far more than 1.6 million gallons of the chemical have been injected into the Gulf of Mexico. But the struggle over daily dispersant use has caught the eye of Rep. Ed Markey, D-Massachusetts, one of the loudest critics of BP's response in cleaning up the oil spill. I think it is obvious we can never again allow for a repetition of what is happening right now, where the science experiment is being conducted without having any idea what the impact on marine life long term will be, said Markey.