© Daniel Beltra courtesy GreenpeaceA plane sprays dispersant over the oil leaked from the BP wellhead in the Gulf of Mexico, May 21, 2010.

Washington, DC - Five of the 57 ingredients in dispersants approved by the U.S. Environmental Protection Agency for use on oil spills are linked to cancer, finds a new research report based on data obtained through a Freedom of Information Act request by environmental groups on the Gulf of Mexico.

The report from Earthjustice, an environmental law firm, along with Toxipedia Consulting Services, is based on material released by the U.S. EPA in response to a Freedom of Information Act request made by Earthjustice on behalf of the Gulf Restoration Network and the Florida Wildlife Federation.

Dispersants are used to clean up oil spills and contain chemicals that break up oil into smaller droplets and move the oil from the surface of the water into the water column.

Two oil dispersant products were used heavily in the BP oil leak: COREXIT 9500 and 9527, both produced by Nalco/Exxon. BP used over 1.8 million gallons of dispersant during the three-month long oil leak that gushed 4.9 million barrels of crude oil from the Macondo well located about 40 miles southeast of the Louisiana coast.

The report "The Chaos of Clean-Up: Analysis of Potential Health and Environmental Impacts of Chemicals in Dispersant Products" highlights the fact that some dispersants are safer than others.

"The testing can't be done in the moment of the disaster," said Marianne Engelman Lado, an attorney with Earthjustice. "It has to be done ahead of time to avoid the chaos we witnessed during the disaster response to the Deepwater Horizon disaster."

Among the dispersant chemical ingredients linked to cancer are:
  • Amides, coco, N,N-bis(hydroxyethyl), which is classed as a likely carcinogen
  • Cyclohexene, 1 - methyl - 4 - (1 - methylethenyl) -, (4R) -, which is classed as carcinogenic to rats
  • Ethanol, 2-butoxy- which is listed as a possible carcinogen
  • Petroleum distillates, hydrotreated light, which are classed as a confirmed animal carcinogens with unknown relevance to humans. These distillates carry the additional warning that exposure by inhalation can cause dizziness, headache, nausea, drowsiness, and unconsciousness and prolonged inhalation of high concentrations may damage the respiratory system.
Gulf residents continue to suffer health effects related to the disaster clean-up. "The illnesses we observed were quite unique and different from anything that I had ever witnessed before," said Dr. Michael Robichaux, a physician in Raceland, Louisiana.

"Although there were scores of complaints early on, the main problems at this time are a loss of memory, seizure type problems, severe abdominal pain, fatigue, irritability and other neurological and endocrine manifestations," he said.

Click here for a chart that breaks down the ingredients in dispersants and their effects on humans, wildlife and the aquatic environment.

Earthjustice went to court to obtain the ingredients of dispersants eligible for use, health and safety studies on the chemicals in dispersants, and the application materials and toxicity testing results submitted to EPA by dispersant manufacturers seeking to obtain eligibility status for their dispersant.

The request also sought correspondence between the EPA and BP about the selection of an appropriate dispersant during the Deepwater Horizon disaster.

"The goal here is, when dispersant use is required, we use the least toxic dispersants that are appropriate to that specific spill condition," said Manley Fuller of the Florida Wilderness Federation. "To do that, we need to know the ingredients and they need to be tested in field conditions." has made information on the chemicals accessible to the public for the first time through its website.

Cyn Sarthou, executive director of the Gulf Restoration Network, is concerned that choices among dispersants are not being made publicly with full knowledge of their impacts.

"Despite ongoing concerns from the public about the toxicity of listed dispersants and their impacts upon the environment," she said, "the EPA continues to protect the dispersant manufacturers, who want to keep the ingredients of their products secret."