EPA Releases Previously Secret Ingredients of Oil Dispersants

EPA Releases Previously Secret Ingredients of Oil Dispersants

The EPA quietly published this week the formulas for Nalco's Corexit chemical oil dispersants, which have been used in unprecedented amounts to try and fight BP's gulf oil spill.

The move came unannounced -- either to the public or to Nalco, who learned about it from the news service Greenwire -- but comes after weeks of questions and concerns about the unknown but potentially serious impacts on the environment and human health from applying dispersants in such large quantities.

To date, more than 1.1 million gallons of Corexit 9527 and Corexit 9500 have been used to break up spilled oil into supposedly more easily degradable portions -- although some scientists suggest that oil broken down by dispersants remains below the surface and could harm sea life and underwater coral reefs.

Reporting for Greenwire, Elana Schor writes:

Three ingredients of the two Corexit formulas were already available on material safety data sheets that outline the human health risks of using the dispersants in the workplace. Corexit 9527, used in lesser quantities during the earlier days of the spill response, is designated a chronic and acute health hazard by EPA. The 9527 formula contains 2-butoxyethanol, pinpointed as the cause of lingering health problems experienced by cleanup workers after the 1989 Exxon Valdez oil spill, and propylene glycol, a commonly used solvent.


Corexit 9500, described by Pajor as the "sole product" Nalco has manufactured for the Gulf since late April, contains propylene glycol and light petroleum distillates, a type of chemical refined from crude oil. Nalco had previously declined to identify the third hazardous substance in the 9500 formula, but EPA's website reveals it to be dioctyl sodium sulfosuccinate, a detergent and common ingredient in laxatives.

Late last month, Nalco released a statement affirming the safety of Corexit, while not disclosing any specific details of its chemical makeup beyond what is available in the Material Safety Data Sheet for each dispersant.

Now that the chemicals have been revealed, OMBWatch takes a look at the claims Nalco made versus the reality of what's in the two Corexit formulas. Brian Tumbaugh writes:

Nalco has claimed that Corexit "is a simple blend of six well-established, safe ingredients that biodegrade, do not bioaccumulate and are commonly found in popular household products…The COREXIT products do not contain carcinogens or reproductive toxins."


The EPA website lists eight ingredients – not the six referred to by Nalco. Among the ingredients is 2-butoxy ethanol, which possesses the following characteristics:

  • 2-Butoxy Ethanol can affect you by ingestion and may be absorbed through the skin.
  • 2-Butoxy Ethanol should be handled as a CARCINOGEN--WITH EXTREME CAUTION.
  • Contact can irritate the skin and eyes with possible eye damage.
  • Inhaling 2-Butoxy Ethanol can irritate the nose and throat.
  • 2-Butoxy Ethanol can cause nausea, vomiting, diarrhea and abdominal pain.
  • Exposure can cause headache, dizziness, lightheadedness, and passing out.
  • 2-Butoxy Ethanol may damage the liver and kidneys.

Regardless of the potential health and environmental impacts of the dispersants' use, and despite reports of oil spill workers falling sick, neither BP nor the federal government have moved to replace Corexit from the spill response, with BP maintaining that the chemical is the only one available in sufficient quantities for use in fighting the massive oil spill.

But the release of the information from the EPA comes just as an advocacy coalition representing 250 environmental and health organizations called on Congress to overhaul the federal chemical regulations in the U.S., using Corexit's widespread use as an example.

"We are rolling the dice with the health of workers and marine life in the Gulf by using dispersants that we know very little about," Andy Igrejas, director of the Safer Chemicals, Healthy Families coalition, said in a statement. "We need a stronger law to ensure that chemical dispersants, and the wide variety of products that we bring into our homes and offices every day, are safe."

Oil spill photo CC-licensed by Flickr user aclintonb.