Environmental groups filed a lawsuit Tuesday in federal court to compel the EPA to restrict use of chemical agents to clean up oil spills.

The suit, filed by the University of California-Berkley Environmental Law Clinic and the Center for Biological Diversity charges that instead of mitigating environmental harm, chemicals such as the dispersant Corexit have proven to be as or more toxic to humans than the oil alone.

The groups are suing on behalf of environmental justice and conservation groups, as well as individuals who personally experienced Corexit’s toxic effects in the Exxon Valdez and BP Deepwater Horizon oil spills.

“EPA’s delay in updating its oil-spill response plan to reflect scientific knowledge about the dangers of dispersant use is inexcusable and unlawful,” said Claudia Polsky, director of the UC-Berkeley Environmental Law Clinic.

The use of dispersants in oil-spill response is outlined in the National Contingency Plan, which governs the nation’s oil and chemical pollution emergency responses. The Clean Water Act directs the Environmental Protection Agency to periodically update the plan to account for new information and new technology.

However, EPA last update in the mid-1990s did not incorporate lessons from the long-term ecosystem studies following the Exxon Valdez disaster that occurred more than 30 years ago, the lawsuit charges.

“The EPA’s delay in revising its rules, last updated in 1994, is increasing the harm to wildlife and public health,” said Kristen Monsell, oceans program legal director at the Center for Biological Diversity.

“By continuing to rely on a plan that allows for the widespread deployment of chemical dispersants to ‘clean up’ oil spills, the EPA is placing marine ecosystems and coastal communities at risk of short- and long-term devastating impacts,” said marine toxicologist Riki Ott, director of the Earth Island Institute’s A.L.E.R.T. project, the lead plaintiff in the lawsuit.

In response to Ott and other plaintiffs, the EPA initiated a rulemaking proceeding in early 2015 and invited public comment on the use of Corexit in oil-spill response actions. By the time the rulemaking comment period closed in April 2015, the agency had received more than 81,000 responses, the majority of which called for reducing the use of chemical dispersants while decreasing their toxicity and increasing their efficacy, the suit maintains.

Since then, however, the EPA has been silent on the issue.

The EPA’s failure to to issue updated regulations, the groups assert in their lawsuit, violates the agency’s administrative obligations under the law. It also puts at risk nearly 39 percent of the U.S. population that live on the coastline, and the millions more who live near lakes, rivers, or along oil pipeline corridors.