The Environmental Protection Agency is moving forward with a plan to sharply reduce and ultimately phase out experimental testing on lab animals. In an undated internal memo sent in late June to assistant administrators, EPA chief Andrew Wheeler explained that the agency will cut its funding for experiments on mammals in half by 2025. The memo, which was reviewed by The Intercept, also said that the EPA plans to stop using mammal studies for the approval of new chemicals by 2035 and that it will aim to eliminate all mammal studies. Under the new plan, any animal study done after that point will require approval by the EPA administrator.

The EPA is promoting alternative methods to gauge the threats posed by chemicals, such as computer modeling and tests on cells, which have been increasingly used in recent years. Yet no legal limits have ever been set using these alternative methods alone. Without the tests on rats, mice, and rabbits currently used to gauge the toxicity of chemicals and set safe levels, public health and environmental advocates worry that the policy shift will leave EPA unable to limit chemicals at all. “It effectively will mean you can’t regulate,” said Jennifer Sass, a senior scientist at the Natural Resources Defense Council.

The internal announcement that EPA would speed the move away from animal testing coincided with the creation of a new section on the agency’s website that was published last week. Titled “Alternative Test Methods and Strategies to Reduce Vertebrate Animal Testing,” the newly released material details the EPA’s efforts to “reduce and replace testing on vertebrates.” On March 14, Wheeler signaled that he would be making the shift in a speech, broadcast internally to EPA staff, in which he described the animal testing issue as “important to me personally.”

The chemical industry also appears to care deeply about the reduction of animal research, according to emails of EPA staff released in June in response to a Freedom of Information Act request. The American Chemistry Council, the largest American trade group representing chemical manufacturers, has long supported reducing regulators’ reliance on animal research, which is time-consuming and expensive — in addition to being key to understanding the harms chemicals pose to people.

The End of Chemical Regulation

A new generation of tests using cultured cells and computer simulation has expanded the ability to understand the risk compounds pose without using animals. Because it is not possible to perform animal tests for every one of the huge and growing number of man-made chemicals, these techniques, which can be done more quickly and cheaply, have become increasingly important.

But many scientists who study chemicals caution that research on cells outside a living organism, known as “in vitro toxicology,” cannot completely replace mammal experiments yet. “If you take the engine out of a car and study one piston at a time, it may not tell you what the car is going to do when you assemble it,” said Thomas Zoeller, a biologist at the University of Massachusetts Amherst who studies the health effects of man-made chemicals like polychlorinated biphenyls.

Zoeller’s own research revealed that, within mice, it’s not the actual PCB that causes harm but another chemical that the body creates by processing the original compound — a discovery that wouldn’t have been possible without exposing live mice to the chemical. “The parent compound gets into the animal and is metabolized in some tissues, including the brain. The body essentially bioactivates the parent compound,” Zoeller explained.

“If you exclusively depend on in vitro toxicology or mathematical modeling, you’re going to miss all the different interactions that happen in a physiological system — whether in rat, mouse, human, or a fetus. You simply cannot replicate that,” said Zoeller. “EPA is well aware that these cells don’t replicate human metabolism. So when it comes to bioactivation, they’re going to miss all that — and they know that.”

And that, some scientists fear, is exactly the reason the EPA is moving toward eliminating tests on animals. “If you require that, to regulate, you need to show an adverse affect for a chemical, and you can’t see an adverse affect in cells, then it’s to your benefit to only do testing in cells,” said Laura Vandenberg, a professor at UMass Amherst’s School of Public Health, who studies how exposures to chemicals during the development affects health later in life. “Laws, policy, and regulations require animal evidence.”

While regulatory rules can be updated to reflect new methods, it’s not clear how non-animal experiments would ever lead to restrictions. With animal tests, the presence of a clear endpoint such as cancer or birth defects helps regulators calculate safe levels for humans. But a positive finding in a non-animal test will likely only lead to more research, according to NRDC’s Sass.

“Let’s say they do find a hazard in a chemical. Let’s say it triggers changes associated with cancer. They don’t then call it a carcinogen. They just prioritize it for further testing,” said Sass, who has a PhD in anatomy and cell biology. “Then they test it on higher level tests, then on higher level tests. So if it is something that’s toxic, we’ll still go through years and years of testing and arguing and fighting.”

Now People Are the Guinea Pigs

In 2006, the EPA’s National Health and Environmental Effects Research Laboratory published a study showing that pregnant mice given the industrial chemical PFOA developed enlarged livers and had a greater chance of losing their pregnancies. The pups of the exposed mice weighed less and were developmentally delayed compared to the non-exposed pups, and the male pups had abnormal sexual development. While the EPA has yet to set a legal limit for PFOA, the agency used the mouse study to set a health advisory level for the chemical in 2009. And some states have used it to calculate their own regulations.

