Corexit

Corexit is the brand name of a product manufactured by the Nalco Company series of dispersants and beach cleaning agents for combating oil spills.

Dispersants were used in 2010 by then a hitherto unprecedented extent by the oil company BP to fight the oil spill in the Gulf of Mexico in 2010 due to the sinking of the offshore oil rig Deepwater Horizon with Corexit EC9500A and Corexit EC9527A. It claims to be the EPA about seven million liters of dispersants have been sprayed. Controversial was used in particular because of the high compared to other dispersants ecotoxicity of resources.

Brand History

The first Corexit products were developed by a subsidiary of the oil company Exxon in the late 1960s. Since it is used regularly, 1979 Corexit 9527 after the disaster at the oil rig Sedco 135F, then the largest oil spill in history or the oil spill of the Exxon Valdez in Alaska in 1989. In 1994, the Exxon Chemical Company of range in a joint subsidiary with the water treatment specialized chemical company Nalco, which Nalco / Exxon Energy Chemicals, which after the acquisition of Exxon shares rose in full Nalco 2001.

In the UK, the European country that most sets of spills on the use of dispersants, the rocky coasts are because of the excessive toxic effect in a test, simulated, admitted no Corexit dispersants more since 1998.

After the disaster of the Deepwater Horizon BP bought up all the stocks of Corexit. Nalco's share price rose by in May 2010 by ten percent. Through the sale of the agent to BP, Nalco, which is staffed intertwined with the oil industry has already made $ 40 million in sales since the explosion. On 19 May 2010 the Environmental Protection Agency of the United States called on BP, within 24 hours, select less toxic alternatives to Corexit from the list of EPA - approved products and use.

Corexit EC9527A and EC9500A

The classified as hazardous constituents of these products are well known in the safety data sheets of the manufacturer. Since June 2010, all components are known for publication by the Environmental Protection Agency in detail, but information about the exact composition are still not public. The manufacturer had previously indicated that it is a total of six components. The safety risk performs the following substances as constituents of Corexit EC9527A earlier than 9527 Corexit referred to: the solvent 2-butoxyethanol, salts of organic sulfonic acids in which it is surfactants, as well as a small proportion of propylene glycol. Designated for Corexit EC9500A earlier than Corexit 9500, are listed as hazardous substances: hydrogenated light petroleum distillates ( petroleum -like solvents), salts of organic sulfonic acids ( surfactants) and a lower proportion of propylene glycol. According to information of the manufacturer Nalco to the U.S. Environmental Protection Agency are in Corexit, the following substances contain: Docusate sodium, sorbitan monooleate, polysorbate 80, polysorbate 85, propane -1 ,2 -diol and butyl glycol.

According to the registration data to the Environmental Protection Agency and Corexit EC9500A EC9527A are more toxic and less effective as dispersants other manufacturers. Corexit EC9500A achieved with variety of South Louisiana Crude Oil an efficiency of dispersion of 54.7 percent, a 63.4 percent Corexit EC9527A, reach about 90 to 100 percent during a number of other products. The lethal concentrations LC50 for New World silversides of the genus Menidia and suspended shrimps of the genus Mysidopsis are between 2.6 ppm and 6.6 ppm compared to 25 ppm to 57 ppm in the ecotoxic best of the more effective products and 58.4 ppm to 100 ppm in the ecotoxic best the comparable effective products.

In experimental studies on cell cultures could be shown that lung epithelial cells suffer through the influence of the above dispersants by necrotic, apoptotic and autophagic cell death effects.