Misplaced Pages

Corexit: Difference between revisions

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Browse history interactively← Previous editContent deleted Content addedVisualWikitext
Revision as of 18:45, 20 June 2010 editRenamed user e8LqRIqjJf2zlGDYPSu1aXoc (talk | contribs)37,368 editsm Use: delink the specific product names, which just redirect here← Previous edit Latest revision as of 00:46, 15 August 2024 edit undoGreenC bot (talk | contribs)Bots2,565,112 edits Move 1 url. Wayback Medic 2.5 per WP:URLREQ#articles.latimes.com 
(649 intermediate revisions by more than 100 users not shown)
Line 1: Line 1:
{{Short description|Oil dispersant}}
{{Copyedit|date=June 2010}}
] in the Gulf of Mexico.]] ] in the Gulf of Mexico.]]

'''Corexit''' is a product line of ]s primarily used as a ] for breaking up ]s. It is produced by ] which is associated with ] and ].<ref>{{cite web|author=By PAUL QUINLAN of Greenwire |url=http://www.nytimes.com/2010/05/13/business/energy-environment/13greenwire-less-toxic-dispersants-lose-out-in-bp-oil-spil-81183.html |title=Less Toxic Dispersants Lose Out in BP Oil Spill Cleanup |publisher=NYTimes.com |date=2010-05-13 |accessdate=2010-06-10}}</ref> Corexit is the most-used dispersant in the ] in the Gulf of Mexico, with COREXIT 9527 having been replaced by COREXIT 9500 after the former was deemed too toxic.<ref name="BielloSA">{{Cite web
'''Corexit'''<ref>{{Cite web |url=http://lmrk.org/corexit_9500_uscueg.539287.pdf |title=Archived copy |access-date=2010-06-26 |archive-url=https://web.archive.org/web/20100604052808/http://lmrk.org/corexit_9500_uscueg.539287.pdf |archive-date=2010-06-04 |url-status=dead }}</ref> (often styled COREXIT)<ref>{{Cite web|url=https://www.ecolab.com/nalco-water|archive-url=https://web.archive.org/web/20130411144640/http://www.nalco.com/applications/corexit-technology.htm|url-status=dead|title=Reinventing the Way Water is Managed|archive-date=April 11, 2013|website=The Global Leader in Water, Hygiene and Energy &#124; Ecolab}}</ref> is a product line of ] used during ] response operations. It is produced by ], an indirect subsidiary of ].<ref>{{cite news|author=PAUL QUINLAN of Greenwire |url=https://www.nytimes.com/2010/05/13/business/energy-environment/13greenwire-less-toxic-dispersants-lose-out-in-bp-oil-spil-81183.html |title=Less Toxic Dispersants Lose Out in BP Oil Spill Cleanup |work=] |date=2010-05-13 |access-date=2010-06-10}}</ref> Corexit was originally developed by the ] of New Jersey.<ref name=":02">{{Cite news|url = https://www.newspapers.com/clip/1571872/corexit_7664_early_account_1968/|title = Esso develops oil dispersant|date = 1968-10-09|access-date = 2015-01-15|newspaper = The Corpus Christi Caller-Times}}</ref> 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 ] 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 (]) and prevents it from accumulating on beaches and in marshes.<ref>Davies, L.; Daniel, F.; Swannell, R.; Braddock, J. Biodegradability of Chemically-dispersed Oil. Report produced for the Minerals Management Service (MMS), Alaska Department of Environmental Conservation (ADEC) and the United States Coast Guard (USCG). March 2001. http://dec.alaska.gov/spar/perp/r_d/aeat.pdf {{Webarchive|url=https://web.archive.org/web/20140630131522/http://dec.alaska.gov/spar/perp/r_d/aeat.pdf |date=2014-06-30 }} (accessed May 7, 2012)</ref><ref name="EPAonDispersants2" /><ref name="Rosenwaks" />
|url= http://www.scientificamerican.com/article.cfm?id=is-using-dispersants-fighting-pollution-with-pollution |author=David Biello

|title=Is Using Dispersants on the BP Gulf Oil Spill Fighting Pollution with Pollution?|Publisher= Scientific American
Corexit was used in unprecedented quantities during the 2010 ] in the Gulf of Mexico<ref name="BielloSA" /> and became the largest use of such chemicals in the United States.<ref name="SciAmCorexit">{{cite web|title=Is Using Dispersants on the BP Gulf Oil Spill Fighting Pollution with Pollution?|url=http://www.scientificamerican.com/article/is-using-dispersants-fighting-pollution-with-pollution/|work=Scientific American|access-date=22 April 2014}}</ref> 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 {{cvt|5000|ft|m|order=flip}} below the surface.<ref>{{cite news| url=https://www.latimes.com/archives/la-xpm-2010-sep-04-la-sci-dispersants-20100905-story.html | work=Los Angeles Times | first=Amina | last=Khan | title=Oil dispersant effects remain a mystery | date=September 4, 2010}}</ref> Researchers continue to examine the effects and effectiveness of Corexit. Studies have so far indicated that the dispersant is ].<ref name="VICEvideo">{{unreliable source?|date=August 2014}}{{cite web|title=VIDEO: Is the BP Oil Spill Cleanup Still Making People Sick?|url=https://www.motherjones.com/blue-marble/2014/05/bp-oil-spill-cleanup-still-making-people-sick|work=VICE/HBO|publisher=Mother Jones|access-date=17 May 2014}}</ref> Corexit has been shown to exert a synergistic effect when mixed with oil, increasing its toxicity.<ref name="autogenerated3">{{Cite web |title=Gulf of Mexico Clean-Up Makes 2010 Spill 52-Times More Toxic |url=https://biosciences.gatech.edu/news/gulf-mexico-clean-makes-2010-spill-52-times-more-toxic-1 |website=www.news.gatech.edu}}</ref>
|work=scientificamerican.com |date=18 June, 2010

|accessdate=19 June 2010
== Ownership ==
}}</ref>
Corexit was originally developed by the Standard Oil Company of New Jersey (SONJ) also known as Esso (phonetically derived from the acronym SO).<ref name=":02"/> The company later merged with ] to form Exxon, which is now part of ].

In 2011, Corexit became the property of Ecolab, following a merger between Ecolab and ]. As of 2015, Corexit is owned by ] and is manufactured by Nalco Company, an indirect subsidiary of Ecolab.

==Use== ==Use==

One of the most notable uses of Corext was during the 1989 ] disaster in Alaska. In 2010, '''Corexit EC9500A''' and '''Corexit EC9527A''' <ref>{{cite web|url=http://www.dailycomet.com/article/20100608/LETTERS/100609403/-1/opinion0201?Title=Oil-dispersants-safe-or-toxic- |title=Oil dispersants: safe or toxic? |publisher=DailyComet.com |date=2010-06-08 |accessdate=2010-06-10}}</ref> were used in unprecedentedly large quantities in the ].<ref></ref> On May 19, 2010 the ] gave ] 24 hours to choose less toxic alternatives to Corexit, selected from the list of EPA-approved dispersants on the National Contingency Plan Product Schedule,<ref name="Environmental Protection Agency">{{cite article |url=http://www.epa.gov/emergencies/content/ncp/product_schedule.htm |title=National Contingency Plan Product Schedule |publisher=Environmental Protection Agency |date=2010-05-13 |accessdate=2010-05-21}}</ref> and begin applying them within 72 hours of EPA approval of their choices but BP refused to change from Corexit, citing safety and availability concerns with alternatives.<ref>{{cite article |title=Dispersant Monitoring and Assessment Directive – Addendum |date=2010-05-20 |publisher=Environmental Protection Agency|accessdate=210-05-20}}</ref> BP has used Corexit EC9500A and Corexit EC9527A thus far, applying {{convert|800,000|USgal|l}} total,<ref>{{cite news |url=http://www.nytimes.com/gwire/2010/05/24/24greenwire-secret-formulas-data-shortages-fuel-arguments-o-9112.html |title=Secret Formulas, Data Shortages Fuel Arguments Over Dispersants Used for Gulf Spill |publisher=New York Times |author=Paul Quinlan |date=2010-05-24 |accessdate=2010-05-24}}</ref> but more accurate estimates run as high as {{convert|1,000,000|USgal|l}} underwater.<ref>{{cite news |url=http://views.washingtonpost.com/climate-change/post-carbon/2010/05/epa_demands_less_toxic_dispersant.html |title=Post Carbon: EPA demands less-toxic dispersant |author=Juliet Eilperin |publisher=Washington Post |date=2010-05-20 |accessdate=2010-05-20}}</ref>
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.<ref name="EPAonDispersants2">{{Cite web|url=http://www.epa.gov/bpspill/dispersants-qanda.html#q012|title=EPA Response to BP Spill in the Gulf of Mexico -- Questions and Answers
|url-status=dead | archive-url=https://web.archive.org/web/20100812023009/https://www.epa.gov/bpspill/dispersants-qanda.html | archive-date=August 12, 2010 }}</ref> 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.<ref name="EPAonDispersants2" /><ref name="SA Biello 20102" /> 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 making the problem worse.<ref name="SA Biello 20102"> Scientific American. Biello, 2010</ref>

