking. Talcum powder, with heavy refinement, has been used in baby powder, an
astringent 200px, A crystal of the astringent alum An astringent (sometimes called adstringent) is a chemical that shrinks or constricts body tissue In biology Biology is the natural science that studies life and living organisms, including thei ...
powder used to prevent
diaper rash Irritant diaper dermatitis (IDD, also called a diaper rash) is a generic term applied to skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate Vertebrates () comprise all species of animal An ...

diaper rash
. The
American Academy of Pediatrics The American Academy of Pediatrics (AAP) is an American professional association A professional association (also called a professional body, professional organization, or professional society) usually seeks to further Further or Furthur ma ...
recommends that parents not use baby powder because it poses a risk of respiratory problems, including breathing trouble and serious lung damage if the baby inhales it. The small size of the particles makes it difficult to keep them out of the air while applying the powder.
Zinc oxide Zinc oxide is an inorganic compound In chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, structure, properties, behavior ...

Zinc oxide
-based ointments are a much safer alternative. It is also often used in
basketball Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular court A court is any person or institution, often as a government institution, with the authority to Adjudication, ...

basketball
to keep a player's hands dry. Most tailor's
chalk Chalk is a soft, white, porous Porosity or void fraction is a measure of the (i.e. "empty") spaces in a , and is a of voids over the total volume, between 0 and 1, or as a between 0% and 100%. Strictly speaking, some tests measure the "acce ...

chalk
, or French chalk, is talc, as is the chalk often used for
welding Welding is a process that joins materials, usually s or s, by using high to melt the parts together and allowing them to cool, causing . Welding is distinct from lower temperature metal-joining techniques such as and , which do not the base ...

welding
or
metalworking Metalworking is the process of shaping and reshaping metal A metal (from Ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearan ...
. Talc is also used as
food additive Food is any substance consumed to provide nutritional support for an organism In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is any individual contiguous system that embodies the Life#Biology ...
or in pharmaceutical products as a glidant. In medicine, talc is used as a
pleurodesis Pleurodesis is a medical procedure in which part of the pleural space is artificially obliterated. It involves the adhesion of the visceral and the costal pleura. The mediastinal pleura is spared. Uses Pleurodesis is performed to prevent recurre ...

pleurodesis
agent to prevent recurrent
pleural effusion A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural fluid is secreted by the parietal pleural capillaries at a rate of 0.01 millilitre per kilo ...

pleural effusion
or
pneumothorax A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and dyspnea, shortness of breath. In a minority of cases, a one-way ...

pneumothorax
. In the
European Union The European Union (EU) is a political and economic union of member states that are located primarily in Europe Europe is a which is also recognised as part of , located entirely in the and mostly in the . It comprises the wester ...

European Union
, the additive number is E553b.
Talc may be used in the processing of white
rice Rice is the seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double album, it was relea ...

rice
as a buffing agent in the polishing stage. Due to its low shear strength, talc is one of the oldest known solid lubricants. Also a limited use of talc as friction-reducing additive in lubricating oils is made. Talc is widely used in the ceramics industry in both bodies and glazes. In low-fire art-ware bodies, it imparts whiteness and increases thermal expansion to resist
crazing Crazing is the phenomenon that produces a network of fine cracks on the surface of a material, for example in a glaze layer. Crazing frequently precedes fracture in some glass Glass is a non- crystalline, often transparency and translucency, ...
. In
stoneware Stoneware is a rather broad term for pottery Pottery is the process and the products of forming vessels and other objects with and other materials, which are fired at high temperatures to give them a hard, durable form. Major types inc ...
s, small percentages of talc are used to flux the body and therefore improve strength and
vitrification Vitrification (from Latin language, Latin ''vitreum'', "glass" via French language, French ''vitrifier'') is the transformation of a substance into a glass, that is to say, a non-Crystallinity, crystalline amorphous solid. Glasses differ from liqu ...
. It is a source of flux in high-temperature glazes (to control melting temperature). It is also employed as a matting agent in earthenware glazes and can be used to produce magnesia mattes at high temperatures. ISO standard for quality (ISO 3262) Patents are pending on the use of magnesium silicate as a cement substitute. Its production requirements are less energy-intensive than ordinary
Portland cement Portland cement is the most common type of cement A cement is a binder (material), binder, a substance used for construction that solidification, sets, hardens, and adheres to other materials to bind them together. Cement is seldom used ...

