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TRI National Analysis

Chemicals of Special Concern

In this section, we take a closer look at some Toxics Release Inventory (TRI) chemicals that are of special concern: 1) persistent, bioaccumulative, and toxic (PBT) chemicals; and 2) known or suspected human carcinogens.

Chemicals designated as PBTs are toxic and remain in the environment for a long time where they tend to build up in the tissue of organisms throughout the food web. These organisms serve as food sources for other organisms, including humans, that are sensitive to the toxic effects of PBT chemicals.

Reporting requirements for the 16 chemicals and 5 chemical categories designated as PBTs on the TRI chemical list for Reporting Year 2017 are more stringent than for other TRI chemicals. This section focuses on the following PBT chemicals: lead and lead compounds; mercury and mercury compounds; and dioxin and dioxin-like compounds.

There are also chemicals included on the TRI chemical list that the Occupational Safety and Health Administration (OSHA) includes on its list of carcinogens. These chemicals also have different TRI reporting requirements. This section presents the trend in air emissions for the OSHA carcinogens reported to TRI. A list of these chemicals can be found on the TRI basis of OSHA carcinogens webpage.


This page was published in March 2019 and uses the 2017 TRI National Analysis dataset made public in TRI Explorer in October 2018.

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