Conservation groups are suing the Environmental Protection Agency and the Coast Guard over the use of chemical dispersants used on oil spills in marine waters.

The three groups claim the agencies are violating the Endangered Species Act because they have not studied the effects of dispersants on endangered species and critical habitat.

The lawsuit says EPA should determine the safety of dispersants on endangered species before they place them on an agency list of dispersants that can be immediately used in oil spill responses.

The lawsuit by the Center for Biological Diversity, Surfrider Foundation and Pacific Environment was filed Wednesday in San Francisco.

EPA spokesman Mark ManIntyre says the agency does not comment on pending litigation.