Hazard is not the same as exposure.

Per- and polyfluoroalkyl substances

PFAS

Also known as PFOA, C8, APFO, PFOS, PFNA, PFDA, PFHxS, PFBS, AFFF

PFAS are a large family of manufactured chemicals used in firefighting foams, fluoropolymer production, coatings, plating, textiles, paper, and many other applications.

Volatile organic compound

Benzene

Benzene is a volatile component of gasoline and petroleum and was also used in coke production, chemical manufacturing, solvents, and industrial processes.

Chlorinated solvent

Trichloroethylene

Also known as TCE

TCE was widely used to degrease metal parts and in other industrial cleaning and manufacturing operations.

Chlorinated solvent

Tetrachloroethylene

Also known as PCE, PERC, Perchloroethylene

PCE has been used extensively in dry cleaning, textile processing, metal degreasing, and industrial cleaning.

Volatile chlorinated compound

Vinyl chloride

Vinyl chloride is used to manufacture PVC and can also form underground when TCE, PCE, and related solvents break down.

Persistent chlorinated compounds

PCBs

Also known as Polychlorinated biphenyls

PCBs were used in electrical equipment, hydraulic systems, heat-transfer fluids, building materials, and industrial processes before most U.S. uses were banned.

Combustion and coal-tar compounds

PAHs

Also known as Polycyclic aromatic hydrocarbons

PAHs form during incomplete combustion and occur in coal tar, coke-oven waste, creosote, petroleum, soot, and contaminated sediment.

Persistent chlorinated byproducts

Dioxins

Also known as Chlorinated dioxins, CDDs

Dioxins can form as unwanted byproducts of combustion and certain chlorine-based industrial processes.

Toxic metal

Lead

Lead has been used in paint, batteries, metalworking, fuels, plumbing, pigments, ammunition, and many industrial products.

Metalloid

Arsenic

Arsenic occurs naturally and has also been used in pesticides, wood treatment, metal production, pigments, and industrial processes.

Toxic metal

Mercury

Also known as Methylmercury

Mercury has been used in industrial equipment and chemical production and can also enter the environment through combustion and atmospheric deposition.

Toxic metal

Cadmium

Cadmium has been used in batteries, pigments, plating, alloys, plastics, and metal production.

Metal with multiple chemical forms

Chromium

Also known as Hexavalent chromium, Chromium VI

Chromium compounds are used in plating, pigments, leather tanning, corrosion control, alloys, and refractory materials.

Reactive chemical group

Cyanide

Cyanide compounds have been used in metal finishing, electroplating, coke production, mining, and chemical manufacturing.

Volatile sulfur compound

Carbon disulfide

Also known as CS2

Carbon disulfide has been used to manufacture rayon, cellophane, rubber chemicals, and sponge or cellulose products.

Emerging solvent contaminant

1,4-Dioxane

1,4-Dioxane has been used as a solvent stabilizer and in manufacturing and may occur with chlorinated-solvent contamination.

Organochlorine pesticide

DDT

Also known as DDD, DDE

DDT was widely used as an insecticide. DDE and DDD are persistent breakdown products commonly included in environmental investigations.

Fibrous mineral hazard

Asbestos

Asbestos was used in insulation, fireproofing, cement, roofing, flooring, brakes, gaskets, and many industrial buildings and products.

Radioactive metal

Uranium

Also known as Depleted uranium

Uranium occurs naturally and has been mined, refined, processed, and used in nuclear fuel and military or industrial applications.

Radioactive alkaline-earth metal

Radium

Also known as Ra-226, Ra-228

Radium occurs naturally in uranium and thorium decay chains and has historical industrial, medical, and luminous-paint uses.