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.

Researchers say the H5N1 bird flu outbreak in California elephant seals has spread to other marine mammals, including a sea otter and sea lion.

However, wildlife officials are cautiously optimistic the outbreak will remain contained. It has so far only been detected on beaches in San Mateo County, although testing is being conducted along the coastline.

The strain the animals have contains a mutation allowing it to more easily transmit between mammals. It is also a different variation than the ones found in dairy cows and commercial poultry. This one is Eurasian in origin, first seen in 2022. It has been detected in birds that fly along the Pacific Flyway, and is responsible for a mass mortality event in 2023 in northern fur seals on an island in eastern Russia, said Christine Johnson, director of UC Davis’ Center for Pandemic Insights, during a press conference Thursday morning.

Johnson said researchers think this is the first detection of the A3 variation of the virus on the Pacific Coast and therefore likely a new introduction into North America, she said.

In late February, a team of researchers from UC Davis, UC Santa Cruz, the California Department of Fish and Wildlife and the Marine Mammal Center announced they had found the virus in seven dead elephant seal pups collected from the beach at Año Nuevo State Park. That number is now 16, but Johnson said likely more will be confirmed in the weeks to come.

“This count reflects only the animals that have gone through sampling and confirmatory testing in multiple labs,” she said. “We know there are more animals with signs of infection that we have sampled that are being tested across the different laboratory systems.”

She said no other otters have been found, but a “handful” of California sea lions are “in the queue.” This kind of spillover, she said, is not unusual.

“Outbreaks affect a wide range of birds and mammals, and these animals all share the near shore ecosystem,” she said, although it’s “especially tragic” when infections affect less common species in the southern sea otter.

Patrick Robinson, the Año Nuevo reserve director, and a marine biologist at UC Santa Cruz, said 47 elephant seals on the mainland have died since the outbreak began, and the wildlife team is finding two new symptomatic and two dead animals every day.

Symptoms of bird flu in mammals include tremors, convulsions, seizures and muscle weakness.

He said it is normal for some individuals to die of natural causes, so testing is critical. And he said the percentage of animals that have died in the Año Nuevo rookery is relatively small: Only about 5% of weaned pups and 6% of adult males have died. Still, in the case of pups, that’s four times higher than last year’s death rates. And he said, the death of large males is “basically nonexistent in most males.”

He said 80% of the adult females had departed by the time the outbreak began, and nearly all of them are now gone. No adult females have died, and none have been observed with symptoms.

“The outbreak is not over, and we’re not really sure what’s going to happen in the future,” he said. “I remain hopeful about this thing right now.”

In late 2022, the H5N1 bird flu virus decimated southern elephant seal populations in South America and several sub-Antarctic Islands. At some colonies in Argentina, 97% of pups died, while on South Georgia Island, researchers reported a 47% decline in breeding females between 2022 and 2024. Researchers believe tens of thousands of animals died.

More than 30,000 sea lions in Peru and Chile died between 2022 and 2024. In Argentina, roughly 1,300 sea lions and fur seals perished.

At the time, researchers were not sure why northern Pacific populations were not infected, but suspected previous or milder strains of the virus conferred some immunity.

The virus is better known in the U.S. for sweeping through dairy herds, where it infected dozens of dairy workers, millions of cows and thousands of wild, feral and domestic mammals. It’s also been found in wild birds and killed millions of commercial chickens, geese and ducks.

Two Americans have died from the virus since 2024, and 71 have been infected. The vast majority of infected people were dairy or commercial poultry workers. One death was that of a Louisiana man who had underlying conditions and was believed to have been exposed via backyard poultry or wild birds.

A new report shows that nearly 40% of conventionally grown fruits and vegetables tested by California regulators have residues of “forever” or PFAS chemicals, a family of compounds that can be lasting and harmful.

The Environmental Working Group, an advocacy group based in Washington, D.C., reviewed California’s own test data and found PFAS pesticide residues on peaches, grapes and strawberries, and about three dozen other types of fruits and vegetables.

The chemicals have have increasingly been used in agricultural chemicals in recent years.

“Here’s the thing: This is an emerging threat,” said Nathan Donley, environmental health science director for the Center for Biological Diversity, who was not involved in the report. “PFAS pesticides went from being the exception to now they’re the rule.”

More than 90% of nectarine, peach and plum samples tested contained the PFAS fungicide fludioxonil. The fungicide is sprayed on the fruits after harvest to prevent mold. More than 80% of the cherries, strawberries and grapes sampled carried PFAS residue.

The group relied on data collected in 2023 by California’s Department of Pesticide Regulation, a branch of CalEPA.

There are thousands of PFAS chemicals used in consumer products, electronics, pharmaceuticals and pesticides. They are prized by product manufacturers for their strength, persistence and water resistance. However, many are considered highly toxic, even at very low levels. They’ve been linked to immune suppression, cancer and reproductive and developmental health disruptions and toxicity. They’ve also been linked to ecosystem damage, harming aquatic animals and wildlife.

The vast majority of PFAS chemicals have not been tested for human health effects.

“At a time when most industries are transitioning away from PFAS chemicals, the pesticide industry is actually doubling down on them,” said Donley, who has published papers on the issue. “I think that the persistence of these chemicals is certainly playing a role” in why industries find them desirable, he said.

“But then again, you get a whole heck of a lot more collateral damage when you have a pesticide that sticks around as long as DDT does,” he said.

Regulators say that not all PFAS chemicals are the same. While some can persist for thousands of years, others break down much more quickly. They also say the ones used in approved pesticides are vetted for human health impacts, as well as ecosystem impacts — such as how they could affect pollinators, aquatic organisms and other wildlife. There are also strict usage requirements that limit the amount of chemicals applied to food, they say.

“Before any pesticide can be sold or used in California, DPR (Department of Pesticide Regulation) conducts a thorough scientific review. This includes evaluating both the active ingredients and full product formulations to understand how long the chemicals remain in the environment and how they break down, which is a key concern for PFAS compounds,” said Amy MacPherson, a spokeswoman for the pesticide agency.

In addition, she said, while the report looks at “detections” of PFAS chemicals, her agency “looks at how those detections compare to federal tolerance levels.”

She said this is important because “detection alone … does not necessarily mean there’s a health risk. Tolerance levels consider lifelong, daily exposure that pose a reasonable certainty of no harm, inclusive of chronic risk.”

Varun Subramaniam, a co-author of the report and a health data specialist with the Environmental Working Group, said he focused on California for two reasons: California’s pesticide department is one of the few, if not only, state agencies to do this kind of testing; and the state is one of the nation’s largest producers of fruits and vegetables.

“Things that are grown in California tend to spread across the country,” said Subramaniam, who is working on a national report documenting the use of these pesticides. “We thought California was a good starting point.”

Roughly 70 PFAS pesticides are registered with the U.S. Environmental Protection Agency, accounting for about 14% of all active pesticide ingredients. California has registered 53 PFAS pesticides.

According to the report, about 2.5 million pounds of PFAS pesticides are applied annually on California cropland.

Both Subramaniam and Donley said states such as Maine, Rhode Island, Minnesota and North Carolina are “way ahead” of California in considering the harm these chemicals pose to people and ecosystems, and are trying to ban them.

“These chemicals are really top of mind in the East Coast, especially in New England states where … this story has been going on for decades,” he said.

Subramaniam said people should wash their produce before eating, and opt for organic fruits and vegetables when they can — organic farmers cannot use these chemicals on their produce.