Corexit products have been used in oil spill response activities since the late 1960s.<ref>{{Cite news|url = https://www.newspapers.com/clip/1571672/account_of_german_tanker_oil_spill_and/|title = Mopping up the seas|date = 1968-09-23|access-date = 2015-01-15|newspaper = The Anniston Star|location = Anniston, Alabama}}</ref> Early products in the line included Corexit 7664<ref name=":02"/> 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.<ref>{{Cite book|title = Assessment of the use of dispersants on oil spills in Californian marine waters|publisher = S.L. Ross Environmental Research Ltd.|year = 2002|pages = 30|url = http://www.bsee.gov/Technology-and-Research/Oil-Spill-Response-Research/Reports/400-499/413AA/|access-date = 2015-01-21|archive-url = https://web.archive.org/web/20150121113946/http://www.bsee.gov/Technology-and-Research/Oil-Spill-Response-Research/Reports/400-499/413AA/|archive-date = 2015-01-21|url-status = dead}}</ref>

An estimated 2.5 million gallons of chemicals were used in response to the supertanker ]'' '']'' ''in the United Kingdom in 1967''.''<ref>{{Cite news|url = https://www.newspapers.com/clip/1943557/oil_pollution_fears_hit_worlds_nations/|title = Oil pollution fears hit world's nations|date = 1968-08-31|access-date = 2015-03-08|newspaper = Anderson Herald}}</ref>'' ''The incident harmed marine life and triggered the first significant international public discussions about chemical dispersants' toxicity including the costs and benefits of its deployment.<ref>{{Cite news|url = http://nla.gov.au/nla.news-article134400217|title = Oil and the Great Barrier Reef|last = Burns|first = Andrew|date = 1979-07-23|access-date = 2015-01-21|newspaper = Woroni}}</ref><ref>{{Cite news|url = https://www.newspapers.com/clip/1572265/new_forumlation_chemical_disperses_oil/|title = New formulation. Chemical disperses oil spill; Fish safe|last = Beckman|first = Robert|date = 1968-05-12|access-date = 2015-01-21|newspaper = Independent Press-Telegram|location = Long Beach, California}}</ref>

=== 1968–1988 ===
In April 1968, 300 barrels of Corexit were shipped to the scene of the stricken tanker ''Esso Essen'' off the African coast.<ref name=":12">{{Cite news|url = https://www.newspapers.com/clip/1571659/editorial_noting_early_examples_of/|title = Editor's scratch pad|last = Moore|first = Dick|date = 1968-12-27|access-date = 2015-03-08|newspaper = The Daily Times|location = Salisbury, Maryland}}</ref> 125 barrels of it was sprayed onto the slick by aircraft over two days, after which the slick was dispersed.<ref>{{Cite news|url = https://www.newspapers.com/clip/1943455/early_account_of_corexit_oil_spill/|title = Guppy says yanks moved North Pole|last = Amundson|first = Rod|date = 1968-12-26|access-date = 2015-03-08|newspaper = The High Point Enterprise|location = High Point, North Carolina}}</ref> Corexit was later used in response to the sinking of the Greek tanker ''Andron'' off the west African coast.<ref name=":12" /> Following these events, ]. 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 ].<ref>{{Cite news|url = https://www.newspapers.com/clip/1943302/chemicals_break_up_oil_slick_not_toxic/|title = Chemicals break up oil slick|last = Hines|first = William|date = 1969-01-02|access-date = 2015-03-08|newspaper = The Times Recorder|location = Zanesville, Ohio}}</ref> 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 ] from a tanker en route to ], south of ] hastened Corexit 7664's development.<ref>{{Cite news|url = https://www.newspapers.com/clip/1589908/chemical_firm_mixes_oil_and_water/|title = Chemical firm mixes oil and water successfully|date = 1968-12-11|access-date = 2015-03-08|newspaper = Naugatuck Daily News|location = Naugatuck, Connecticut}}</ref>

In February 1969, following application tests in ], Canada, the ] company announced that it had equipped its fleet of tankers and barges with Corexit for the purpose of dispersing oil spills.<ref>{{Cite news|url = https://www.newspapers.com/clip/1572007/new_oil_dispersant_tested_in_monteal/|title = New oil dispersant|date = 1969-02-08|access-date = 2015-03-08|newspaper = The Ottawa Journal}}</ref>

In February 1970, Corexit was deployed by aircraft onto an oil slick leaking from the stricken tanker '']'' in ], Canada.<ref>{{Cite news|url = https://www.newspapers.com/clip/1571624/tanker_arrow_oil_spill_corexit_use/|title = Oil spreads|date = 1970-02-09|access-date = 2015-03-08|newspaper = The Ottawa Journal}}</ref> A month later, ] used Corexit and another chemical dispersant called Cold Clean on and beneath an oil platform off the Louisiana coast during a spill in the Gulf of Mexico.<ref>{{Cite news|url = https://www.newspapers.com/clip/1571638/louisiana_oil_spill_corexit_use/|title = One more Louisiana well capped|date = 1970-03-25|access-date = 2015-03-08|newspaper = Arizona Republic}}</ref> Corexit 9527 was applied to spilled oil in ] in August 1984 but was said to have failed.<ref>{{Cite news|url = https://www.newspapers.com/clip/1571932/coordinator_says_fed_aid_to_replace/|title = Coordinators says Fed aid to replace sand not justified|last = Kirkpatrick|first = Joel|date = 1984-08-30|access-date = 2015-03-08|newspaper = The Galveston Daily News}}</ref> 2,000 gallons of Corexit was air-dropped onto oil which leaked from the SS ''Puerto Rican'' as it sank off ] later that year.<ref>{{Cite news|url = https://www.newspapers.com/clip/1571955/ss_peurto_rican_oil_spill_account/|title = Tank from ship towed into port|date = 1984-11-06|access-date = 2015-03-08|newspaper = Santa Cruz Sentinel}}</ref>

=== 1989–2015 ===
Corexit 9580 was used during the 1989 ] disaster in Alaska. Corexit 7764 and Corexit 9527 were both used during the 1992 ] in ].<ref>Page J. R. "Report on the oil spill from the tanker "Era" at Port Bonython and on the pollution response operations – Report No: DMH 1594/92" ''The South Australian State Committee of the National Plan to Combat Pollution of the Sea by Oil'', South Australia'' ''(1992)''.''</ref> 45,000 litres of Corexit 9500 and 9527 were used in the response to the ] off Australia's north-west shelf in 2009 and 2,000 litres of Corexit 9527 were used after the Chinese bulk carrier '']'' was grounded on Australia's ] in 2010.<ref>{{Cite news|url = http://sixtyminutes.ninemsn.com.au/article.aspx?id=8711153|title = Crude solution|last = Townsend|first = Jo|date = 2013-08-23|access-date = 2014-12-06|publisher = 60 Minutes|archive-url = https://web.archive.org/web/20141208124013/http://sixtyminutes.ninemsn.com.au/article.aspx?id=8711153|archive-date = 2014-12-08|url-status = dead}}</ref> Corexit EC9500A and Corexit EC9527A were used during the 2010 ].<ref>{{Cite web|url=https://www.fda.gov/downloads/Food/RecallsOutbreaksEmergencies/UCM250307.pdf|title=Exposure of Oysters, Crabs, Shrimp, and Red Snapper to Corexit 9500:<!-- Bot generated title -->|website=] }}</ref><ref>{{Cite web|url=https://www.biologicaldiversity.org/programs/public_lands/energy/dirty_energy_development/oil_and_gas/gulf_oil_spill/dispersants.html|title=Dispersants|website=www.biologicaldiversity.org}}</ref><ref name="Eilperin" /><ref>{{Cite web|url=https://www.nytimes.com/gwire/2010/05/13/13greenwire-less-toxic-dispersants-lose-out-in-bp-oil-spil-81183.html|title=''New York Times'', "less toxic dispersants lose out in BP oil spill cleanup", May 13, 2010|website=] }}</ref>

More recently, Corexit has been used in ]. In July 2014, a video released by ] alleged that Corexit 9500 had been used in response to the ], where 8,000 barrels of oil leaked into the ]. The President of ], Khalid Hassanali denied this claim but confirmed that Corexit had been used one mile off-shore near ].<ref>{{Cite news|url = http://www.guardian.co.tt/news/2014-11-22/wake-threats-over-petrotrin-oil-spill-security-increased|title = In wake of threats over Petrotrin oil spill- Security increased|last = Ragoonath|first = Reshma|date = 2014-11-22|access-date = 2014-11-23|newspaper = Trinidad & Tobago Guardian}}</ref>

