Glossary of Terms

Term Definition
Chemical Abstracts Service (CAS) Number Unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. They are also referred to as CAS registry numbers, CAS RNs or CAS #s. In the TRI Explorer reports, these numbers are presented without hyphens.
Core Chemicals A group of chemicals that have been consistently reported to TRI in every year since the year denoted on the list. Core chemical groups account for changes made to the list of TRI reportable chemicals between reporting years.
Form Types North American Industry Classification System Facilities report chemicals to TRI using one of two form types: the Form R or the Form A. The Form R is the reporting form that must be annually submitted by the owner or operator of a covered facility. The Form A is a simplified form which may be used in place of the Form R by facilities with low quantities of listed toxic chemicals in waste. The Form A became available as a burden-reducing option in 1995, when TRI’s chemical and industry coverage expanded.
Hazardous Air Pollutants (HAPs) HAPs, also known as toxic air pollutants, are those pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects.
North American Industry Classification System (NAICS) Codes A standard set of codes used to classify business establishments into industry sectors.
Newly Added 1995 Chemicals The 286 chemicals that were added to the list of TRI reportable chemicals for the 1995 reporting year. These chemicals were added because they cause short, acute human health risks.
Occupational Health & Safety Administration (OSHA) Carcinogens Cancer-causing agents identified by the Occupational Health & Safety Administration.
Persistent, Bioaccumulative, and Toxic (PBT) Chemicals Long-lasting substances that can build up in the food chain to levels that are harmful to human and ecosystem health.
Public Data Release (PDR) The TRI program releases TRI data to the public annually in a Public Data Release (PDR). PDR data are frozen on the date of the release, and do not include revisions or withdrawals made to TRI data after the PDR date.