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EPA Opens Public Comment Period on Cuprous Iodide Draft Ecological Risk Assessment

For Release: August 13, 2020

The U.S. Environmental Protection Agency (EPA) is accepting comments on its determination that cuprous iodide, when used in a materials preservative embedded in specific fibers, plastics and films, is not expected to pose a discernable threat to terrestrial and aquatic organisms.

Cuprous iodide is an active ingredient in the material preservative Cupron Cuprous Iodide Masterbatch, a material preservative that suppresses the growth of algae, mold, mildew, fungi and bacteria from manufactured products such as bedding, carpets, floor coverings, upholstery, shoes, gloves, sails and awnings.

This determination is in response to a 2019 lawsuit filed by the Center of Biological Diversity (CBD) alleging that EPA violated the Endangered Species Act (ESA). CBD expressed concern that Cupron Cuprous Iodide Masterbatch could jeopardize threatened and endangered species and their habitats.

To address these issues, Cupron submitted a label amendment that removed the use of cuprous iodide in frequently washed material goods. The remaining uses include certain fibers, plastics and films not expected to create down-the-drain discharge. After assessing the label amendments and completing a draft ecological risk assessment, EPA does not anticipate unreasonable adverse effects from the revised use of cuprous iodide.

Comments are accepted in docket EPA-HQ-OPP-2013-0433 at for 30 days, closing on Sept. 14, 2020.