[ To reduce the accumulation and ultimately clear out these stacks, research is underway to find more applications for such waste products.]
People can be exposed to gypsum in the workplace by breathing it in, skin contact, and eye contact. Calcium sulfate ''per se'' is nontoxic and is even approved as a food additive,
but as powdered gypsum, it can irritate skin and mucous membranes.
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 legal 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 ...) for gypsum exposure in the workplace as TWA 15 mg/m3 for total exposure and TWA 5 mg/m3 for respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of TWA 10 mg/m3 for total exposure and TWA 5 mg/m3 for respiratory exposure over an 8-hour workday.
Gypsum is used in a wide variety of applications:
* Gypsum board is primarily used as a finish for walls and ceilings, and is known in construction as plasterboard, "sheetrock", or drywall. Gypsum provides a degree of fire-resistance to these materials and glass fibers are added to their composition to accentuate this effect. Gypsum has little heat conductivity, giving its plaster some insulative properties.
* Gypsum blocks are used like concrete blocks in building construction.
* Gypsum mortar is an ancient mortar used in building construction.
*A component of Portland cement
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19th ce ... used to prevent flash setting (too rapid hardening) of concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ....
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 ...: In the late 18th and early 19th centuries, Nova Scotia gypsum, often referred to as plaster, was a highly sought fertilizer for wheat fields in the United States. Gypsum provides two of the secondary plant macronutrients, calcium and sulfur. Unlike limestone, it generally does not affect soil pH.
* Reclamation of saline soils, regardless of pH. When gypsum is added to sodic (saline) and acidic soil
Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the ne ..., the highly soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solu ... form of boron
Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the '' boron group'' it has t ... ( sodium metaborate
Sodium metaborate is a chemical compound of sodium, boron, and oxygen with formula . However, the metaborate ion is trimeric in the anhydrous solid, therefore a more correct formula is or . The formula can be written also as · to highlight the ...) is converted to the less soluble calcium metaborate. Exchangeable sodium percentage is also reduced by gypsum application. The Zuiderzee Works uses gypsum for the recovered land.
*Other soil conditioner
A soil conditioner is a product which is added to soil to improve the soil’s physical qualities, usually its fertility (ability to provide nutrition for plants) and sometimes its mechanics. In general usage, the term "soil conditioner" is often ... uses: Gypsum reduces aluminium and boron toxicity in acidic soils. It also improves soil structure, improving water absorption and aeration.
*A wood substitute in the ancient world: For example, when wood became scarce due to deforestation on Bronze Age
The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second p ... Crete
Crete ( el, Κρήτη, translit=, Modern: , Ancient: ) is the largest and most populous of the Greek islands, the 88th largest island in the world and the fifth largest island in the Mediterranean Sea, after Sicily, Sardinia, Cyprus, an ..., gypsum was employed in building construction at locations where wood was previously used.
*Soil water potential
Water potential is the potential energy of water per unit volume relative to pure water in reference conditions. Water potential quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure and matr ... monitoring: a gypsum block can be inserted into soil, its electrical resistance measured to derive soil moisture.
Modeling, sculpture and art
* Plaster for casting moulds and modeling.
*As alabaster, a material for sculpture, it was used especially in the ancient world before steel was developed, when its relative softness made it much easier to carve. During the
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ... and Renaissance
The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass idea ..., it was preferred even to marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorphose ....
*In the medieval period, scribe
A scribe is a person who serves as a professional copyist, especially one who made copies of manuscripts before the invention of automatic printing.
The profession of the scribe, previously widespread across cultures, lost most of its promin ...s and illuminators used it as an ingredient in gesso, which was applied to illuminated letters and gilded with gold in illuminated manuscripts.
Food and drink
Tofu (), also known as bean curd in English, is a food prepared by coagulating soy milk and then pressing the resulting curds into solid white blocks of varying softness; it can be ''silken'', ''soft'', ''firm'', ''extra firm'' or ''super fir ... (soy bean curd) coagulant, making it ultimately a significant source of dietary calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ....
In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard ... to water used for brewing
Brewing is the production of beer by steeping a starch source (commonly cereal grains, the most popular of which is barley) in water and fermenting the resulting sweet liquid with yeast. It may be done in a brewery by a commercial brewer, ....
*Used in baking as a dough conditioner, reducing stickiness, and as a baked-goods source of dietary calcium. The primary component of mineral yeast food.
*Used in mushroom cultivation to stop grains from clumping together.
Medicine and cosmetics
* Plaster for surgical splints.
*Impression plasters in dentistry.
*An alternative to iron oxide in some thermite mixes.
*Tests have shown that gypsum can be used to remove pollutants such as
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 cut, l ... or arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ... [
] from contaminated waters.
File:Gypsum-71006.jpg, Green gypsum crystals from Pernatty Lagoon, Mt Gunson,
South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territori ... - its green color is due to presence of copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish- ... ions.
File:Gypsum-162462.jpg, Unusual selenite gypsum from the Red River, Winnipeg, Manitoba, Canada
File:Gypsum-47190.jpg, Classic "ram's horn" gypsum from Santa Eulalia, Chihuahua, Mexico, 7.5×4.3×3.8 cm
File:Roses des Sables Tunisie.jpg, Desert rose, 47 cm long
File:Gypsum-53691.jpg, Gypsum from Pernatty Lagoon, Mt Gunson, Stuart Shelf area, Andamooka Ranges - Lake Torrens area, South Australia, Australia
File:Copper-Gypsum-203925.jpg, Gypsum with crystalline native copper
Native copper is an uncombined form of copper that occurs as a natural mineral. Copper is one of the few metallic elements to occur in native form, although it most commonly occurs in oxidized states and mixed with other elements. Native cop ... inside
File:Gypsum J1.jpg, Gypsum from Swan Hill, Victoria, Australia. The coloring is due to the copper oxide
File:Gypsum-21996.jpg, Waterclear twined crystal of the form known as "Roman sword". Fuentes de Ebro, Zaragoza (Spain)
File:Botryogen-Gypsum-199664.jpg, Bright, cherry-red gypsum crystals 2.5 cm in height colored by rich inclusions of the rare mineral botryogen
File:Gypse Naica.jpg, Gypsum from Naica, Mun. de Saucillo, Chihuahua, Mexico
File:Gypsum-251118.jpg, Golden color gem, "fishtail"-twinned crystals of gypsum sitting atop a "ball" of gypsum which is composed of several single bladed crystals
* Gypsum flora of Nova Scotia
* Gypsum recycling
Minerals in space group 15