Both Marcy Wheeler and Kirk Murphy have responded to BP’s filing with EPA (pdf) in which BP insists that they must continue the use Corexit EC9500A as the dispersant of choice in attempting to mitigate the effects of the continuing gusher a mile beneath the surface of the Gulf of Mexico. I want to expand on their findings to point out the intellectual dishonesty BP uses in supporting their decision to continue using Corexit.

Here is how BP frames the directive they received from EPA to choose a new dispersant, and their decision to ignore that directive:

BP’s response below considers the criteria set forth in the directive in the following order (1) dispersants with a toxicity value greater than or equal to 32.00 ppm LC50 toxicity value for Menidia or 18.00 ppm LC50 for Mysidopis [sic], as indicated on the NCP Product Schedule, (2) the availability based on existing stockpiles, the estimated time to begin aerial and subsurface application, and time for manufacturing, shipping and warhousing, and (3) as effective as Corexit EC9500A at dispersing the oil plume. As discussed below, given the above criteria, BP continues to believe that Corexit EC9500A is the best alternative.

Here is the NCP Product Schedule toxicity table that is referenced above:

dispersants

Note that Corexit EC9500A fails to meet criterion number one. In fact, for the Menidia toxicity analysis, it is the most toxic dispersant in the table. Five preparations meet criterion number one for toxicity.

Next, BP addresses availability, noting that they have over 200,000 gallons of Corexit EC9500A on hand and 100,000 gallons Sea Brat #4. Then, BP informs EPA that they don’t have the other agents on hand and that it will take too long to obtain supplies:

BP does not have a stockpile of the other dispersants that meet the criteria in the May 19th Directive, and the manufacturers tell us that they cannot produce the requested volume for 10 to 14 days or more.

Inexplicably, BP provides more detailed information on five dispersants alongside data from their two Corexit formulations, but only two of the five dispersants they analyzed in detail were taken from the group of five with the EPA-mandated low toxicity levels. Furthermore, they provide no more information on availability of these two agents, merely noting they will provide the information to EPA.

Despite Sea Brat #4 meeting the EPA toxicity criteria and despite having 100,000 gallons of it on hand, BP moves outside the EPA toxicity criteria to bring in an intellectually dishonest claim about Sea Brat #4 in order to eliminate it as a candidate for use. As pointed out in Marcy’s post, BP claims that one minor component of Sea Brat #4 "may degrade" to a compound that is an endocrine disruptor. As Kirk Murphy points out, the scientific literature demonstrates that dispersants as a class (and Corexit EC9500A as the usual research example) result in making the known endocrine disruptors in the oil spill itself more bioavailable to a number of organisms.

This is intellectual dishonesty taken to the extreme. BP is rejecting a much less toxic dispersant candidate because a minor component "may" break down into an endocrine disruptor, when the oil itself is providing endocrine disruptors in amounts many orders of magnitude higher than any anticipated breakdown product of a dispersant. Further, BP knows that its dispersant, and all dispersants as a class, are making the endocrine disruptors in the oil more available to the organisms they can harm. Here is a snippet from a NOAA review (pdf) of endocrine disruptors, dealing with polycyclic aromatic hydrocarbons, which are present in high amounts in crude oil and which were the subject of the scientific study Kirk found:

Polycyclic Aromatic Hydrocarbons (PAHs). The PAHs appear to depress the production or levels of circulating estrogens as well as vitellogenin in female fish. There does not appear to be much information on the effects of PAHs in male fish. PAHs have also been shown to result in lower GSIs.

[GSI = gonadosomatic index, (gonad weight/body weight X 100)]

So the bottom line is that in claiming that a minor component of Sea Brat #4 "may" break down into an endocrine disruptor, BP is focusing on the possible introduction of endocrine disruptors at probably less than a millionth (and more likely less than a billionth) of the endocrine disruptors that the dispersants are helping to become more bioavailable. There is simply no justification for BP’s exclusion of Sea Brat #4 on this basis.

It should also be noted that all five of the agents which meet EPA’s toxicity criterion also exceed Corexit EC 9500A’s performance on EPA’s measure of effectiveness on South Louisiana Crude.

Finally, BP has categorically rejected several of the more effective, less toxic dispersants by claiming that they are not available in the 10 to 14 day range. We are likely still several months away from a relief well stemming the flow from the gusher. Why does BP not offer to switch to one of the better agents at a later date when it becomes available in sufficient quantities?

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