But since NHEERL did that groundbreaking work, the number of scientists leading animal research there has shrunken by more than half. The lab employed 56 principal investigators who conducted 139 active protocols involving animals in 2008, according to the EPA press office. This year, only 24 principal investigators were left, conducting 52 experiments involving lab animals. At another EPA lab focused on animal toxicology, the National Exposure Research Laboratory, the number of active protocols involving animals has dropped from 20 in 2008 to 13 in 2019. And neither lab will continue to exist after a planned reorganization of the Office of Research and Development is complete. Indeed, under the new structure, no labs that focus exclusively on animal research will remain. In his memo, Wheeler noted that 200,000 lab animals have already been spared from testing in recent years.

As Wheeler has embraced the adoption of new testing methods, the EPA has teamed up with animal rights groups such as PETA that oppose animal research because they see it as cruel. In April, the EPA co-sponsored a webinar on alternate methods of chemical assessment with PETA International Science Consortium and Physicians Committee for Responsible Medicine; the latter group is closely affiliated with the animal rights organization.

But it seems unlikely that the real issue for Wheeler, a former coal lobbyist reported to have invested in a burger restaurant, is animal welfare. Internal EPA communications point to the chemical industry’s interest in the alliance with animal rights groups. In a July 2017 email to representatives of Dow Chemical, Exxon Mobil, Syngenta AG, the American Chemistry Council, PETA International, and the EPA, Michael Dourson — Trump’s failed nominee to lead the EPA’s chemical safety division — proposed an Institute of Predictive Safety Assessment that would bring PETA together with the industry to help shift the thinking on testing, as E&E News reported that year.

The recently released batch of emails included one sent three months later to Nancy Beck, who then ran the EPA’s toxics office, and Dourson from Daland Juberg, who identified himself as heading human health science for DowDuPont. In it, Juberg inquired about the institute’s progress. “Let’s talk down the road on areas where EPA might have interest in moving the needle,” Juberg wrote.

While animal rights activists have focused on the ethics of exposing innocent creatures to toxic substances, by allowing chemicals onto the market without first testing their safety, people have essentially become the guinea pigs. Residents of Wilmington, North Carolina, may feel that particularly acutely. After the chemical GenX was discovered in the Cape Fear River downstream from a factory owned first by DuPont and now its spinoff, Chemours, researchers tested the blood of people who have been drinking the water and found four PFAS chemicals that had never been publicly identified, let alone studied.

“Do they have health effects? Which of the chemicals we found in their blood are related to high cholesterol? Which cause elevated liver enzymes?” asked Jane Hoppin, deputy director of the Center for Human Health and the Environment at North Carolina State University, which is conducting the blood study. “These poor people have been drinking these chemicals for 40 years, and we have nothing to offer them.”

With mysterious chemicals posing unknown harms within their own bodies, the people of Wilmington deserve more than cursory research, said Hoppin. “You can do a lot of quick testing in a petri dish,” she said. “But to see what really happens, you need a mammal.”

“Looking Forward to Collaborations!”

Beck, who directed regulatory science policy for the American Chemistry Council before Trump appointed her to run EPA’s toxics office in 2017, exchanged emails about the use of alternative techniques to replace animal testing with several chemical company representatives, including Dennis Deziel, director of federal government affairs for Dow Chemical.

“Dow is a leader in non-animal testing methods,” Deziel wrote to Beck in July 2017. “We want to engage on this issue in as helpful way as possible.” Beck met with Deziel and other Dow staff a few weeks later, according to the emails. “Extremely helpful for us,” Deziel wrote to Beck afterward.

Also at the meeting was Louis Scarano, an EPA toxicologist, who held at least one other meeting at which the issue was discussed with Deziel’s colleague, Sue Marty, Dow Chemical’s toxicology science director.

“I really appreciate your time and I enjoyed our conversation,” Marty wrote in an email to Scarano after that meeting, which was in mid-August 2017. “I think we share similar views on how alternate approaches could be used in the TSCA program,” she wrote, in a reference to the Toxic Substances Control Act, the primary federal law governing chemical regulation.

“Looking forward to collaborations!” the EPA’s Scarano responded. Scarano is now listed as the contact person for people seeking information on how the agency plans to reduce animal testing in TSCA as well as under other laws that involve chemical regulation.

Dow, it should be noted, is the maker of many chemicals that fall under the EPA’s purview and have been subject to animal testing, including chlorpyrifos, a pesticide linked to neurodevelopmental problems that the EPA found dangerous enough to ban in 2016; 1,3-butadiene, a chemical that a division of the EPA recently found — using animal testing — to cause cancer as well as reproductive and developmental problems; and ethylene oxide, another compound the EPA recently assessed. The EPA set the safety threshold for that chemical, which has caused elevated cancer risks in more than 50 places around the U.S., using studies showing ethylene oxide caused tumors of the brain, lung, connective tissue, uterus, and mammary glands of mice and rats.