Environmental Terms and Definitions

CERCLA
Comprehensive Environmental Response, Compensation and Liability Act. See "Superfund."

Exposure assessment
A process that estimates the amount of a chemical that enters or comes into contact with people or animals. An exposure assessment also describes how often and for how long an exposure occurred, and the nature and size of a population exposed to a chemical.

National Institute for Occupational Safety and Health (NIOSH)
NIOSH, part of the Centers for Disease Control, conducts research on worker safety and health and recommends standards for worker protection to OSHA. For example, NIOSH recommends guidelines for workplace exposure to hazardous substances and has published criteria documents on many chemicals.

World Health Organization (WHO)
WHO, an agency of the United Nations, carries out public and environmental health programs throughout the world.

Aquifer
An underground source of water. This water may be contained in a layer of rock, sand or gravel.

IDLH
Immediately dangerous to life and health. Used to determine selection of a respirator. The maximum concentration from which one could escape within 30 minutes without any escape-impairing symptoms or irreversible health effects. Also, IDLH conditions and conditions that would lead to an IDLH exposure.

Incineration
(1) burning of certain types of solid, liquid or gaseous materials. (2) a treatment technology involving destruction of waste by controlled burning at high temperatures, e.g., burning sludge to remove the water and reduce the remaining residues to a safe, non-burnable ash which can be disposed of safely on land, in some waters or in underground locations.

AHM
Acutely Hazardous Material

Material Safety Data Sheet (MSDS)
A compilation of information required under the OSHA Communication Standard on the identity of hazardous chemicals, health, and physical hazards, exposure limits, and precautions. Section 311 of SARA requires facilities to submit MSDSs under certain circumstances.

Preliminary Site Assessment (PSA)
A process followed by the NYS Department of Environmental Conservation (DEC) to determine if a site contains hazardous waste and its potential for harming the public health or environment.