Chemical & Exposure Guide

Hazard is not the same as exposure.

These profiles explain what documented contaminants can do, how exposure may occur, what is known about long-term effects, and where uncertainty remains. A chemical named at a site does not establish that a person, community, or wildlife population was exposed or harmed.

Hazard

What a substance is capable of causing under some conditions.

Detection

Where and when a laboratory measured a substance.

Exposure

Contact through air, water, food, soil, skin, or work.

Risk

Depends on dose, route, frequency, duration, and susceptibility.

Starting collection

23 priority profiles

23 of 23 profiles

Inorganic oxidizer salts

Perchlorate

Also known as Sodium perchlorate, Potassium perchlorate, Ammonium perchlorate

Perchlorate is an oxygen-containing ion found in several industrial salts. It has been used in flares, fireworks, propellants and other products; it can also occur naturally. It is chemically separate from phosgene and from PFAS.

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Chlorinated organic protective treatment

Impregnite CC-2

Also known as CC-2, CC2, XX-CC3, XXCC3

CC-2 was a reactive clothing treatment developed to protect against blister agents such as mustard. Army records describe its discovery in 1924, standardization in 1928, and wartime manufacture. It was a protective material, not evidence of finished poison-gas production at every plant that made it.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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