Environmental Protection Agency
Text Version of TRI Explorer Additional Resources

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Acronym Stands for...
CAS Chemical Abstracts Service Number
HAPs Hazardous Air Pollutants
NAICS North American Industry Classification System
OSHA Occupational Health & Safety Administration
PBT Persistent, Bioaccumulative, and Toxic chemicals
PDR Public Data Release
TRI Toxics Release Inventory

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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.

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Useful Links
Topic Source Description
About Air Toxics EPA Presents frequently asked questions concerning hazardous air pollutants (HAPs).
Changes To The TRI List Of Toxic Chemicals EPA Contains a list of deletions and modifications to the list of TRI chemicals.
Emergency Planning and Community Right-to-Know Act Overview EPA EPA’s EPCRA home page.
Hazard Information on Toxic Chemicals Added to EPCRA Section 313 Under Chemical Expansion EPA Provides summary hazard information on the 286 chemicals that were added to the Toxics Release Inventory in 1994.
Integrated Risk Information System (IRIS) EPA An electronic database containing information on human health effects that may result from exposure to various substances in the environment. IRIS may be used to learn more about specific TRI reported chemicals.
Metals and Metal Compounds EPA Lists the TRI reportable metals and metal compounds.
North American Industry Classification System (NAICS) U.S. Census Bureau Provides an overview of NAICS and the industry sector definitions for each NAICS code.
OSHA Carcinogens EPA Information on OSHA carcinogens applicable to TRI.
Persistent Bioaccumulative and Toxic (PBT) Chemical Program: Frequently Asked Questions EPA Presents answers to frequently asked questions concerning PBT chemicals.
Pollution Prevention Act of 1990 EPA EPA’s Pollution Prevention Act home page.
ToxFAQs Agency for Toxic Substances & Disease Registry A series of summaries about hazardous substances developed by the ATSDR Division of Toxicology. Information for this series is excerpted from the ATSDR Toxicological Profiles and Public Health Statements. Each fact sheet serves as a quick and easy to understand guide. Answers are provided to the most frequently asked questions (FAQs) about exposure to hazardous substances found around hazardous waste sites and the effects of exposure on human health. ToxFAQs may be used to learn more about specific TRI reported chemicals.
Toxics Release Inventory Program EPA Provides an overview of the TRI program, ways to access TRI data, reporting materials, reportable chemicals, laws and regulations, and similar state and international programs.

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