The use of Corexit is approved in the US by the ] (EPA).<!--<ref name="GuarinoCSM2" />--> This decision was called into question in 2013 following a report by the ] alleging "devastating long-term effects on human health and the Gulf of Mexico ecosystem" stemming from the use of Corexit.<ref name="autogenerated82"></ref><ref name="autogenerated62">{{Cite web|url=https://www.motherjones.com/politics/2013/04/corexit-bp-oil-spill-cover-gulf-mexico-health-and-environment-risk/|title=Why Is the Toxic Dispersant Used After BP's Gulf Disaster Still the Cleanup Agent of Choice in the US?}}</ref>

Of the eight European countries in the ], France, Germany, and the Netherlands have provisions to use Corexit 9500 in an oil spill. Belgium and Norway do not have lists of approved dispersants, but Belgium has a stockpile of Corexit 9527. The UK and Denmark keep lists of approved dispersants and have not approved of Corexit. Sweden does not use dispersant at all.<ref name="Bonn Agreement Dispersants2">{{Cite web|url=http://www.bonnagreement.org/eng/html/counter-pollution_manual/chapter23_dispersants.htm|title=Bonn Agreement Dispersants|access-date=2014-04-10|archive-url=https://web.archive.org/web/20140413145752/http://www.bonnagreement.org/eng/html/counter-pollution_manual/chapter23_dispersants.htm|archive-date=2014-04-13|url-status=dead}}</ref>

===Deepwater Horizon oil spill===
Approximately one week following the incident, subsidiaries of BP formally requested Nalco Company (an indirect subsidiary of Nalco Holding Company) to supply large quantities of Corexit 9500. Corexit 9500 was listed on the U.S. EPA National Contingency Plan Product Schedule and authority and direction for its use was provided by responding federal agencies. Nalco immediately provided available quantities of Corexit and increased production to supply the product to BP’s subsidiaries.<ref name=":1">{{Cite book|title = Nalco 2010 Annual Report|publisher = Nalco Holding Company|year = 2010|pages = 109|url = http://www.nalco.com/documents/Annual-Reports/Nalco_2010_Annual_Report.pdf}}</ref>

On May 19, 2010 the EPA gave BP 24 hours to choose less toxic alternatives to Corexit, selected from the list of EPA-approved dispersants on the National Contingency Plan Product Schedule,<ref name="Environmental Protection Agency">{{cite news |url=http://www.epa.gov/emergencies/content/ncp/product_schedule.htm |title=National Contingency Plan Product Schedule |publisher=Environmental Protection Agency |date=2010-05-13 |access-date=2010-05-21}}</ref> and begin applying them within 72 hours of EPA approval of their choices; or, if BP could not find an alternative, to provide a report on the alternative dispersants investigated and reasons for their rejection.<ref>{{Cite web|url=http://www.epa.gov/bpspill/dispersants/directive-addendum2.pdf|title=Dispersant Monitoring and Assessment Directive - Addendum 2}}</ref> BP took the latter option, sending its report the next day.<ref>{{Cite web|url=http://www.epa.gov/bpspill/dispersants/5-21bp-response.pdf|title=BP response to EPA Monitoring and Assessment Directive - Addendum 2}}</ref> BP's response to dispersant alternatives was judged to be deficient by both the EPA and the US Coast Guard, requiring EPA to perform its own analysis on the relative toxicity of dispersants. Their peer-reviewed conclusions on August 2, 2010 found that Corexit 9500A was generally neither more nor less toxic than the other available dispersants, and that dispersant-oil mixtures were not generally more nor less toxic to test species than oil alone.<ref name="EPAonDispersants2"/> On May 26, the EPA told BP to reduce the use of Corexit by 75%;<ref>{{cite news| url=https://www.nytimes.com/2010/08/01/science/earth/01dispersants.html | work=The New York Times | first=Matthew L. | last=Wald | title=BP Used Much Dispersant Despite E.P.A. Directive of Rarely | date=July 31, 2010}}</ref> surface use was prohibited unless a request for exemption in specific circumstances was granted, while subsurface use was capped at 15,000 gallons per day.<ref>{{Cite web|url=http://www.epa.gov/bpspill/dispersants/directive-addendum3.pdf|title=EPA Dispersant Monitoring and Assessment Directive ‐ Addendum 3}}</ref> After May 26 daily average use decreased 9%, an average of slightly more than 23,000 gallons per day.<ref>{{cite news| url=http://transcripts.cnn.com/TRANSCRIPTS/1007/01/acd.02.html | work=CNN | title=CNN.com}}</ref>

On July 15, 2010, BP announced that it had capped the leaking well, and the application of dispersants by the response effort ceased shortly thereafter.<ref name=":1" />
]

The total used in the event was 1.84 million gallons of Corexit EC9500A and Corexit EC9527A, with roughly 58% sprayed from the air.<ref name=autogenerated4></ref>


==Composition== ==Composition==
The proprietary composition is not public, but the manufacturer's own ] on Corexit EC9527A says the main components are ] and a proprietary ] ] salt with a small concentration of ].<ref name="NALCO, Corexit 9527A Safety Data Sheet">{{cite web |url=http://www.deepwaterhorizonresponse.com/posted/2931/Corexit_EC9527A_MSDS.539295.pdf |title=Safety Data Sheet Product Corexit® EC9527A |work= |accessdate=2010-05-16}}</ref><ref name= ProPublica>{{cite web|title=Chemicals Meant To Break Up BP Oil Spill Present New Environmental Concerns|url=http://www.propublica.org/article/bp-gulf-oil-spill-dispersants-0430|publisher=ProPublica|accessdate=2010-05-07}}</ref> In response to public pressure, the EPA and Nalco released the list of the six ingredients in Corexit 9500, revealing constituents including ], ], and ]s.<ref name="BielloSA"/> Corexit EC9500A is mainly comprised of ] light petroleum distillates, ] and a proprietary organic ] salt.<ref name="urlwww.deepwaterhorizonresponse.com1">{{cite web |url=http://www.deepwaterhorizonresponse.com/posted/2931/Corexit_EC9500A_MSDS.539287.pdf |title=Safety Data Sheet Product Corexit® EC9500A |page=1|publisher=] |accessdate=2010-05-16}}</ref> Propylene glycol is a chemical commonly used as a solvent or moisturizer in pharmaceuticals and cosmetics, and is of relatively low toxicity. 2-Butoxyethanol is more hazardous, and has previously been identified as a causal agent in the health problems experienced by cleanup workers after the 1989 ]. An organic sulfonic acid salt is a synthetic chemical ], that acts as a ] to ] oil and allow its dispersion into water. The identity of the sulfonic acid salt used in both forms of Corexit was disclosed to the EPA in June 2010, as ].<ref>{{cite news|first=Elana |last=Schor |url=http://www.nytimes.com/gwire/2010/06/09/09greenwire-ingredients-of-controversial-dispersants-used-42891.html |title=Ingredients of Controversial Dispersants Used on Gulf Spill Are Secrets No More |publisher=The New York Times |date=2010-6-09}}</ref>


==Effectiveness== ===Corexit 9527===
At the beginning of the Gulf spill, the proprietary composition was not public, but the manufacturer's own ] identified the main components as ] and a proprietary ] ] with a small concentration of ]. Warnings from the Hazardous Substance Fact Sheet for 2-butoxyethanol include: "Cancer Hazard: 2-Butoxy Ethanol may be a ] in humans since it has been shown to cause liver cancer in animals. Many scientists believe there is no safe level of exposure to a carcinogen....Reproductive Hazard: 2-Butoxy Ethanol may damage the developing fetus. There is limited evidence that 2-Butoxy Ethanol may damage the male reproductive system (including decreasing the sperm count) in animals and may affect female fertility in animals".<ref name="AutoBB-125"/><ref>{{cite web|title=Nalco Safety Data Sheet|url=http://lmrk.org/master_ec9527a_msds.539295.pdf |access-date=April 21, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20120306172641/http://lmrk.org/master_ec9527a_msds.539295.pdf |archive-date=March 6, 2012 }}</ref><ref name= ProPublica>{{cite web|title=Chemicals Meant To Break Up BP Oil Spill Present New Environmental Concerns|url=https://www.propublica.org/article/bp-gulf-oil-spill-dispersants-0430|publisher=ProPublica|access-date=2010-05-07|date=2010-04-30}}</ref> 2-butoxyethanol was identified as a causal agent in the health problems experienced by cleanup workers after the 1989 ].<ref name="SchorNYT"/> According to the Alaska Community Action on Toxics, the use of Corexit during the spill caused people "respiratory, nervous system, liver, kidney and blood disorders".<ref name= ProPublica />
The oil film will be dispersed in small droplets which intermix with the seawater. The oil is then not only distributed in two dimensions but is ] in three.


