http://globalwarming.house.gov/mediacenter/letters?id=0044#main_contentsnip: To date, BP has used approximately 705,000 gallons of a trademarked dispersant called Corexit on the ocean surface and approximately 115,000 gallons of the dispersant subsurface, at the source of the spill. According to EPA , the Corexit products selected are among the most toxic and least effective dispersants approved for use. Some Corexit formulations were banned in the United Kingdom more than a decade ago because of their toxicity to some aquatic life.
I am concerned that because these toxic chemicals were not intended to be used for such long durations, and were not intended to be used at such depths, there could be serious and unknown long-term consequences for the marine ecosystem, the food chain and human health. snip
EPA recognizes the environmental tradeoffs that results from the use of these chemicals, which is why they have directed BP to identify and utilize a less toxic and more effective product and dedicated its own scientists to assist in these efforts.
Despite this directive, BP continues to insist on the use of its choice Corexit dispersant. The truth is we know little about the long-term ecological effects of the use of any dispersants, and how these dispersants may, as result of contaminating the aquatic food chain, also impact human health. snip