On May 20, in EPA's own words, the agency ordered BP --
to identify a less toxic alternative – to be used both on the surface and under the water at the source of the oil leak – within 24 hours and to begin using the less toxic dispersant within 72 hours of submitting the alternative.On the same day, however, BP replied that the large store of Corexit it had on hand:
was the only dispersant that was available immediately in sufficiently large quantities, to be useful at the time of the spill. Subsequent efforts have identified Sea Brat # 4 as a possible alternative that is equally effective at dispersing oil, but has fewer acute toxicity effects.However, BP's letter added:
Sea Brat #4 contains a small amount of a a chemical that may degrade to a nonylphenol (NP). The class of NP chemicals have been identified by various government agencies as potential endocrine disrupters, and as chemicals that may persist in the environment for for a period of years. The manufacturer has not had the opportunity to evaluate this product for those potential effects, and BP has not had the opportunity to conduct independent tests to evaluate this issue either.Several years ago, the EPA described nonylphenol in a previous advisory as --
an organic chemical produced in large quantities in the United States. It is toxic to aquatic life, causing reproductive effects in aquatic organisms. Nonylphenol is moderately soluble and resistant to natural degradation in water. It is used as a chemical intermediate and is often found in wastewater treatment plant effluent as a breakdown product from surfactants and detergents.At this afternoon's brief news conference, EPA director Jackson said the agency will continue to evaluate the dispersants identified by BP for both effectiveness and toxicity. If an alternative to Corexit 9500 in sufficient quantities can be found, she implied the agency would proceed with orders for BP to make the switch.
The root problem, however, Jackson said as she began winding up the presser, is that "the science of dispersants has not in any way kept up with the science and technology" of deep sea drilling.
Last week, Sylvia Earle, a famed oceanographer in her own right and former NOAA director, told a congressional committee, "Until we know more about the dispersants, I'd follow up with BP and EPA and tell them to stop, stop."