The EPA released peer-reviewed results from the second phase of its independent toxicity testing on the mixture of eight oil dispersants with Louisiana Sweet Crude Oil. EPA has concluded that the eight dispersants have similar toxicities to one another and to Corexit 9500 based on the mixtures' impacts on juvenile shrimp and small fish. Administrator Lisa P. Jackson asserted, "EPA has committed to following the science at every stage of this response."

University of Calgary professors have found that hormone-altering chemicals in rivers, such as synthetic estrogens and agricultural by-products, are changing the sexes of a small species of minnow. One of the researchers asserted "I think we need to look at this a little more carefully and ask, what is the message the fish are telling us. If the fish are showing bent genders and people are drinking the same water . . . we need to try to evaluate that risk.”

Although outgoing BP CEO Tony Hayward alleged that the mud BP is using to seal the well in the Gulf is not toxic, a congressional investigation has revealed that the mud is a highly toxic chemical mixture containing ethylene glycol and lye. Rep. Lois Capps (D-CA) asserts, "Time and time again, BP has failed to disclose critical data and information that is essential to our ability to track the long term effects of this spill."

The NRDC sued the FDA because the agency failed to finalize a 32 year old document that would regulate the use of triclosan and triclocarban, which are widely used and unregulated despite potential health risks, in hand soaps and body washes. The FDA revealed that these chemicals are minimally effective and data from laboratory animal studies shows that the chemicals interfere with hormones necessary for development and reproduction.