fresh water stream

Aquatic Life Benchmarks for Registered Pesticides

This original announcement was published by the EPA on August 31, 2021. Click here for more information.


The U.S. Environmental Protection Agency (EPA), in collaboration with the California Department of Pesticide Regulation and the U.S. Geological Survey, has released an updated version of the Aquatic Life Benchmarks. Aquatic Life Benchmarks are estimates of the concentrations below which pesticides are not expected to present a risk of concern for freshwater organisms.

The updated Aquatic Life Benchmarks represent newly registered pesticides or new values for previously registered pesticides and selected degradates. This is the first update to include benchmarks for 18 additional antimicrobial chemicals. While antimicrobial chemicals have been included as benchmarks in the past when they have dual uses as conventional pesticides, recently there has been an increased interest in a broader array of antimicrobial compounds due to their use against COVID-19.

EPA based these benchmarks on toxicity values from scientific studies that the agency has reviewed and has used in publicly accessible ecological risk assessments in support of regulatory decisions for pesticides. For each of the chemicals listed, the table provides a link to the source documents from which each of the benchmarks is extracted.

Comparing a measured concentration of a pesticide in water to Aquatic Life Benchmarks can be helpful in interpreting monitoring data and in identifying and prioritizing monitoring sites that may require further investigation. State, tribal, and local governments use these benchmarks in their interpretation of water monitoring data. International regulatory authorities and researchers also use these data in their work.

EPA’s goal is to add to these benchmarks on an annual basis; the last update was published September 28, 2020.