Corexit

Corexit (often styled COREXIT) is a product line of oil dispersants used during oil spill response operations. It is produced by Nalco Holding Company, associated with BP and Exxon and an indirect subsidiary of Ecolab. Corexit was originally developed by the Standard Oil Company of New Jersey. Corexit is typically applied by aerial spraying or spraying from ships directly onto an oil slick. On contact with the dispersant, oil that would otherwise float on the surface of the water is emulsified into tiny droplets and sinks or (in the unusual case of sub-surface application) remains suspended in the water. In theory this allows the oil to be more rapidly degraded by bacteria (bioremediation) and prevents it from accumulating on beaches and in marshes. Corexit (often styled COREXIT) is a product line of oil dispersants used during oil spill response operations. It is produced by Nalco Holding Company, associated with BP and Exxon and an indirect subsidiary of Ecolab. Corexit was originally developed by the Standard Oil Company of New Jersey. Corexit is typically applied by aerial spraying or spraying from ships directly onto an oil slick. On contact with the dispersant, oil that would otherwise float on the surface of the water is emulsified into tiny droplets and sinks or (in the unusual case of sub-surface application) remains suspended in the water. In theory this allows the oil to be more rapidly degraded by bacteria (bioremediation) and prevents it from accumulating on beaches and in marshes. Corexit was used in unprecedented quantities during the 2010 Deepwater Horizon oil spill in the Gulf of Mexico and became the largest use of such chemicals in the United States. In addition to spraying the dispersant onto the surface slick, it was used in an untested, off-label manner when BP injected it at the broken well-head, roughly 5,000 feet below the surface. Researchers continue to examine the effects and effectiveness of Corexit. Studies have so far indicated that the dispersant is toxic to marine life. Corexit has been shown to exert a synergistic effect when mixed with oil, increasing its toxicity. Corexit was originally developed by the Standard Oil Company of New Jersey (SONJ) also known as Esso (phonetically derived from the acronym SO). The company later merged with Humble Oil to form Exxon, which is now part of ExxonMobil. In 2011, Corexit became the property of Ecolab, following a merger between Ecolab and Nalco Holding Company. As of 2015, Corexit is owned by Ecolab and is manufactured by Nalco Company, an indirect subsidiary of Ecolab. Dispersants are mixtures of surfactants and solvents that are commonly used to break up floating oil slicks into small droplets, which are submerged underwater. This reduces shoreline accumulation but increases the amount of oil underwater. This also increases the surface area of the oil and, in theory, accelerates the destruction of oil by naturally occurring bacteria. Dispersants are themselves a form of pollution that can be toxic to marine life, and the increased activity of bacteria from their presence can deplete oxygen in nearby waters, causing further harm to marine life. There are important trade-offs that must be considered in their use, such as the relative level of toxicity of the dispersant versus the relative toxicity of the spilled oil, to ensure that dispersant use mitigates an oil spill rather than to make the problem worse. Corexit products have been used in oil spill response activities since the late 1960s. Early products in the line included Corexit 7664 and Corexit 8666. Corexit 9527 is one of the first modern concentrate dispersants and has been in use since the mid 1970s. Corexit 9500 was designed to replace Corexit 9527. In 2002, Corexit 9527 and Corexit 9500 were the only two chemical dispersants stockpiled in large quantities in the U.S.A. An estimated 2.5 million gallons of chemicals were used in response to the supertanker SS Torrey Canyon oil spill in the United Kingdom in 1967. The incident harmed marine life and triggered the first significant international public discussions regarding chemical dispersants' toxicity including the costs and benefits of its deployment. In April 1968, 300 barrels of Corexit was shipped to the scene of the stricken tanker Esso Essen off the African coast. 125 barrels of it was sprayed onto the slick by aircraft over two days, after which the slick was dispersed. Corexit was later used in response to the sinking of the Greek tanker Andron off the west African coast. Following these events, Humble Oil and Refining Co. and the Enjay Chemical Company (a subsidiary of the Standard Oil Company of New Jersey) each announced the development of Corexit 7664, describing it as non-toxic to marine life- even to shrimp at concentrations of 1% per volume of seawater. Ecotoxicological studies had been undertaken by the Institute of Marine Science at the University of Miami. Corexit 7664's point of difference was described by research chemist Dr Edward Corino to be its water base, where previous dispersants had been hydrocarbon-based and highly toxic. James Avery, Humble Oil and Refining Company's public relations representative for the eastern region confirmed that following the Torrey Canyon oil spill, another spill in the Fore River from a tanker en route to Weymouth, south of Boston hastened Corexit 7664's development. In February 1969, following application tests in Montreal, Quebec, Canada, the Imperial Oil company announced that it had equipped its fleet of tankers and barges with Corexit for the purpose of dispersing oil spills.