Portland cement
(at a heating requirement of around 650 °C for talc compared to 1500 °C for limestone to produce Portland cement), while it absorbs far more
carbon dioxide Carbon dioxide (chemical formula A chemical formula is a way of presenting information about the chemical proportions of s that constitute a particular or molecule, using symbols, numbers, and sometimes also other symbols, such as pare ...

carbon dioxide
as it hardens. This results in a negative
carbon footprint A carbon footprint is the total greenhouse gas (GHG) emissions caused by an individual, event, organization, service, place or product, expressed as carbon dioxide equivalent Global warming potential (GWP) is the heat absorbed by any greenhou ...

carbon footprint
overall, as the cement substitute removes 0.6 tonnes of CO2 per tonne used. This contrasts with a positive carbon footprint of 0.4 tonne per tonne of conventional cement.Jha, Alok (31 December 2008
Revealed: The cement that eats carbon dioxide
''The Guardian''
Talc is used in the production of the materials that are widely used in the building interiors such as base content
paint Paint is any pigmented liquid A liquid is a nearly incompressible In fluid mechanics Fluid mechanics is the branch of physics concerned with the mechanics Mechanics (Ancient Greek, Greek: ) is the area of physics concerned wi ...

paint
s in wall coatings. Other areas that use talc to a great extent are organic
agriculture Agriculture is the science, art and practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary Image:Family watching television 1958.jpg, Exercise trends, Increases in sedentary behaviors su ...

agriculture
, food industry, cosmetics, and hygiene products such as baby powder and detergent powder. Talc is sometimes used as an
adulterant An adulterant is a substance found within other substances such as food, cosmetics, pharmaceuticals, fuels, fuel or other chemicals that compromises the safety or effectiveness of said substance. It will not normally be present in any specificati ...
to illegal
heroin Heroin, also known as diacetylmorphine and diamorphine among other names, is an opioid Opioids are substances that act on opioid receptor Opioid receptors are a group of inhibitory G protein-coupled receptors with opioids as ligands. T ...

heroin
, to expand volume and weight and thereby increase its street value. With
intravenous Intravenous therapy (abbreviated as IV therapy) is a medical technique that delivers fluids, medications and nutrition directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrition ...
use, it may lead to pulmonary talcosis, a
granuloma A granuloma is an aggregation of macrophage Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that eng ...

granuloma
tous inflammation in the
lung The lungs are the primary organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A given organ's tissues can be broadly categorized as parenchyma ...

lung
s.


Sterile talc powder

Sterile talc powder ( NDC 63256-200-05) is a sclerosing agent used in the procedure of
pleurodesis Pleurodesis is a medical procedure in which part of the pleural space is artificially obliterated. It involves the adhesion of the visceral and the costal pleura. The mediastinal pleura is spared. Uses Pleurodesis is performed to prevent recurre ...

pleurodesis
. This can be helpful as a
cancer treatment Cancer Cancer is a group of diseases A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not due to any immediate external injury. Diseases a ...
to prevent
pleural effusion A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural fluid is secreted by the parietal pleural capillaries at a rate of 0.01 millilitre per kilo ...

pleural effusion
s (an abnormal collection of fluid in the space between the
lung The lungs are the primary organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A given organ's tissues can be broadly categorized as parenchyma ...

lung
s and the
thoracic wall The thoracic wall or chest wall is the boundary of the thoracic cavity. Structure The bony skeletal part of the thoracic wall is the rib cage, and the rest is made up of muscle Muscle is a soft tissue found in most animals. Muscle cells ...
). It is inserted into the space via a chest tube, causing it to close up, so fluid cannot collect there. The product can be sterilized by dry heat,
ethylene oxide Ethylene oxide is an organic compound In chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, structure, properties, beh ...

ethylene oxide
, or gamma irradiation.


Safety

Suspicions have been raised that talc use contributes to certain types of disease, mainly cancers of the ovaries and lungs. According to the
IARC iArc (iArc Architects) is an internationally awarded architectural practice based in Seoul Seoul (, like ''soul''; ko, 서울 ; ), officially the Seoul Special City, is the Capital city, capital and largest metropolis of South Korea.Before ...
, talc containing asbestos is classified as a group 1 agent (carcinogenic to humans), talc use in the
perineum The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includin ...
is classified as group 2B (possibly carcinogenic to humans), and talc not containing asbestos is classified as group 3 (unclassifiable as to carcinogenicity in humans). Reviews by Cancer Research UK and the American Cancer Society conclude that some studies have found a link, but other studies have not. The studies discuss
pulmonary The lungs are the primary organs of the respiratory system The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animal ...

pulmonary
issues,
lung cancer Lung cancer, also known as lung carcinoma, since about 98–99% of all lung cancers are carcinomas, is a malignant lung tumor characterized by uncontrolled cell growth in tissue (biology), tissues of the lung. Lung carcinomas derive from trans ...

lung cancer
, and
ovarian cancer Ovarian cancer is a cancer that forms in or on an ovary. It results in abnormal cells (biology), cells that have the ability to invade or metastasis, spread to other parts of the body. When this process begins, there may be no or only vague sympto ...
. One of these, published in 1993, was a US National Toxicology Program report, which found that cosmetic grade talc containing no
asbestos Asbestos (pronounced: or ) is a naturally occurring fibrous silicate mineral Silicate minerals are rock-forming mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fair ...
-like fibres was correlated with tumor formation in
rat Rats are various medium-sized, long-tailed rodent Rodents (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area a ...

rat
s forced to inhale talc for 6 hours a day, five days a week over at least 113 weeks. A 1971 paper found particles of talc embedded in 75% of the ovarian tumors studied. Research published in 1995 and 2000 concluded that it was plausible that talc could cause ovarian cancer, but no conclusive evidence was shown. The Cosmetic Ingredient Review Expert Panel concluded in 2015 that talc, in the concentrations currently used in cosmetics, is safe. In 2018, Health Canada issued a warning, advising against inhaling talcum powder or using it in the female perineal area.


