Toxic substances are chemicals or compounds that may present an unreasonable threat to human health and the environment. Human exposure to toxic substances can cause a variety of health effects, including damage to the nervous system, reproductive and developmental problems, cancer, and genetic disorders. EPA's goal is to identify and reduce the risks from toxic substances. As part of its regulation of these substances, the Agency conducts risk assessments, compiles databases of toxic releases and provides information on their safe handling and disposal. To achieve this goal, the Agency employs an increasingly holistic approach that spans the boundaries of media, programs and geography.

Recommended EPA Web pages

• New Chemicals Program
  The New Chemicals Program was established to help manage the potential risk from chemicals new to the marketplace.
• Summary of the Toxic Substances Control Act
  TSCA of 1976 was enacted by Congress to give EPA the ability to track the 75,000 industrial chemicals currently produced or imported into the United States.
• Substance Registry Services
  The Substance Registry System provides information on substances and how they are represented in EPA regulations and information systems.

Air Pollutants
Aerosols, Asbestos, Carbon Monoxide, Chlorofluorocarbons (CFCs), Criteria Air Pollutants, Ground Level Ozone, Hazardous Air Pollutants (HAPs), Hydrochlorofluorocarbons (HCFCs), Lead, Mercury, Methane, Nitrogen Oxides (NOx), Particulate Matter (PM), Propellants, Radon, Refrigerants, Sulfur Oxides (SOx), Volatile Organic Compounds (VOCs)

Biological Contaminants

Carcinogens

Chemicals
Benzene, Chlorofluorocarbons (CFCs), Chromated Copper Arsenate (CCA), Dichloroethylene (DCE), Dioxins, Endocrine Disruptors, Ether, Ethylbenzene, Furans, Halons, Hazardous Air Pollutants (HAPs), Heavy Metals, Hydrochlorofluorocarbons (HCFCs), Inorganic Cyanides, Ketones, Methane, Methyl Bromide, Methyl Chloride, Methyl-T-Butyl-Ether (MTBE), Nitrogen Oxides (NOx), Organic Cyanides, Particulate Matter (PM), Perchloroethylene (PCE), Phthalates, Polychlorinated Biphenyls (PCBs), Radionuclides, Styrene, Sulfur Hexafluoride (SF6), Sulfur Oxides (SOx), Toluene, Trichloroethylene (TCE), Volatile Organic Compounds (VOCs)

Microorganisms
Coliform, Cryptosporidium, Viruses

Ozone

Radiation
Ionizing Radiation, Radiation Detection, Radiation Exposure, Radiation Protection, Radionuclides, Radon

Soil Contaminants
Acetone, Arsenic, Barium, Benzene, Cadmium, Chloroform, Cyanide, Lead, Mercury, Polychlorinated Biphenyls (PCBs), Tetrachloroethylene, Toluene, Trichloroethylene (TCE)

Toxic Substances
Persistent Bioaccumulative Toxic Pollutants (PBTs), Persistent Organic Pollutants (POPs), Toxicological Profiles

Water Pollutants
Arsenic, Contaminated Sediment, Disinfection Byproducts, Dredged Material, Lead, Microbial Pathogens