EDF Health

Not so fast: Why dispersants EPA ranks as “practically non-toxic” are still a concern

By Richard Denison / Published: July 2, 2010

Richard Denison, Ph.D., is a Senior Scientist.

To judge by the headlines and leads of stories that ran on the websites of the New York Times (“The E.P.A. on Dispersants: Cure Is Not Worse Than the Disease”) and the Washington Post (“Oil dispersant does not pose environmental threat, early EPA findings suggest”) reporting on an EPA conference call held Wednesday, you’d think the first round of test results on dispersants conducted by EPA answered all outstanding questions and gave their use a clean bill of health.

Hardly.  (Despite the misleading headlines and leads, the rest of these stories were more nuanced and more accurate.)

As I reported in a post Wednesday, the new acute toxicity data were from tests conducted on the dispersants by themselves, rather than mixed with oil – which is what the environment sees.  Moreover, the new data did little more than confirm already available data showing that currently listed dispersants exhibit relatively low acute toxicity to fish and shrimp, and that by themselves they are less toxic than oil by itself.

So despite the hoopla, the new data from this first round of testing are of very limited utility in answering any of the more profound questions surrounding the use of dispersants.  Read More »

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Hurry up and wait: Not much new revealed by EPA’s initial round of dispersant toxicity testing

By Richard Denison / Published: June 30, 2010

Richard Denison, Ph.D., is a Senior Scientist.

EPA held a press call today to discuss the initial results of its own testing of oil spill dispersants.  The testing by EPA was initiated after BP resisted complying with an EPA-Coast Guard Directive issued May 20 that directed the company to identify and switch to dispersants that are less toxic and more effective than the two Corexit® dispersants on which BP has exclusively relied to mitigate the effects of the oil disaster unfolding at Deepwater Horizon.  In expressing disappointment with BP’s response to the Directive, EPA indicated it would initiate its own toxicity and effectiveness testing of Corexit and other dispersants.  Today’s call reported on round 1 of that testing.

First let me say I applaud EPA for taking on the unglamorous task of conducting further testing and seeking to answer questions that would have been nice to have had answers to well before this mess developed.  Second, I understand that testing takes time, that this is only round one and EPA says more is coming, so that at least partially compensates for the distinctly anticlimactic feeling I had listening in on today’s call.

So, what did we learn today?  Not too much new. Read More »

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Does dispersant toxicity count? No toxicity standard limits EPA’s listing of oil spill dispersants

By Richard Denison / Published: June 24, 2010

Richard Denison, Ph.D., is a Senior Scientist.  EDF’s Health Program Intern Shannon O’Shea provided valuable assistance in the research for this post.

The more I have looked into the question of how dispersants get listed and selected under the country’s National Oil and Hazardous Substances Pollution Contingency Plan (NCP), the more disturbing it gets.

It turns out EPA regulations impose no maximum toxicity limits on dispersants allowed to be listed on the NCP Product Schedule.  Nor is such a listing deemed by EPA to be an approval or authorization for use of a dispersant on a spill – it merely signifies (with one exception) that required data have been submitted to EPA.  Yet, once listed, a dispersant is effectively “pre-authorized” for use, and the guidance provided to officials charged with deciding whether to allow use of a dispersant, and if so which one and in what quantities and settings, makes scant mention of toxicity as a factor to be considered in the selection decision.

No wonder there’s little incentive to do the research needed to understand the full scope of impacts associated with dispersant use, let alone to develop and shift to safer and more effective dispersants.

This post examines the following questions:

  • How does a dispersant get listed on the NCP Product Schedule?
  • Is listing of a dispersant considered approval for use on a spill?
  • How is a dispersant approved for use in a spill?
  • How are decisions made about dispersant use?
  • How is toxicity information considered in making decisions about dispersant use?

Read More »

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Is BP complying with the Directive to reduce dispersant use in the Gulf?

By Richard Denison / Published: June 21, 2010

Richard Denison, Ph.D., is a Senior Scientist.

[Note added 6/22:  I have corrected one of the figures below, which was based on a misunderstanding of the EPA/Coast Guard Directive.  Please see this correction for the updated information and a statement from EPA.]

As of yesterday, BP’s use of dispersants to address the ongoing Deepwater Horizon spill has topped 1.4 million gallons.

On May 26, 2010, EPA and the Coast Guard issued a Directive to BP calling for significant reductions in BP’s use of dispersants.  That directive set out three requirements:

  • Eliminate surface application of dispersant except in rare cases where exemptions are requested in writing and granted by the Coast Guard’s Federal On-Scene Coordinator (FOSC).
  • Limit subsurface application of dispersant to a maximum of 15,000 gallons per day.
  • Overall goal of reducing dispersant use by 75%.

Has BP complied?  The short answer is not even close.  The details follow.  Read More »

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EPA data show dispersants plus oil are more toxic than either alone

By Richard Denison / Published: June 14, 2010

Richard Denison, Ph.D., is a Senior Scientist.

In an earlier post, I noted in haste some apparent discrepancies between EPA and BP acute toxicity data on the Corexit® dispersants.  Little did I realize that the data mixup was actually telling me something much more significant:  that the dispersant maker’s own test data demonstrate that the combination of oil plus dispersant is quite a bit more toxic than the dispersant alone and – even more significant – the combination is more acutely toxic than the oil by itself.

Let me repeat that:  The data indicate that dispersed oil is more toxic than undispersed oil.  Read More »

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Another BP leak – this time, it’s their 2009 Gulf of Mexico oil spill contingency plan

By Richard Denison / Published: June 6, 2010

Richard Denison, Ph.D., is a Senior Scientist.

Just as BP seems to be making some progress in slowing the leakage of oil from Deepwater Horizon, another leak has appeared.  Karen Dalton Beninato, writing on NewOrleans.com, has obtained, and posted for all to see, a copy of BP’s June 2009 “Gulf of Mexico Regional Oil Spill Response Plan” (caution, it’s a 600-page, 29 MB PDF file!).  [Note added 6/8:  Not sure how long it’s been posted, but the BP Plan is up on the Minerals Management Service website, under “Documents” here (double caution:  this version is a 61 MB PDF!)]

There are some embarrassing parts, with no doubt more waiting to be discovered.  Here’s one example:  The Plan’s “worst-case scenario” for sites more than 10 miles offshore is a total leakage of 177,400 barrels of crude oil (Appendix H).  As reported by the Washington Post this morning, government estimates put the size of this spill at between 23 and 47 million gallons, or between 548,000 and 1.12 million barrels, and counting.

On the issue of dispersants, the Plan is also revealing.  Read More »

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