Corexit: the Musical!

May 28, 2010 by

A Nalco press release today on Rigzone restates the company’s claim that Corexit is the safest possible dispersant available for use in oil related disasters. Nalco claims that the “safer” Corexit 9500 is the only disperant they are manufacturing for use in the Gulf. Perhaps true but possibly misleading as BP lists 80,345 gallons of the more toxic Corexit 9527 among its weapons for fighting oil slicks and it has already been reported that both versions have been applied in the current disaster. (That’s one-tenth of the 830,000 gallons of Corexit which has been used to date in the Gulf.)

Nalco also claims that the EPA’s Lisa Jackson and RAdm Mary Landry have both touted the positive effects Corexit has had on the oil in the Gulf but this must be taken with a grain of salt. While I’ll refrain from commenting on Landry’s fine ombudsmanship of BP, on May 24th, Jackson is quoted as saying, “Our tracking indicates that the dispersants are breaking up the oil and speeding its biodegradation, with limited environmental impact at this time.” For the records, dispersants do nothing to biodegrade oil. Biodegradation is a natural process which happens with or without application of dispersants. The only thing dispersants do is help the oil lose cohesive bond with itself and the surface, allowing it to sink out of sight.

Unfortunaltely it also increases the area of the oil. From a May 11th Fast Company article:

“They’re also called dispersants for a reason. The chemicals break up the oil and then disperse it, so instead of having the oil collect at the surface, dispersed droplets of oil can spread more quickly and in more directions. This means the droplets linger longer in the water, collecting on the seabed and harming the ecosystem offshore.”

The article also mentions toxicology expert Dr William Sawyer’s claim that Corexit is also known as deodorized kerosene.

The press release then mentions six ingredients of Corexit –not by name, of course– and how they can be found in everyday products such as soap, shampoo, hand creams and household cleaners. Well, they must be safe, right? No one ever got sick from eating soap, right? Just because these chemicals are safe in one setting does not mean they are safe together! Bleach and ammonia by themselves are bad enough but mix them together and you can actually kill yourself from the resultant fumes!

In the “Safety” section of the press release there is this statement:

“Data published by Environment Canada, that country’s main environmental agency, in 1991 showed common household dish soap as having a substantially higher rainbow trout toxicity than COREXIT 9527. Put another way, COREXIT 9527 is more than 7 times safer than dish soap. COREXIT 9500 is the next generation of COREXIT products and features an improved formula.”

What? When you strip the blah-blah from that, it reads: Corexit 9527 is safer than dish soap for rainbow trout. Corexit 9500 is different from 9527 so it’s better. The two statements have NOTHING to do with one another but the spin certainly paints a pretty safe picture! As for the tests on trout, last time I looked there was a slight difference beetween trout and human biology.

The “Biodegredation” section reads thus:

“A March, 1994, report created by France’s Institut National de L’Enviroenment Industriel et des Risques indicated that COREXIT 9500 largely biodegraded in 28 days. COREXIT oil dispersant was first applied to the Gulf oil slick on April 23.”

Well, that’s cool. Gone in 28 days! Except for that “largely” stuck in the middle there. The fact is that the independent lab test –required by France but not the US– stated that 78% of the product degraded over 28 days as reported by the Bellingham Herald. I don’t know how long the other 22% lingered but this means that after a month there may be as much as 182,600 gallons (of the 830,000 gallons used so far) of Corexit floating around in the Gulf. What is the half-life of the remaining 22%?

The Nalco data suggests that Corexits degradation happens from the time it hits the surface of the water to a depth of 10 meters (32 feet). Processes differ at different temperatures and pressures. Can Nalco’s data be trusted to remain accurate at a depth of 5000 feet?

The press release closes with a section on “Application” which again states that Corexit should be sprayed from planes and boats. Nowhere does it recommend dumping gallons of Corexit a mile below the surface.

-M Styborski

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