===Corexit 9500===
] (formerly called ]) was 54.7% effective in handling Louisiana ], while ] was 63.4% effective in handling the same oil.<ref>Environmental Protection Agency, NCP Product Schedule, Accessed May 16, 2010, http://www.epa.gov/swercepp/web/content/ncp/products/corex950.htm</ref><ref>Environmental Protection Agency, NCP Product Schedule, Accessed May 16, 2010, http://www.epa.gov/swercepp/web/content/ncp/products/corex952.htm</ref>
In response to public pressure, the EPA and Nalco released the list of the six ingredients in Corexit 9500, revealing constituents including ], ], and ]s.<ref name="BielloSA"/><ref>{{Cite web|url=https://www.ecolab.com/nalco-water|title=Reinventing the Way Water is Managed|website=The Global Leader in Water, Hygiene and Energy &#124; Ecolab}}</ref> Corexit EC9500A is made mainly of ] light petroleum distillates, ] and a proprietary organic ].<ref name="urlwww.deepwaterhorizonresponse.com1">{{cite web |url=http://www.deepwaterhorizonresponse.com/posted/2931/Corexit_EC9500A_MSDS.539287.pdf |title=Safety Data Sheet Product Corexit EC9500A |page=1 |publisher=] |access-date=2010-05-16 |archive-url=https://web.archive.org/web/20100715052550/http://www.deepwaterhorizonresponse.com/posted/2931/Corexit_EC9500A_MSDS.539287.pdf |archive-date=2010-07-15 |url-status=dead }}</ref> According to the New York Times, "Nalco had previously declined to identify the third hazardous substance in the 9500 formula, but EPA's website reveals it to be ], a detergent and common ingredient in laxatives".<ref>{{cite news|first=Elana |last=Schor |url=https://www.nytimes.com/gwire/2010/06/09/09greenwire-ingredients-of-controversial-dispersants-used-42891.html |title=Ingredients of Controversial Dispersants Used on Gulf Spill Are Secrets No More |work=The New York Times |date=2010-06-09}}</ref> Environmentalists also pressured NALCO to reveal to the public what concentrations of each chemical are in the product; NALCO considered such information a ], but shared it with the EPA.<ref name="MulkernNYT">{{Cite news
|url= https://www.nytimes.com/gwire/2010/06/25/25greenwire-maker-of-controversial-dispersant-used-in-gulf-94328.html
|author=Anne Mulkern
|title=Maker of Controversial Dispersant Used in Gulf Oil Spill Hires Top Lobbyists
|date=June 25, 2010
|work=]
|access-date=June 25, 2010
}}</ref>


==Toxicity== ==Toxicity==
]
<!-- LACK OF DATA -->
The relative toxicity of Corexit and other dispersants are difficult to determine due to a scarcity of scientific data.<ref name="BielloSA"/> The manufacturer's safety data sheet states "No toxicity studies have been conducted on this product," and later concludes "The potential human hazard is: Low."<ref name="urlwww.deepwaterhorizonresponse.com5-6">{{cite web |url=http://www.deepwaterhorizonresponse.com/posted/2931/Corexit_EC9500A_MSDS.539287.pdf |title=Safety Data Sheet Product Corexit® EC9500A |pages=5–6|publisher=] |accessdate=June 11, 2010}}</ref>


Corexit is banned in the United Kingdom due to concerns about possible adverse health effects on people using it.<ref name="ajm05014">{{cite journal |title=Health Consequences among Subjects Involved in Gulf Oil Spill Clean-up Activities |first1=M. A.|last1=D'Andrea |first2=G. K. |last2=Reddy |date=November 2013 |journal=The American Journal of Medicine |volume=126 |issue=11 |pages=966–974 |doi=10.1016/j.amjmed.2013.05.014 |pmid=24050487 |doi-access=free}}</ref>
<!-- HUMANS -->
According to the Alaska Community Action on Toxics, the use of Corexit during the Exxon Valdez oil spill caused "respiratory, nervous system, liver, kidney and blood disorders" in people.<ref name= ProPublica /> 9527A is also hazardous for humans: 'May cause injury to red blood cells (hemolysis), kidney or the liver'.<ref>{{cite web|url=http://www.piersystem.com/posted/2931/Corexit_EC9527A_MSDS.539295.pdf|title=Material Safety Data Sheet: Corexit EC9527A|date=May 11, 2010|publisher=NALCO|accessdate=May 30, 2010}}</ref>


Prior to the 2010 Gulf spill, the majority of studies performed on Corexit tested for effectiveness in dispersing oil, rather than for ].<ref>{{Cite web|url=https://al.com/al/2010/05/oil_spill_dispersants_could_be.html|title=Oil dispersants used in Gulf of Mexico spill causing alarm|first=Dennis|last=Pillion|date=May 17, 2010|website=al}}</ref> The manufacturer's safety data sheet states "No toxicity studies have been conducted on this product," and later concludes "The potential human hazard is: Low."<ref name="urlwww.deepwaterhorizonresponse.com5-6">{{cite web |url=http://www.deepwaterhorizonresponse.com/posted/2931/Corexit_EC9500A_MSDS.539287.pdf |title=Safety Data Sheet Product Corexit EC9500A |pages=5–6 |publisher=] |access-date=June 11, 2010 |archive-url=https://web.archive.org/web/20100715052550/http://www.deepwaterhorizonresponse.com/posted/2931/Corexit_EC9500A_MSDS.539287.pdf |archive-date=July 15, 2010 |url-status=dead }}</ref> According to the manufacturer's website, workers applying Corexit should wear breathing protection and work in a ventilated area.<ref>{{Cite news
According to the EPA, Corexit is more toxic than dispersants made by several competitors and less effective in handling southern Louisiana crude.<ref>, '']'', May 13, 2010</ref> On May 20, 2010, the EPA ordered ] to look for less toxic alternatives to Corexit, and later ordered BP to stop spraying dispersants, but BP responded that it thought that Corexit was the best alternative and continued to spray it.<ref name="BielloSA"/>
|url=http://ac360.blogs.cnn.com/2010/06/10/how-will-the-oil-spill-affect-my-health/
|author=Sanjay Gupta
|date=June 10, 2010
|title=Anderson Cooper 360: Blog Archive - How will the oil spill affect my health?
|work=cnn.com
|access-date=June 25, 2010
|archive-date=March 2, 2012
|archive-url=https://web.archive.org/web/20120302090702/http://ac360.blogs.cnn.com/2010/06/10/how-will-the-oil-spill-affect-my-health/
|url-status=dead
}}</ref>

Compared with 12 other dispersants listed by the ], Corexit 9500 and 9527 are either similarly toxic or 10 to 20 times more toxic.<ref name="GuarinoCSM"/> In a preliminary EPA study of eight different dispersants, Corexit 9500 was found to be less toxic to some marine life than other dispersants and to break down within weeks, rather than settling to the bottom of the ocean or collecting in the water.<ref name="CNNBreakup"/> None of the eight dispersants tested were "without toxicity", according to an EPA administrator. During the 2010 spill, the ecological effect of mixing the dispersants with oil was unknown, as was the toxicity of the breakdown products of the dispersant.<ref name="CNNBreakup"/>

Rhode Island Sen. ] said the EPA was not prepared to responsibly authorize BP's use of Corexit, but did so anyway. He noted that manufacturers could nominate themselves to EPA's list of approved dispersants. Although they had to provide data on both efficacy and toxicity, there was no official toxicity limit to bar approval.<ref>{{Cite web|url=http://www.nola.com/news/gulf-oil-spill/index.ssf/2010/08/epa_official_defends_role_of_d.html|title=EPA official defends role of dispersants in Gulf of Mexico oil spill response &#124; NOLA.com<!-- Bot generated title -->}}</ref>

Chemist ] expressed her concern about the danger of the Corexit-crude mixture, telling ] investigators, “The short-term health symptoms include ]s, ]es, cardiovascular impacts, gastrointestinal impacts, and short-term loss of memory....long-term impacts include ], decreased lung function, liver damage, and kidney damage.”<ref name=autogenerated4 />


<!-- WILDLIFE --> <!-- WILDLIFE -->
Nalco spokesman Charlie Pajor said that oil mixed with Corexit is "more toxic to marine life, but less toxic to life along the shore and animals at the surface" because the dispersant allows the oil to stay submerged below the surface of the water.<ref name="DailyHerald"/> Corexit causes oil to form into small droplets in the water; fish may be harmed when they eat these droplets.<ref name="Rosenwaks"/> According to its ], Corexit may also ], remaining in the flesh and building up over time.<ref name="RialesWKRG"/> Thus predators who eat smaller fish with the toxin in their systems may end up with much higher levels in their flesh.<ref name="Rosenwaks"/> The influence of Corexit on microbiological communities is a topic of ongoing research.<ref>Fulmer, P. A.; Hamdan, L. J.: , AGU Fall Meeting Abstracts, December 2010</ref>
Reportedly Corexit is toxic to marine life and helps keep spilled oil submerged. The quantities used in the Gulf will create 'unprecedented underwater damage to organisms.'<ref name="ind30510">{{cite news|url=http://www.independent.co.uk/news/world/americas/oil-spill-creates-huge-undersea-dead-zones-1987039.html|title=Oil spill creates huge undersea 'dead zones'|last=Dugan|first=Emily|date=May 30, 2010|publisher=The Independent|accessdate=May 30, 2010}}</ref>


