U.S. Rep. Ed Perlmutter introduced legislation on Thursday to study the use of certain hazardous chemicals in firefighting equipment that are associated with cancer and adverse effects on the immune system.

The Guaranteeing Equipment Safety for Firefighters Act is aimed at per- and polyfluoroalkyl substances, known as PFAS. The proposal would direct the National Institute of Standards and Technology to study how the chemicals may be released into the environment during firefighting and the exposure risk to first responders. PFAS have been used in firefighting foam and for making gear water-resistant.

A companion bill in the U.S. Senate passed out of committee in November. U.S. Sens. Cory Gardner and Jeanne Shaheen, D-N.H., are the sponsors of that measure.

“In order to reduce the serious risk to our firefighters, we must first understand the means and the frequency at which firefighters are being exposed to these dangerous chemicals,” said Perlmutter. “These brave men and women put their lives on the line every day for our communities and we must do everything we can to protect them in return.”

A study published in June suggests that because PFAS shed from the textiles in firefighting gear and become mobile, there should be further research about potential exposure and corresponding health risks. The federal government has not yet mandated maximum PFAS levels, and has only issued an advisory threshold for PFAS in drinking water.

Last month, Gov. Jared Polis signed a bill into law that regulates the capture and disposal of PFAS chemicals by fire departments and other facilities in Colorado.