One of the most alarming stories to emerge from the entire BP Gulf oil crisis has been the company's penchant for using toxic chemical dispersants to try to break up and spread out the oil — and that the federal government had approved the tactic. As a result, thus far some 600,000 gallons of toxic, experimental chemicals have been dumped on the spill, both at the source of the leak and on the surface slick. But it looks like the EPA has finally come to its senses — it has given BP 24 hours to stop using the toxic Corexit chemical, and to find a better tested, safer one instead. The official announcement has not yet been made, but is expected to come in later this afternoon. Here's the Washington Post on why the decision was reached amongst federal regulators: The move is significant, because it suggests federal officials are now concerned that the unprecedented use of chemical dispersants could pose a significant threat to the Gulf of Mexico's marine life. BP has been using two forms of dispersants, Corexit 9500A and Corexit 9527A, and so far has applied 600,000 gallons on the surface and 55,000 underwater. Indeed — I can tell you firsthand that conservation scientists, marine biologists, and environmentalists on the group on the Gulf put the use of the chemical dispersants at the top of their list for concern. The move to cut off its use may have been a result of the continued activism from Rep. Edward Markey, who has called the dispersants into question, as well as demand that BP give the public more information (and access to video) of the leak itself. Here's a statement from a letter the representative sent to EPA administrator Lisa Jackson: The release of hundreds of thousands of gallons of chemicals into the Gulf of Mexico could be an unprecedented, large and aggressive experiment on our oceans, and requires careful oversight by the Environmental Protection Agency (EPA) and other appropriate federal agencies. He notes that the chemical was banned in Britain an entire decade (!) ago for being too toxic as well as only dubiously effective. Here's an excerpt from his response to the Obama administration's decision to cut out Corexit: “The tests used to measure the toxicity of dispersants involve only a 96-hour dose to the marine animals that will be exposed to them – clearly, their effects when they're used over longer periods might be significantly more damaging. The release of hundreds of thousands of gallons of chemicals into the Gulf of Mexico could be an unprecedented, large and aggressive experiment on our oceans. We must ensure that these chemicals, which are being touted as a way to mitigate the effects of the spill, first do no harm to marine life.” I thought it absolutely outrageous that a 96 hour test cycle was deemed adequate to commence dumping tens of thousands of experimental toxic chemicals into the Gulf. Kudos to Rep. Markey for hearing the very valid concerns of scientists and acting. More on the Gulf Oil Spill Chemical Dispersants 101: How They Work (Video) http://www.treehugger.com/files/2010/05/chemical-dispersants-101-how-work-video…. From Dispersants to Mushrooms and Hair: How to Clean Up an Oil Spill http://planetgreen.discovery.com/travel-outdoors/howto-clean-oil-spill.html added by: captainplanet71