<!-- HUMANS -->
Petroleum distillates, a major component of Corexit accounting for 10–30% by volume, are known to cause cancer in animals.<ref name="BielloSA"/>
<!-- 9527 -->
Corexit 9527, considered by the EPA to be an ], is stated by its manufacturer to be potentially harmful to ]s, the ]s and the ], and may irritate eyes and skin.<ref>{{Cite web|url=https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+7838|title=Corexit 9527 - National Library of Medicine HSDB Database|website=toxnet.nlm.nih.gov}}</ref><ref name="DuBoisCNN">{{Cite news
|url=https://money.cnn.com/2010/06/14/news/companies/nalco_macondo_bp_spill.fortune/
|title=Company profile of NALCO, maker of Corexit for BP oil spill
|author=Shelley DuBois
|date=June 15, 2010
|publisher=Fortune
|work=cnn.com
|access-date=June 25, 2010
|archive-url=https://web.archive.org/web/20110514164223/https://money.cnn.com/2010/06/14/news/companies/nalco_macondo_bp_spill.fortune/
|archive-date=May 14, 2011
|url-status=dead
}}</ref><ref>{{cite web|url=http://www.piersystem.com/posted/2931/Corexit_EC9527A_MSDS.539295.pdf|title=Material Safety Data Sheet: Corexit EC9527A|quote=may cause injury to red blood cells (hemolysis), kidney or the liver|date=May 11, 2010|publisher=NALCO|access-date=May 30, 2010}}</ref>


<!--9500 -->
Corexit 9500 breaks down in 28 days.<ref name="BielloSA"/>
Like 9527, 9500 can cause ] (rupture of blood cells) and may also cause internal bleeding.<ref name="Rosenwaks"/> According to BP data, 20 percent of offshore workers had levels of 2-Butoxyethanol two times higher than the level certified as safe by the Occupational Safety and Health Administration.<ref name=autogenerated4 />


During a Senate hearing on the use of dispersants, Senator ] asked EPA administrator ] whether Corexit use should be banned, stating she didn't want dispersants to be "the ] of this oil spill".<ref>{{Cite web|url=http://www.courthousenews.com/2010/07/15/28874.htm|title=Courthouse News Service<!-- Bot generated title -->}}</ref><ref>{{Cite web|url=https://www.govinfo.gov/content/pkg/CHRG-111shrg63179/html/CHRG-111shrg63179.htm|title=- REVIEW OF THE USE OF DISPERSANTS IN RESPONSE TO THE DEEPWATER HORIZON OIL SPILL|website=www.govinfo.gov}}</ref><ref>{{Cite web|url=https://www.c-span.org/video/?294897-2/dispersants-gulf-oil-spill-researchers-panel|title=Use of Dispersants in Gulf Oil Spill, Researchers Panel &#124; C-SPAN.org|website=www.c-span.org}}</ref>
==Alternatives==
UK authorities have an approved list of products which must pass both "sea/beach" and "rocky shore" laboratory toxicity tests, following a review of approval procedures over a decade ago.<ref name="mmo510">{{cite document|url=http://www.marinemanagement.org.uk/protecting/pollution/documents/approval_approved_products.pdf|title=Oil spill treatment products approved for use in the United Kingdom|date=May 18, 2010|publisher=Marine Management Organisation|accessdate=June 13, 2010}}</ref> Corexit did not pass the rocky shore test when submitted for renewal of its inclusion on the list, and was dropped. Although it has been omitted from the approved list since 1998, existing stocks which pre-date the removal may be permitted for use away from rocky shorelines, subject to prior approval.


According to a NALCO manual obtained by ], Corexit 9527 is an “eye and skin irritant. Repeated or excessive exposure ... may cause injury to red blood cells (hemolysis), kidney or the liver.” The manual adds: “Excessive exposure may cause central nervous system effects, nausea, vomiting, anesthetic or narcotic effects.” It advises, “Do not get in eyes, on skin, on clothing,” and “Wear suitable protective clothing.” For Corexit 9500 the manual advised, “Do not get in eyes, on skin, on clothing,” “Avoid breathing vapor,” and “Wear suitable protective clothing.” Neither the protective gear, nor the manual were distributed to Gulf oil spill cleanup workers, according to ] requests obtained by GAP.<ref name=autogenerated4 />
Alternative dispersants which are approved by the EPA are listed on the National Contingency Plan Product Schedule<ref name="Environmental Protection Agency"/> and rated for their toxicity and effectiveness.<ref>{{cite article |url=http://www.epa.gov/emergencies/content/ncp/tox_tables.htm#dispersants |title=National Contingency Plan Product Schedule Toxicity and Effectiveness Summaries |publisher=Environmental Protection Agency |date=May 13, 2010 |accessdate=May 21, 2010}}</ref>

A study of 247 BP oil spill clean-up workers released in September 2013 by the ] showed the workers were at an increased risk of developing cancer, leukemia and other illnesses. The study concluded that "clean-up workers exposed to the oil spill and dispersant experienced significantly altered blood profiles, liver enzymes, and somatic symptoms."<ref name="ajm05014" />

===Studies===
{{primary sources|section|date=October 2023}}
Alabama researchers found that the dispersant killed ] and disrupted the Gulf of Mexico's ], noting that it is "like the middle part of the food chain has been taken away".<ref>{{Cite web|url=http://www.nola.com/news/gulf-oil-spill/index.ssf/2012/07/bp_oil_spill_dispersants_may_h.html|title=BP oil spill dispersants may have hurt Gulf of Mexico food chain, study finds &#124; NOLA.com<!-- Bot generated title -->}}</ref>

In late 2012, a study from ] and ] in ''Environmental Pollution journal'' reported that Corexit used during the BP oil spill had increased the ] of the oil by up to 52 times. The study looked at the effects of the oil–Corexit combination on ], which form the base of the food chain. Georgia Tech lab professor Terry Snell said, "There is a synergistic interaction between crude oil and the dispersant that makes it more toxic". He said the addition of Corexit to the gulf spill "probably put a big dent in the planktonic food web for some extended period of time, but nobody really made the measurements to figure out the impact."<ref name="autogenerated3"/><ref name=MSNBC52>{{cite web|title=Dispersant makes oil from spills 52 times more toxic|url=https://www.nbcnews.com/id/wbna50032789|work=MSNBC|access-date=17 April 2014}}</ref><ref>{{cite web|title=Crude Solution|url=http://climatestate.com/2013/08/27/crude-solution-bps-corexit-on-60-minutes/|work=Australian 60 Minutes|access-date=5 April 2014}}</ref><ref>{{Cite web|url=https://www.sciencedaily.com/releases/2012/11/121130110518.htm|title=Gulf of Mexico clean-up makes 2010 spill 52-times more toxic; Mixing oil with dispersant increased toxicity to ecosystems|website=ScienceDaily}}</ref> The leader of the study, Roberto Rico-Martinez (UAA), said "Dispersants are pre-approved to help clean up oil spills and are widely used during disasters....but we have a poor understanding of their toxicity. Our study indicates the increase in toxicity may have been greatly underestimated following the Macondo well explosion." Snell commented: "What remains to be determined is whether the benefits of dispersing the oil by using Corexit are outweighed by the substantial increase in toxicity of the mixture...Perhaps we should allow the oil to naturally disperse. It might take longer, but it would have less toxic impact on marine ecosystems."<ref name=autogenerated3 /> On their own, oil and Corexit were found to be equally toxic.<ref name=HuffPoSilverside52X></ref><ref>{{Cite web|url=https://www.livescience.com/25159-oil-dispersant-increases-toxicity.html|title=Dispersant Makes Oil 52 Times More Toxic|first1=Douglas Main |last1=November 30|first2=2012 12:55pm|last2=ET|website=Live Science|date=30 November 2012 }}</ref>

