A chemical produced in a Louisiana plant is the subject of a challenge to a US government chemical-safety programme.Credit: William Widmer/Redux/eyevine

The US Environmental Protection Agency is making major changes to the way in which it evaluates chemicals for environmental and public-health effects. The latest push includes changes to chemical-safety guidelines that place greater weight on industry-sponsored research, among other things, and is a part of efforts by US President Donald Trump’s administration to reshape how the agency uses science to make decisions.

The Environmental Protection Agency (EPA) issued its chemical-assessment guidance in May, and is soliciting public comments until 16 August. The guidance contains changes dictating the kind of data that studies must include in order to be considered in the EPA’s decision-making process. Researchers and environmental and public-health advocates say that the guidelines provide a non-peer-reviewed alternative to the EPA’s main system for conducting chemical reviews and calculating acceptable exposure limits. The agency is required by law to do these evaluations, but the guidance defines how officials conduct them. At stake are tens of thousands of chemicals destined for public use and governed by the 1976 Toxic Substances Control Act (TSCA).

The guidance dovetails with a rule proposed in April by then-EPA administrator Scott Pruitt, which, if finalized and implemented, would reduce the role of published scientific studies in decision-making across the agency. The changes also coincide with attacks on the EPA’s core chemical-assessment programme, known as the Integrated Risk Information System (IRIS), by industry and Republican politicians over the past year.

Meeting the requirements

In a statement to Nature, the EPA says the changes are meant to provide clear criteria to help determine the quality of the research used to evaluate chemicals — and that the guidance is a work in progress that can be revised in response to new information. But scientists say the process laid out by the EPA is at odds with established, peer-reviewed procedures for such assessments.

Jennifer Sass, a senior scientist at the Natural Resources Defense Council, an advocacy group based in New York City, suspects that the goals are to promote science from industry and change the calculations that the EPA uses to develop regulations and estimate safe exposure limits for chemicals.

The guidelines introduce many data reporting requirements — including statistical analyses that measure whether a study correctly identifies the presence of an effect — that are standard for industry-funded research. But because such criteria vary among peer-reviewed journals, many academic studies would be disqualified, says Tracey Woodruff, who led the development of a chemical-evaluation process at the University of California, San Francisco. “Only industry studies will survive.”

Multiple challenges

The changes represent a major shift because they create a new system for chemical-risk assessments under TSCA. Unlike IRIS, the process introduced by the Trump administration has not been peer reviewed, and yet it would allow agency officials to circumvent IRIS evaluations. Under former president Barack Obama, the EPA would have used IRIS to perform these reviews when considering regulations under TSCA.

The IRIS programme dates back to 1985, but under the Obama administration, the EPA modernized and standardized its chemical-evaluation procedures to improve transparency and confidence in its health assessments. Woodruff says that the IRIS process is solid and that bypassing it would be a mistake.

“The TSCA office is deciding to ditch all of the experts and empirical methods that have been developed over the last 30 years for a method that appears to be based on their whim and personal opinion,” she says.

But the EPA insists that the review process used in these chemical evaluations is intended to “comprehensively capture all available science”.

Friendly faces

Politicians in the US House of Representatives have also hammered IRIS, holding hearings questioning the quality and validity of the programme’s assessments. The political manoeuvring parallels efforts from industry to bypass scientific reviews of certain chemicals.

One plant in LaPlace, Louisiana, makes the chemical chloroprene for the Tokyo-based company Denka. Chloroprene is used to make neoprene, a synthetic rubber integral to products such as wetsuits. A 2010 IRIS evaluation and subsequent government studies suggested that chloroprene exposure levels in LaPlace were high enough to increase cancer risk in some areas of the city. Denka challenged that ruling last year, arguing that the assessment was incorrect. The company lost its challenge in January but has since appealed against that ruling. A panel appointed by the EPA leadership will now consider the appeal.

Denka has argued to its political allies that reducing chloroprene emissions would be too expensive, says Karl Brooks, a former EPA official who last year served as a consultant in a lawsuit filed by LaPlace residents against Denka. That’s a potentially dangerous development, he says, because IRIS assessments are meant to focus on the health effects of chemicals — not the economic challenges that a company might face as a result of the core science.

Researchers fear that the chloroprene case represents yet another strategy for companies seeking relief from the burdens of regulations: challenge the science and, when that fails, appeal to friendly politicians and political appointees.