The Trump administration on Friday moved to roll back Biden-era limits on emissions of ethylene oxide, a cancer-causing chemical often used in the sterilization of medical devices.

The Environmental Protection Agency said repealing the rules, which fall under the National Emission Standards for Hazardous Air Pollutants, would “safeguard the supply of essential medical equipment” — saving approximately $630 million for companies over 20 years. California is home to about a dozen such facilities.

The government said the pollution is an inevitable part of protecting people from “lethal or significantly debilitating infections that would result without properly sterilized medical equipment,” arguing that the technology does not readily exist to meet the more stringent rules.

“The Trump EPA is committed to ensuring life-saving medical devices remain available for the critical care of America’s children, elderly, and all patients without unnecessary exposure to communities,” EPA Administrator Lee Zeldin said in a statement.

Supporters of the Biden rule reject that argument and say companies could have complied using existing technology and that the public was not at risk of losing sterilized equipment.

An estimated 50% of sterile medical devices in the U.S. are treated with ethylene oxide, or EtO, particularly those that can’t be cleaned using steam or radiation. The colorless gas is also used to make chemicals found in products such as antifreeze, detergents, plastics and adhesives.

EtO poses health risks. Short-term exposure by inhalation can cause headaches, dizziness, nausea, fatigue respiratory irritation and other adverse health effects, according to the federal Agency for Toxic Substances and Disease Registry.

Longer-term exposure increases the risk of cancers of the white blood cells, such as non-Hodgkin’s lymphoma, as well as breast cancer. A now-deleted page from the EPA’s website stated, “EtO is a human carcinogen. It causes cancer in humans.”

Friday’s proposal specifically targets updated rules for EtO emissions that were passed by the Biden administration in 2024 following pressure from environmental justice groups, particularly those in Louisiana’s heavily industrialized “Cancer Alley.” The change sought to reduce the amount of EtO released from commercial sterilizers by 90% and lessen the hazards for nearby communities.

The tighter rules were in part based on EPA’s own scientific study that found it to be 60 times more carcinogenic than previously thought, which the agency now says should be reassessed.

If finalized, the plan would give facilities a choice between installing continuous real-time monitoring systems for EtO emissions or complying with modified pollution control requirements at facilities that emit more than 10 tons a year, the EPA said.

The proposal follows other moves by the Trump administration to rescind regulations it says are burdensome and costly for industries, such as those governing emissions from coal power plants. Last month, the EPA repealed the endangerment finding, which affirmed the dangers of greenhouse gas emissions and underpinned the agency’s ability to regulate those emissions from vehicles.

The action around ethylene oxide would affect about 90 commercial sterilization facilities owned and operated by approximately 50 companies. Three California companies applied for and received presidential exemptions for their EtO emissions in July.

They are located in Ontario and Vernon and operated by the company Sterigenics, which provides industrial sterilization technology for medical devices and other commercial products.

In January, a coalition of environmental and community groups challenged the EtO exemptions in federal court. The lawsuit from the Southern Environmental Law Center and the Natural Resources Defense Council argues that technology exists for facilities to comply with the tighter Biden-era standards without raising costs, and many facilities are already using it.

“EPA’s 2024 rule was an important and overdue step to reduce toxic ethylene oxide pollution and protect communities,” said Irena Como, senior attorney at the Southern Environmental Law Center, in a statement Friday. “Repealing this rule that is proven to significantly lower pollution exposure and cancer risks will subject even more people who work, live, and send their children to schools located near these facilities to harm that is entirely preventable.”

Sterilization and chemical industry groups support the plan.

“The EPA rule concerning ethylene oxide use in commercial sterilizers threatens to severely restrict access to vital medical products nationwide,” the American Chemistry Council said in a statement. “We commend the EPA for their commitment to reevaluating these policies.”

The EPA will hold a 45-day comment period about the proposal after it is published in the federal register. A final decision is expected sometime this year.