A study released by ] and ], Netherlands in November 2012, found Corexit made oil sink faster and more deeply into the beaches, and possibly ] supplies. The researchers found that Corexit 9500A allowed the toxic ] (]) to permeate sand where, due to a lack of sunlight, ] is slowed. The authors explained, "The causes of the reduced PAH retention after dispersant application has several reasons: 1) the dispersant transforms the oil containing the PAHs into small ] that can penetrate through the interstitial space of the sand. 2) the coating of the oil particles produced by the dispersant reduces the ] to the sand grains, 3) saline conditions enhance the ] of dispersant to sand surfaces, thereby reducing the sorption of oil to the grains".<ref name=autogenerated2>{{Cite journal|title=Dispersants as Used in Response to the MC252-Spill Lead to Higher Mobility of Polycyclic Aromatic Hydrocarbons in Oil-Contaminated Gulf of Mexico Sand|first1=Markus|last1=Huettel|first2=Alissa|last2=Zuijdgeest|date=November 27, 2012|journal=PLOS ONE|volume=7|issue=11|pages=e50549|doi=10.1371/journal.pone.0050549|pmid=23209777|pmc=3507788|bibcode = 2012PLoSO...750549Z|doi-access=free}}</ref>

A 2012 study clearly suggests that Corexit is highly toxic to early life stages of coral.<ref>{{Cite web|url=https://www.tampabay.com/news/environment/wildlife/deepwater-horizon-oil-dispersant-toxic-to-coral-in-keys/1269717|title=Deepwater Horizon oil, dispersant toxic to coral in Keys|date=January 9, 2013|website=Tampa Bay Times}}</ref> From the paper, "Even at a low concentration (0.86 ppm) of oil-dispersant mixture diluted over 96 hours, most of the ] did not survive".<ref>{{Cite journal|title=Toxicity of Deepwater Horizon Source Oil and the Chemical Dispersant, Corexit® 9500, to Coral Larvae|first1=Kim B.|last1=Ritchie|first2=Allison|last2=Miller|first3=Erin|last3=Pulster|first4=Daniel|last4=Gillon|first5=Dana L.|last5=Wetzel|first6=Gretchen|last6=Goodbody-Gringley|date=January 9, 2013|journal=PLOS ONE|volume=8|issue=1|pages=e45574|doi=10.1371/journal.pone.0045574|pmid=23326298|pmc=3541341|bibcode = 2013PLoSO...845574G|doi-access=free}}</ref>

Studies from Florida showed toxic effects of the oil and Corexit mixture on ] as well as on larger species, including conch, oysters and shrimp.<ref name="autogenerated9">{{Cite web|url=https://www.heraldtribune.com/article/20110530/News/605199449|title=Did BP's oil-dissolving chemical make the spill worse?|first=KATE|last=SPINNER|website=Sarasota Herald-Tribune}}</ref>

] released preliminary results of their study "State of the Beach"<ref>{{Cite web |url=http://surfrider.org/images/uploads/publications/Corexit_Connections.pdf |title=Archived copy |access-date=2013-02-01 |archive-date=2013-01-18 |archive-url=https://web.archive.org/web/20130118020221/http://www.surfrider.org/images/uploads/publications/Corexit_Connections.pdf |url-status=dead }}</ref> in which they found that Corexit appears to make it tougher for microbes to digest the oil. Organic pollutants (]s) stay above ] levels by ] and ] standards owing to inhibition by Corexit of the microbial degradation of hydrocarbons in crude oil. Through the use of 'newly developed' UV light equipment, researchers were able to detect PAHs in sand and on human skin. Corexit, they said, allows these toxins to be absorbed into the skin and cannot be wiped off. The mixture of Corexit and crude is absorbed into wet skin faster than dry.<ref name=autogenerated5>{{Cite web|url=https://www.motherjones.com/politics/2012/04/microbes-arent-eating-oil-gulf-beaches-thanks-corexit-dispersant/|title=BP's Corexit Oil Tar Sponged Up by Human Skin}}</ref>

In 2012, researchers for the ] Department of Natural Resources found evidence of petroleum compounds and Corexit components in the eggs of nesting ] that had migrated to the Gulf of Mexico and back to Minnesota. Because Corexit is an ], researchers said the chemicals can disrupt hormone balance and affect embryo development.<ref>{{Cite web|url=https://www.mprnews.org/story/2012/05/16/environment/oil-residue-found-on-pelicans|title=BP oil spill residue found on pelicans in Minn. &#124; MPR News|website=www.mprnews.org}}</ref><ref>{{cite web|url=http://minnesota.publicradio.org/display/web/2012/11/28/environment/pelican-gulf-of-mexico-oil-contaminant |title=Tests suggest Minn. pelicans exposed to oil contaminants in Gulf &#124; Minnesota Public Radio News |publisher=Minnesota.publicradio.org |date=2012-11-28 |access-date=2013-04-22}}</ref>

Toxins in the Corexit–oil mixture (PAHs) were found to permeate human skin at an accelerated pace due to the presence of the solvent.{{citation needed|date=July 2019}}

When oil is ], it is distributed in three dimensions (in the water column) rather than just two (on the surface). USF scientists found that the untested undersea application of the dispersant created abundant oil plumes in the middle of the Gulf of Mexico.<ref>{{Cite web|url=http://www.tampabay.com/news/environment/water/usf-scientists-confirm-underwater-plumes-came-from-bp-spill/1110673|title=USF scientists confirm underwater plumes came from BP spill – Tampa Bay Times<!-- Bot generated title -->|access-date=2012-12-18|archive-url=https://web.archive.org/web/20130409232950/http://www.tampabay.com/news/environment/water/usf-scientists-confirm-underwater-plumes-came-from-bp-spill/1110673|archive-date=2013-04-09|url-status=dead}}</ref><ref>{{cite news| url=https://www.theguardian.com/environment/2010/may/16/gulf-oil-spill-bp | location=London | work=The Guardian | first=Ed | last=Pilkington | title=Submerged oil plumes suggest gulf spill is worse than BP claims | date=May 16, 2010}}</ref> In 2013 it was reported that everywhere along the track that a plume had drifted, a massive die-off of benthic ] was left in its wake.<ref>{{Cite web|url=https://www.tampabay.com/news/environment/water/gulf-oil-spill-killed-millions-of-microscopic-creatures-at-base-of-food/2113157|title=Three years after BP oil spill, USF research finds massive die-off|date=April 4, 2013|website=Tampa Bay Times}}</ref>

==Effectiveness==
According to the EPA, Corexit EC9500A (formerly "Corexit 9500") was 54.7% effective, while Corexit EC9527A was 63.4% effective in the dispersion of Louisiana ].<ref>{{Cite web|url=http://www.epa.gov/swercepp/web/content/ncp/products/corex950.htm|title=Environmental Protection Agency, NCP Product Schedule, Accessed May 16, 2010}}</ref><ref>{{Cite web|url=http://www.epa.gov/swercepp/web/content/ncp/products/corex952.htm|title=Environmental Protection Agency, NCP Product Schedule, Accessed May 16, 2010}}</ref> The EPA lists 12 other dispersants as being more effective in dealing with oil in a way that is safe for wildlife.<ref name="GuarinoCSM"/><ref>{{cite web
|url=http://www.epa.gov/bpspill/reports/ComparativeToxTest.Final.6.30.10.pdf
|title=Comparative Toxicity of Eight Oil Dispersant Products on Two Gulf of Mexico Aquatic Test Species
|author1=Michael J. Hemmer |author2=Mace G. Barron |author3=Richard M. Greene |date=June 30, 2010
|access-date=August 30, 2011
}}</ref>

Reports from Florida scientists showed Corexit "may not have done its job properly" and that the dispersant "does not seem to facilitate the degradation of the oil" by oil-eating bacteria.<ref name=autogenerated9 /> Evidence from researchers at ] showed Corexit did not degrade as promised. Studies by ] conducted in January 2011 indicated that the 800,000 gallons of Corexit applied at BP's Macondo well-head "did nothing to break up the oil and simply drifted into the ecosystem".<ref name="autogenerated9"/>

In December 2012, a study found that Corexit may have been unnecessary, because the leaking jet of oil at the wellhead had sufficient turbulence to disperse the oil without chemical dispersant.<ref>{{Cite web|url=http://www.labspaces.net/125719/Numerical_study_suggests_subsea_injection_of_chemicals_didn_t_prevent_oil_from_rising_to_sea_surface|title=Numerical study suggests subsea injection of chemicals didn't prevent oil from rising to sea surface|website=www.labspaces.net}}</ref><ref>{{Cite web|url=https://www.scientificamerican.com/article/is-using-dispersants-fighting-pollution-with-pollution/|title=Is Using Dispersants on the BP Gulf Oil Spill Fighting Pollution with Pollution?|first=David|last=Biello|website=Scientific American}}</ref><ref name=gomri/>

==Litigation==
In April 2012, ], the ], and ] filed a lawsuit against the ] and the ], saying the agencies failed to adequately study the chemicals in Corexit and dispersed oil without regard to environmental effects.<ref>{{Cite web |url=https://abc7news.com/archive/8628618/ |title=EPA sued over chemical dispersants used in BP oil spill, 2 years later abc7news.com |access-date=2019-11-18 |archive-url=https://web.archive.org/web/20130718212957/http://abclocal.go.com/kgo/story?section=news%2Flocal%2Fsan_francisco&id=8628618 |archive-date=2013-07-18 |url-status=live }}</ref><ref>{{Cite web|url=http://www.mercurynews.com/breaking-news/ci_20436066/groups-sue-epa-coast-guard-over-dispersants-use|title=Groups sue EPA, Coast Guard over dispersants use - San Jose Mercury News}}</ref>

