Washington, DC — More than 20 states have taken action to remove persistent, toxic per- and polyfluoroalkyl substances (PFAS) from the environment, and Colorado should join this effort by regulating pesticides sprayed in the state, according to a coalition of state legislators and public health groups led by Public Employees for Environmental Responsibility (PEER). New studies show high levels of PFASs, toxic man-made chemicals which do not break down in the environment and bioaccumulate in humans, are found in pesticides applied in Colorado.

In July 2024, the federal government approved Indaziflam, a pre-emergent herbicide designed to prevent seed germination and control invasive annual grasses, for use on public lands. Tests show that this herbicide contains high levels of PFAS. Nonetheless, the U.S. Bureau of Land Management and Forest Service are spraying this agent across millions of acres of public land, including federal and state lands in Colorado.

A growing body of scientific evidence indicates that Indaziflam is harmful to human health, soil, ecosystems, native biodiversity, wildlife, and aquatic systems. Its product label also warns that it can contaminate surface waters via runoff and is toxic to fish, vertebrates, and aquatic plants.

Despite federal approval, states can take their own protective measures against PFAS pollution. 24 states are either outlawing or phasing out products containing PFAS.

The coalition letter calls on Governor Jared Polis to take three steps:

• Direct Colorado’s Department of Agriculture to require that pesticide manufacturers test every registered product and certify to the state that the product does not contain PFAS;
• Immediately cease applying pesticides containing PFAS on state lands; and
• Support a ban on the use of any pesticide containing any form or amount of PFAS.

“Colorado needs to act now to protect its streams and wetlands from further pollution by forever chemicals that poison our food chain,” stated PEER Public Lands Advocate Chandra Rosenthal, noting that under President Trump, the U.S. Environmental Protection Agency (EPA), has halted progress in stopping the spread of PFAS. “Colorado must step up and defend its own lands and waters because there is no more federal backstop.”

The legislators joining the PEER letter to Gov. Polis are State Senator Lisa Cutter as well as Representatives Lorena Garcia, Sheila Lieder, and Kenny Van Nguyen. Organizations signing on are the People & Pollinators Action Network, Colorado Sierra Club, Conservation Colorado, Colorado Environmental Health Coalition, Fountain Valley Clean Water Coalition, Ecological Consultants, and the Society for the Protection of Insects.

“Indaziflam was marketed to land managers as a tool for restoring Colorado’s open spaces, but we now know it contains PFAS, forever chemicals that accumulate in our soils, waterways, and bodies, making it even more problematic,” said Joyce Kennedy, executive director of the People and Pollinators Action Network. “If we’re contaminating our precious open spaces, this isn’t restoration.”

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Read the coalition letter 

See PEER’s 2022 letter to Gov. Polis

Look at PFAS testing results

Note EPA’s abdication of PFAS control

See the 2024 peer-reveiwed report on PFAS in pesticides

PEER protects public employees who protect our environment, natural resources, and public health. We support current and former environmental and public health professionals, land managers, scientists, enforcement officers, and other civil servants dedicated to upholding environmental laws and values across federal, state, local, and tribal governments.