Turns out the main dispersant being used is Corexit. What do we know about Corexit? Not much, it turns out. Chemicals don't have to be tested for safety! Rather, the EPA has to prove that a chemical is unsafe prior to getting it pulled.
As incredible as it may seem, when [The Toxic Substances Control Act] TSCA was enacted in 1976, the law “grandfathered” the 62,000 chemicals then available for use in Commerce, without requiring that a basic set of information be disclosed about those chemicals, that they be tested, or that they meet a safety standard. Since then another 22,000 chemicals have entered the market, also without sufficient information, testing, or a requirement to meet a health-protective safety standard. From the NDRC blog.
Basically, BP has been ordered to use a safer dispersent, but refuses to because they say that they have no way of knowing whether the suggested dispersants are safer or not, or even what are in them, because the information is proprietary. This is insane. We are pumping something like 60,000 gallons of something that potentially more dangerous than the oil itself to dispurse the oil.
What I think is happening is that BP thought that they could make it appear (by way lowballing the estimates of leaking oil and by dispursing the oil (hiding it below the surface) that the leak is nowhere as bad as it is.
What I want to know is why isn't the news reporting this? I'm also appalled by the complete lack of regulation in the chemical industry. Someone has friends in high places.
For more information, I suggest reading the testimony of Gina M. Solomon, M.D., M.P.H. before Congress 6/10/10, a portion of which I quote below.
Several weeks ago, the EPA told BP that it must identify a safer and more effective
dispersant within 24 hours, and must switch to safer dispersants within three days. This was a good idea for health and the environment. BP should be required to use the safest and most effective approaches possible, rather than the most convenient or cheapest products. There are dispersants that have already been approved by EPA that appear to be both much safer and more effective than the ones BP has chosen.13
I looked into the toxicity of the Corexit 9500 and 9527 products that BP has been using, and had concerns, especially for worker safety and for the health of fish and marine mammals. The ingredients in these products - even the 2-butoxyethanol which worries me most - might not be a problem if used in small amounts. But the use of over 700,000 gallons of even modestly toxic chemicals can become a serious problem.
When BP released their response14 to the EPA order on dispersants, the flaws of the U.S. chemical safety system became clear. BP refused to switch dispersants because, among other reasons, they say there’s not enough information about their safety.
Tables in the BP memo contain a row that is supposed to list: “Persistence,
bioaccumulation, and chronic effects, and endocrine disruption” for the various
dispersants, but the boxes in that section contain the words “Proprietary mixture” for almost all the products. That means that the public has no access to the full ingredients lists of these products, or any ability to independently verify their safety. Amazingly, neither, apparently, does BP.In fact, the BP memo complains about the information gap and cites this as a reason for not switching to other dispersants. But the information gaps don’t stop there: Major portions of BP’s memo have been redacted, so the public can’t even review much of BP’s analysis of the alternatives.
According to one of the commentors at my favorite blog theoildrum.com, widespread use of dispersants can create dead zones in the ocean. I'll keep on reading.
If you're still curious, here's a nice summary article by Pro Publica.
Thanks to commenters at theoildrum.com for pointing me to most of these sites.