US District Judge ] in December 2012 dismissed all claims against the manufacturer of Corexit, stating that such claims would become an "obstacle to federal law." Barbier held that Nalco did not determine how and in what quantities Corexit was administered during the Deepwater Horizon oil spill.<ref>{{Cite web|url=http://www.theadvertiser.com/viewart/20121205/NEWS01/212050318/Judge-tosses-claims-against-dispersant-maker|title=Judge tosses claims against dispersant maker |work=The Advertiser}}</ref>

==Criticism==
EPA whistleblower ] gave an interview to ] during the height of the ] news coverage and explained his views on the use of Corexit, saying "EPA now is taking the position that they really don’t know how dangerous it is, even though if you read the label, it tells you how dangerous it is. And, for example, in the ] case, people who worked with dispersants, most of them are dead now. The average death age is around fifty. It’s very dangerous. ... It’s an economic protector of BP, not an environmental protector of the public."<ref name=DemNowKaufman>{{cite web|last=Kaufman|first=Hugh|title=EPA Whistleblower Accuses Agency of Covering Up Effects of Dispersant in BP Oil Spill Cleanup|url=http://www.democracynow.org/2010/7/20/epa_whistleblower_accuses_agency_of_covering|work=Democracy Now video|access-date=5 March 2014}}</ref>

Marine toxicologist ] blamed ] for ] locals with Corexit, which she alleges they used to hide their responsibility.<ref>{{Cite web |url=http://archive.truthout.org/toxic-dispersants-causing-widespread-illness61604 |title=Experts: Health Hazards in Gulf Warrant Evacuations<!-- Bot generated title --> |access-date=2013-01-17 |archive-url=https://web.archive.org/web/20121115061021/http://archive.truthout.org/toxic-dispersants-causing-widespread-illness61604 |archive-date=2012-11-15 |url-status=dead }}</ref> In August 2010 she wrote an open letter to the ] alleging that dispersants were still being used in secret and demanding that the agency take action.<ref>{{cite news|url=https://www.huffingtonpost.com/riki-ott/an-open-letter-to-us-epa_b_697376.html |title=Riki Ott: An Open Letter to US EPA, Region 6 |work=Huffington Post |access-date=2010-09-05 |date=August 27, 2010}}</ref> The letter was published in the ]. Ott told ], "The dispersants used in BP's draconian experiment contain ], such as ] distillates and ]. Solvents dissolve oil, grease, and rubber. It should be no surprise that solvents are also notoriously toxic to people, something the medical community has long known."<ref>{{Cite web|url=https://www.aljazeera.com/news/americas/2012/09/2012959561858341.html|title=US points to 'gross negligence' by BP|website=www.aljazeera.com}}</ref>


==See also== ==See also==
* ] *]


==References== ==References==
{{Reflist|30em|refs=
{{reflist}}
<ref name="DailyHerald">{{cite web |url= http://www.dailyherald.com/story/?id=388026 |title= Nalco dispersant makes oil more toxic to marine life, group says |work=dailyherald.com|date=June 15, 2010 |publisher=Daily Herald |access-date=June 25, 2010}}</ref>
<ref name="BielloSA">{{cite web |url= http://www.scientificamerican.com/article.cfm?id=is-using-dispersants-fighting-pollution-with-pollution |author=David Biello |title=Is Using Dispersants on the BP Gulf Oil Spill Fighting Pollution with Pollution?|publisher= Scientific American |work=scientificamerican.com |date=18 June 2010 |access-date=19 June 2010}}</ref>

<ref name="CNNBreakup">{{Cite news |url= http://www.cnn.com/2010/US/06/30/gulf.oil.dispersants/?hpt=Sbin |title=Dispersants appear to break up in Gulf, EPA says|publisher=CNN|date=June 30, 2010|author=CNN Wire Staff |work=CNN.com |access-date=July 1, 2010}}</ref>

<ref name="Eilperin">{{Cite news |url= http://views.washingtonpost.com/climate-change/post-carbon/2010/05/epa_demands_less_toxic_dispersant.html |title=Post Carbon: EPA demands less-toxic dispersant |author=Juliet Eilperin|newspaper=Washington Post |access-date=June 26, 2010}}</ref>

<ref name="gomri">{{cite web |url=http://gulfresearchinitiative.org/modeling-study-suggests-dispersants-used-at-wellhead-had-marginal-effect-on-oil-reaching-surface-waters/ |title=Modeling Study Suggests Dispersants Used at Wellhead had Marginal Effect on Oil Reaching Surface Waters |publisher=Gulf of Mexico Research Initiative |access-date= March 31, 2014}}</ref>

<ref name="GuarinoCSM">{{cite web |url= http://www.csmonitor.com/USA/2010/0515/In-Gulf-oil-spill-how-helpful-or-damaging-are-dispersants |title=In Gulf oil spill, how helpful – or damaging – are dispersants? |author=Mark Guarino |date= May 15, 2010 |work=CSMonitor.com |publisher=Christian Science Monitor |access-date=26 June 2010 }}</ref>

<ref name="RialesWKRG">{{cite web |url= http://www.wkrg.com/story/21612683/bp-dispersant-getting-independent-lab-test |title=BP Dispersant Getting Independent Lab Test |date=June 18, 2010 |publisher=WKRG News 5 |author=Bill Riales |work=wkrg.com |access-date=April 13, 2014}}</ref>

<ref name="Rosenwaks">{{cite web |url= http://www.torontosun.com/news/world/2010/06/05/14277081.html |author=Gaelin Rosenwaks |date=June 5, 2010 |title=Oil spill's environmental costs | publisher=Toronto Sun |work=torontosun.com |access-date=June 25, 2010}}</ref>

<ref name="SchorNYT">{{Cite news |url= https://www.nytimes.com/gwire/2010/06/09/09greenwire-ingredients-of-controversial-dispersants-used-42891.html |author =Elana Schor |date= June 9, 2010 |title=Ingredients of Controversial Dispersants Used on Gulf Spill Are Secrets No More |work=] |access-date=June 25, 2010}}</ref>

<ref name="AutoBB-125">. (PDF). Retrieved 2011-04-07.</ref>

}}

==External links==
*{{cite web
|url= http://www.thedailybeast.com/newsweek/2013/04/22/what-bp-doesn-t-want-you-to-know-about-the-2010-gulf-spill.html
|title= What BP Doesn't Want You to Know About the 2010 Gulf Spill
| first= Mark |last= Hertsgaard|date= April 22, 2013
|work= ]
|publisher= ]
}}
* "Crude Solution" ] (August 18, 2013) on the health effects of Corexit
**
**
* ] on BP's use of Corexit during the ]
* - video by '']''
*
*
*
*
*

{{Authority control}}


] ]
] ]
] ]

]

Latest revision as of 00:46, 15 August 2024

Oil dispersant
A U.S. Air Force Reserve plane sprays Corexit over the Deepwater Horizon oil spill in the Gulf of Mexico.

Corexit (often styled COREXIT) is a product line of oil dispersants used during oil spill response operations. It is produced by Nalco Holding Company, 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 1,500 m (5,000 ft) 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.

Ownership

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.

Use

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 making 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 about chemical dispersants' toxicity including the costs and benefits of its deployment.

1968–1988

In April 1968, 300 barrels of Corexit were 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.

In February 1970, Corexit was deployed by aircraft onto an oil slick leaking from the stricken tanker Arrow in Nova Scotia, Canada. A month later, Chevron used Corexit and another chemical dispersant called Cold Clean on and beneath an oil platform off the Louisiana coast during a spill in the Gulf of Mexico. Corexit 9527 was applied to spilled oil in Galveston, Texas in August 1984 but was said to have failed. 2,000 gallons of Corexit was air-dropped onto oil which leaked from the SS Puerto Rican as it sank off San Francisco later that year.

1989–2015

Corexit 9580 was used during the 1989 Exxon Valdez oil spill disaster in Alaska. Corexit 7764 and Corexit 9527 were both used during the 1992 Port Bonython oil spill in South Australia. 45,000 litres of Corexit 9500 and 9527 were used in the response to the Montara oil spill off Australia's north-west shelf in 2009 and 2,000 litres of Corexit 9527 were used after the Chinese bulk carrier Shen Neng was grounded on Australia's Great Barrier Reef in 2010. Corexit EC9500A and Corexit EC9527A were used during the 2010 Deepwater Horizon oil spill.

