BP PLC says it is going to stick with the main chemical dispersant it’s been using to fight the Gulf of Mexico oil spill, despite directions from the Environmental Protection Agency to use a less toxic agent.

BP Chief Operating Officer Doug Suttles says the chemical dispersant, called Corexit 9500, remains “the best option for subsea application.”

He says that tests show Corexit was among the most effective agents at dispersing the oil. And he said Corexit was the only dispersant available immediately and at great enough quantities to be used on the spill.

Louisiana Governor Bobby Jindal, members of Congress and environmental groups have raised questions about the dispersants, which are being shot into the oil plume thousands of feet beneath the sea.

The EPA didn’t immediately respond to e-mails seeking further comment yesterday.