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Toxics Release Inventory

Toxics Release Inventory (TRI) reports are required under the Emergency Planning and Community Right-to-Know Act (EPCRA).  The TRI data identifies chemicals manufactured and used at certain businesses or facilities. It tracks accidental and routine releases of those chemicals to air, land, and water and how waste is managed or disposed.  

The EPA compiles the national TRI data each year and makes the information available through several data access tools.

What is a release?

Releases in TRI are classified as either "on-site" or "off-site."

On-site release: The amount of a toxic chemical a facility emits or disposes to air, water, or land.

Off-site release: The amount transferred off site for disposal; it also includes metals released into wastewater that goes to a publicly owned treatment works (POTW).

How is this data used?

TRI is used to better understand:

  • Potential risks from chemical releases
  • Improve safety
  • Protect the environment

Environmental justice

National and regional environmental justice studies, including the Environmental Equity Study In Washington State, have used TRI data to demonstrate a pattern of low-income communities and people of color living disproportionately near industrial facilities.

For information about Ecology’s work regarding environmental justice and its relationship to TRI, contact Millie Piazza at 360-407-6177.

TRI data over time

The data serve as an indicator of environmental progress over time. Federal, state, and local governments have used TRI to set priorities, measure progress, and target areas of special and immediate concern. For example, TRI data are used to measure pollution trends from specific industries. It shows trends of whether industrial pollution is going up or down and helps identify whether reduction targets are being met.

TRI is one indicator used in the Washington Beyond Waste and Toxics Progress Report to track progress toward reducing wastes and toxics.

Large releases at Pend Oreille Mine has significant impact on Washington's total TRI numbers. The Pend Oreille Mine reported large amounts of land releases from 2004 to 2009. As production at the mine decreased, so did Washington's total land releases. The mine stopped operating in early 2009, but reopened in December 2014. TRI releases from the mine have increased each year since 2014 as production from the mine has increased. The mine released 14.8 million pounds of TRI chemicals (mostly zinc compounds) in 2016, nearly half (48.9 percent) of Washington's 30.2 million-pound total.


TRI data does not show if or to what degree the public is exposed to listed chemicals. Exposure to a chemical depends on many factors that fall outside of the scope of TRI data.

Toxicity Not all toxics are reported