U.S. EPA updates aquatic life benchmarks for registered pesticides and antimicrobial chemicals

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. These benchmarks are estimates of the concentrations below which pesticides (including conventional pesticides and antimicrobial chemicals) are not expected to present a risk of concern for freshwater organisms.

The updated Aquatic Life Benchmarks represent 759 chemicals (parent compounds or degradates) including newly registered pesticides or new values for previously registered pesticides and selected degradates. The updates include: 

• Benchmarks for 27 new chemicals (i.e., 16 new active ingredients and 11 of their degradates).

• Additional benchmarks for 10 degradates of chemicals with existing benchmarks. 

• Revised benchmarks for 72 existing chemicals (i.e., 57 registration review chemicals and 15 degradates).  

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

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

This update supersedes the previous version published Aug. 31, 2021. EPA intends to continue updating these benchmarks yearly. 

Read the summary of updated benchmarks or see the complete Aquatic Life Benchmarks table.