A coalition of environmental groups have waged a lawsuit against the Environmental Protection Agency for its latest round of chemical regulations.

Last year, the EPA was given the task of stepping up risk evaluations for toxic substances under new chemical laws. Now that the agency is spelling out its exact plans for implementing those laws, several environmental groups say it has substantially weakened plans that were laid out under the Obama administration.

One of the rules in question has to do with how the EPA will decide which applications of a chemical will fall under its risk evaluations. According to a report in Scientific American, the Obama administration defined these “conditions of use” broadly so that the agency could cast a wider net with its analysis. Under the current EPA, however, the definition has become more stringent. Now, the agency does not have to consider “legacy uses” for chemicals, for example. This includes previous applications for chemicals that have since been banned. Several flame retardants fall into this category.

But critics charge that past exposure to certain chemicals can still have ramifications today.

“When you’re assessing a chemical, it’s important to look at all the uses to understand the actual risk in the real world,” Richard Denison, a lead senior scientist at the Environmental Defense Fund, said.

A senior director from the American Chemistry Council countered that the EPA isn’t skirting evaluations — it just decided that it did not need to “prioritize its resources” on legacy uses.

The groups also say that chemical companies will have too much input about which chemicals are given high priority for evaluations, and that there are too many “loopholes” for manufacturers.

“After Congress took bipartisan action to make desperately needed updates to our chemical safety laws, the Trump administration has turned back the clock, leaving families and workers at risk,” said Eve Gartner, an attorney for Earthjustice, one of the organizations involved the suit.