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Toxic Dispersants

Toxic Dispersants

Dispersants, used in response to oil spills in water to remove slicks from the surface, change the chemical and physical property of oil, separating an oil slick into small droplets and increasing the mixture of the oil into the water column. Dispersant use does not reduce the total amount of oil released into the environment. Rather, it reduces oil exposure to shoreline habitat while increasing oil exposure in the water column and on the ocean’s bottom.

Dispersants & the BP Disaster

The April 2010 Macondo well blowout in the Gulf of Mexico released more than 200 million gallons of oil over the course of three months. In response, approximately 1.84 million gallons of dispersants were applied – about 1.07 million gallons of which was applied to the ocean’s surface, and, for the first time ever, 771,000 gallons of dispersant released at the site subsea. 

Corexit 9500 was the primary dispersant used. Toxicity testing shows that a mixture of Corexit 9500 and Number 2 fuel oil is more than four times as toxic as oil alone and nearly ten times more toxic than Corexit alone. It is the most toxic of all listed dispersants under required testing. The impact of the oil, dispersants and oil dispersant mixture on the natural resources of the Gulf are yet not fully known.

Testing of Dispersants Insufficient

Pursuant to the Oil Pollution Act of 1990, the Environmental Protection Agency (EPA) is required to prepare and publish a National Contingency Plan (NCP) schedule identifying “dispersants, other chemicals, and other spill mitigating devices and substances, if any, that may be used” to respond to an oil spill, as well as the waters in which such chemicals may be used and the quantities of chemicals which can be used safely in those waters. Under current EPA regulations, although a dispersant must be shown to be effective, a finding that a dispersant is toxic does not affect whether it can be listed for use. Additionally, currently manufacturers are only required to test for acute morality (death), not chronic impacts, non-lethal impacts or impacts on particularly sensitive and at-risk species.  

GRN and Our Partners Take Action

Freedom of Information Act

Very little information was available to the public about the safety of dispersants used in responding to the BP drilling disaster. This prompted the Gulf Restoration Network and the Florida Wildlife Federation, represented by Earthjustice Legal Defense Fund, to file a Freedom of Information Act request to EPA seeking the ingredient list of each dispersant eligible for use in the disaster response; the materials, including toxicity test results, submitted to EPA for listing; any health and safety studies submitted to EPA; and communications between BP and EPA concerning the selection of a dispersant.

When EPA failed to timely respond to the request, we brought suit to obtain the requested information. The EPA subsequently released most of the requested information. That information then formed the basis of The Chaos of Cleanup: An Analysis of Potential Health and Environmental Impacts of Chemicals in Dispersant Products, prepared by Earthjustice Legal Defense Fund and Toxipedia Consulting Services. 

Pushing EPA to Reform Dispersant Rules 

On October 13, 2010, Gulf Restoration Network together with the Alaska Community Action on Toxics, Cook Inletkeeper, Florida Wildlife Federation, Louisiana Environmental Action Network, Louisiana Shrimp Association, Sierra Club and Waterkeeper Alliance sent the EPA a  60-Day Notice of Intent to Sue, requesting revision of their dispersant rule to require expanded toxicity testing, establish toxicity criteria for the safe use of dispersants and require full public disclosure of product ingredients as a condition for approving them for use in response to oil spills. Although EPA agreed with the need for a revision, it was not until January 13, 2015 that EPA finally released a proposed revision to the rule. During the public comment period, thousands of GRN supporters sent in comments urging EPA to strengthen dispersant rules. We are awaing issuance of the final rule.