Industrial grade

In the United States, 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 The United States Department of Labor (DOL) is a cabinet-level department of the U.S. federal government, re ...
and
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 Injury, also known as physical ...
have set occupational exposure limits to respirable talc dusts at 2 mg/m3 over an eight-hour workday. At levels of 1000 mg/m3, inhalation of talc is considered
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 adverse ...
.


Food grade

The United States
Food and Drug Administration The United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, st ...
considers talc (magnesium silicate)
generally recognized as safe Generally recognized as safe (GRAS) is a United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country in . It consists of 50 , a , five major , 326 , and some . ...
(GRAS) to use as an anticaking agent in table salt in concentrations smaller than 2%.


Association with asbestos

One particular issue with commercial use of talc is its frequent co-location in underground deposits with
asbestos Asbestos (pronounced: or ) is a naturally occurring fibrous silicate mineral Silicate minerals are rock-forming mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fair ...
ore. Asbestos is a general term for different types of fibrous silicate minerals, desirable in construction for their heat resistant properties. There are six varieties of asbestos; the most common variety in manufacturing, white asbestos, is in the serpentine subgroup, serpentine family. Serpentine minerals are sheet silicates; although not in the serpentine family, talc is also a sheet silicate, with two sheets connected by magnesium cations. The frequent co-location of talc deposits with asbestos may result in contamination of mined talc with white asbestos, which poses serious health risks when dispersed into the air and inhaled. Stringent quality control since 1976, including separating cosmetic- and food-grade talc from "industrial"-grade talc, has largely eliminated this issue, but it remains a potential hazard requiring mitigation in the mining and processing of talc. A 2010 US FDA survey failed to find asbestos in a variety of talc-containing products. A 2018 Reuters investigation asserted that pharmaceuticals company Johnson & Johnson knew for decades that there was asbestos in its baby powder, and in 2020 the company stopped selling its baby powder in the US and Canada.


Litigation

In 2006 the International Agency for Research on Cancer classified talcum powder as a possible human carcinogen if used in the female genital area. Yet no federal agency in the US acted to remove talcum powder from the market or add warnings. In February 2016, as the result of a lawsuit against Johnson & Johnson (J&J), a St. Louis jury awarded $72 million to the family of an Alabama woman who died from
ovarian cancer Ovarian cancer is a cancer that forms in or on an ovary. It results in abnormal cells (biology), cells that have the ability to invade or metastasis, spread to other parts of the body. When this process begins, there may be no or only vague sympto ...
. The family claimed that the use of talcum powder was responsible for her cancer. In May 2016, a South Dakota woman was awarded $55 million as the result of another lawsuit against J&J. The woman had used Johnson & Johnson's Baby Powder for more than 35 years before being diagnosed with ovarian cancer in 2011. In October 2016, a St. Louis jury awarded $70.1 million to a Californian woman with ovarian cancer who had used Johnson's Baby Powder for 45 years.Does baby powder cause cancer? Another jury thinks so, awarding $70 million to a California woman
''LA Times'' (2016-10-28). Retrieved on 2017-05-06.
In August 2017, a Los Angeles jury awarded $417 million to a Californian woman, Eva Echeverria, who developed ovarian cancer as a "proximate result of the unreasonably dangerous and defective nature of talcum powder", her lawsuit against Johnson & Johnson stated. On 20 October 2017, Los Angeles Superior Court judge Maren Nelson dismissed the verdict. The judge stated that Echeverria proved there is "an ongoing debate in the scientific and medical community about whether talc more probably than not causes ovarian cancer and thus (gives) rise to a duty to warn", but not enough to sustain the jury's imposition of liability against Johnson & Johnson stated, and concluded that Echeverria did not adequately establish that talc causes ovarian cancer. In July 2018, a court in St. Louis awarded a $4.7bn claim ($4.14bn in punitive damages and $550m in compensatory damages) against J&J to 22 claimant women, concluding that the company had suppressed evidence of
asbestos Asbestos (pronounced: or ) is a naturally occurring fibrous silicate mineral Silicate minerals are rock-forming mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fair ...
in its products for more than four decades. At least 1,200 to 2,000 other talcum powder-related lawsuits are pending.Woman wins $55M verdict against Johnson & Johnson in cancer suit
NY Daily News (3 May 2016)


See also

* * *


References

{{Authority control Phyllosilicates Magnesium minerals Symbols of Vermont Cosmetics chemicals Excipients IARC Group 3 carcinogens Clay minerals group Triclinic minerals Minerals in space group 2 Monoclinic minerals Minerals in space group 15 Luminescent minerals E-number additives