The U.S. Environmental Protection Agency must consider tightening its corrosive dust limits, after a lawsuit filed on behalf of the World Trade Center first responders who sustained lung damage after toiling in heavily polluted air in the aftermath of the 9/11 terrorist attacks.

The California agency that’s supposed to help protect workers from on the job hazards and investigate working condition safety issues is doing a lackluster job, the U.S. Department of Labor says.