Suit filed to force release of more details on dispersants; Senate hearing set for Thursday

BP's use of chemicals to disperse the Gulf of Mexico oil spill is coming under renewed scrutiny, as environmentalists head to court to seek more information about potential health hazards and a Senate panel plans a Thursday hearing on the issue.

The company has used at least 1.8 million gallons of dispersants on the Gulf's surface and 5,000 feet deep at the source of the leak.

Earthjustice filed a federal lawsuit Wednesday in Florida to force the Environmental Protection Agency to turn over safety studies on the chemicals.

On Thursday, EPA chief Lisa Jackson is scheduled to testify on dispersants before the Senate Subcommittee on Commerce, Justice and Science.

BP says the chemicals have kept much of the spill from reaching the Gulf coast.