Environmental Terms and Definitions

HMTUSA
Hazardous Materials Transportation Uniform Safety Act (1999); amendments to HMTA including requirements for performance-oriented packaging.

Interim Remedial Measure (IRM)
An action taken at a contaminated site to reduce the chances of human or environmental exposure to site contaminants. Interim remedial measures are planned and carried out before comprehensive remedial studies.

Consumer Product Safety Commission (CPSC)
The CPSC, a federal commission, protects the public from injury caused by consumer products. The CPSC evaluates products, investigates the causes of product-related injuries and issues and enforces safety standards

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

Biological monitoring
Analyzing chemicals, hormone levels or other substances in biological materials (blood, urine, breath, etc.) as a measure of chemical exposure, health status, etc. in humans or animals. A blood test for lead is an example of biological monitoring.

acute health effect
Health effects that usually occur rapidly as a result of short-term exposures, and are of short duration. Some examples are irritation, corrosivity (tissue destruction), narcosis, and death

Exposure
Contact with a chemical by swallowing, by breathing or by direct contact (such as through the skin or eyes). Exposure may be either short term (acute) or long term (chronic).

Analyte
A chemical for which a sample (such as water, air, blood, urine or other substance) is tested. For example, if the analyte is mercury, the laboratory test will determine the amount of mercury in the sample.

Route of exposure
The way in which a person may contact a chemical substance. For example, drinking (ingestion) and bathing (skin contact) are two different routes of exposure to contaminants that may be found in water. See "Exposure".

Agency for Toxic Substances and Disease Registry (ATSDR)
ATSDR is part of the U.S. Department of Health and Human Services. As mandated by the federal superfund law, the agency assesses health risks from hazardous waste sites on the National Priority List.