More recently, Corexit has been used in Trinidad. In July 2014, a video released by Anonymous alleged that Corexit 9500 had been used in response to the Petrotrin oil spill, where 8,000 barrels of oil leaked into the Guaracara River. The President of Petrotrin, Khalid Hassanali denied this claim but confirmed that Corexit had been used one mile off-shore near Pointe-à-Pierre.

The use of Corexit is approved in the US by the U.S. Environmental Protection Agency (EPA). This decision was called into question in 2013 following a report by the Government Accountability Project alleging "devastating long-term effects on human health and the Gulf of Mexico ecosystem" stemming from the use of Corexit.

Of the eight European countries in the Bonn Agreement, France, Germany, and the Netherlands have provisions to use Corexit 9500 in an oil spill. Belgium and Norway do not have lists of approved dispersants, but Belgium has a stockpile of Corexit 9527. The UK and Denmark keep lists of approved dispersants and have not approved of Corexit. Sweden does not use dispersant at all.

Deepwater Horizon oil spill

Approximately one week following the incident, subsidiaries of BP formally requested Nalco Company (an indirect subsidiary of Nalco Holding Company) to supply large quantities of Corexit 9500. Corexit 9500 was listed on the U.S. EPA National Contingency Plan Product Schedule and authority and direction for its use was provided by responding federal agencies. Nalco immediately provided available quantities of Corexit and increased production to supply the product to BP’s subsidiaries.

On May 19, 2010 the EPA gave BP 24 hours to choose less toxic alternatives to Corexit, selected from the list of EPA-approved dispersants on the National Contingency Plan Product Schedule, and begin applying them within 72 hours of EPA approval of their choices; or, if BP could not find an alternative, to provide a report on the alternative dispersants investigated and reasons for their rejection. BP took the latter option, sending its report the next day. BP's response to dispersant alternatives was judged to be deficient by both the EPA and the US Coast Guard, requiring EPA to perform its own analysis on the relative toxicity of dispersants. Their peer-reviewed conclusions on August 2, 2010 found that Corexit 9500A was generally neither more nor less toxic than the other available dispersants, and that dispersant-oil mixtures were not generally more nor less toxic to test species than oil alone. On May 26, the EPA told BP to reduce the use of Corexit by 75%; surface use was prohibited unless a request for exemption in specific circumstances was granted, while subsurface use was capped at 15,000 gallons per day. After May 26 daily average use decreased 9%, an average of slightly more than 23,000 gallons per day.

On July 15, 2010, BP announced that it had capped the leaking well, and the application of dispersants by the response effort ceased shortly thereafter.

A worker cleans up oily waste on Elmer's Island, Louisiana, on May 21, 2010

The total used in the event was 1.84 million gallons of Corexit EC9500A and Corexit EC9527A, with roughly 58% sprayed from the air.

Composition

Corexit 9527

At the beginning of the Gulf spill, the proprietary composition was not public, but the manufacturer's own safety data sheet identified the main components as 2-butoxyethanol and a proprietary organic sulfonate with a small concentration of propylene glycol. Warnings from the Hazardous Substance Fact Sheet for 2-butoxyethanol include: "Cancer Hazard: 2-Butoxy Ethanol may be a carcinogen in humans since it has been shown to cause liver cancer in animals. Many scientists believe there is no safe level of exposure to a carcinogen....Reproductive Hazard: 2-Butoxy Ethanol may damage the developing fetus. There is limited evidence that 2-Butoxy Ethanol may damage the male reproductive system (including decreasing the sperm count) in animals and may affect female fertility in animals". 2-butoxyethanol was identified as a causal agent in the health problems experienced by cleanup workers after the 1989 Exxon Valdez oil spill. According to the Alaska Community Action on Toxics, the use of Corexit during the spill caused people "respiratory, nervous system, liver, kidney and blood disorders".

Corexit 9500

In response to public pressure, the EPA and Nalco released the list of the six ingredients in Corexit 9500, revealing constituents including sorbitan, butanedioic acid, and petroleum distillates. Corexit EC9500A is made mainly of hydrotreated light petroleum distillates, propylene glycol and a proprietary organic sulfonate. According to the New York Times, "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". Environmentalists also pressured NALCO to reveal to the public what concentrations of each chemical are in the product; NALCO considered such information a trade secret, but shared it with the EPA.

Toxicity

Sign protesting use of toxic "Corexit" chemical dispersant in the BP Gulf of Mexico oil disaster, at the Bastille Day Tumble, French Quarter, New Orleans

Corexit is banned in the United Kingdom due to concerns about possible adverse health effects on people using it.

Prior to the 2010 Gulf spill, the majority of studies performed on Corexit tested for effectiveness in dispersing oil, rather than for toxicity. The manufacturer's safety data sheet states "No toxicity studies have been conducted on this product," and later concludes "The potential human hazard is: Low." According to the manufacturer's website, workers applying Corexit should wear breathing protection and work in a ventilated area.

Compared with 12 other dispersants listed by the EPA, Corexit 9500 and 9527 are either similarly toxic or 10 to 20 times more toxic. In a preliminary EPA study of eight different dispersants, Corexit 9500 was found to be less toxic to some marine life than other dispersants and to break down within weeks, rather than settling to the bottom of the ocean or collecting in the water. None of the eight dispersants tested were "without toxicity", according to an EPA administrator. During the 2010 spill, the ecological effect of mixing the dispersants with oil was unknown, as was the toxicity of the breakdown products of the dispersant.

Rhode Island Sen. Sheldon Whitehouse said the EPA was not prepared to responsibly authorize BP's use of Corexit, but did so anyway. He noted that manufacturers could nominate themselves to EPA's list of approved dispersants. Although they had to provide data on both efficacy and toxicity, there was no official toxicity limit to bar approval.

Chemist Wilma Subra expressed her concern about the danger of the Corexit-crude mixture, telling GAP investigators, “The short-term health symptoms include acute respiratory problems, skin rashes, cardiovascular impacts, gastrointestinal impacts, and short-term loss of memory....long-term impacts include cancer, decreased lung function, liver damage, and kidney damage.”

Nalco spokesman Charlie Pajor said that oil mixed with Corexit is "more toxic to marine life, but less toxic to life along the shore and animals at the surface" because the dispersant allows the oil to stay submerged below the surface of the water. Corexit causes oil to form into small droplets in the water; fish may be harmed when they eat these droplets. According to its Material safety data sheet, Corexit may also bioaccumulate, remaining in the flesh and building up over time. Thus predators who eat smaller fish with the toxin in their systems may end up with much higher levels in their flesh. The influence of Corexit on microbiological communities is a topic of ongoing research.

Corexit 9527, considered by the EPA to be an acute health hazard, is stated by its manufacturer to be potentially harmful to red blood cells, the kidneys and the liver, and may irritate eyes and skin.

Like 9527, 9500 can cause hemolysis (rupture of blood cells) and may also cause internal bleeding. According to BP data, 20 percent of offshore workers had levels of 2-Butoxyethanol two times higher than the level certified as safe by the Occupational Safety and Health Administration.

During a Senate hearing on the use of dispersants, Senator Lisa Murkowski asked EPA administrator Lisa P. Jackson whether Corexit use should be banned, stating she didn't want dispersants to be "the Agent Orange of this oil spill".

According to a NALCO manual obtained by GAP, Corexit 9527 is an “eye and skin irritant. Repeated or excessive exposure ... may cause injury to red blood cells (hemolysis), kidney or the liver.” The manual adds: “Excessive exposure may cause central nervous system effects, nausea, vomiting, anesthetic or narcotic effects.” It advises, “Do not get in eyes, on skin, on clothing,” and “Wear suitable protective clothing.” For Corexit 9500 the manual advised, “Do not get in eyes, on skin, on clothing,” “Avoid breathing vapor,” and “Wear suitable protective clothing.” Neither the protective gear, nor the manual were distributed to Gulf oil spill cleanup workers, according to FOIA requests obtained by GAP.

A study of 247 BP oil spill clean-up workers released in September 2013 by the American Journal of Medicine showed the workers were at an increased risk of developing cancer, leukemia and other illnesses. The study concluded that "clean-up workers exposed to the oil spill and dispersant experienced significantly altered blood profiles, liver enzymes, and somatic symptoms."

Studies

This section relies excessively on references to primary sources. Please improve this section by adding secondary or tertiary sources.
Find sources: "Corexit" – news · newspapers · books · scholar · JSTOR (October 2023) (Learn how and when to remove this message)

Alabama researchers found that the dispersant killed plankton and disrupted the Gulf of Mexico's food web, noting that it is "like the middle part of the food chain has been taken away".

In late 2012, a study from Georgia Tech and Universidad Autonoma de Aguascalientes in Environmental Pollution journal reported that Corexit used during the BP oil spill had increased the toxicity of the oil by up to 52 times. The study looked at the effects of the oil–Corexit combination on rotifers, which form the base of the food chain. Georgia Tech lab professor Terry Snell said, "There is a synergistic interaction between crude oil and the dispersant that makes it more toxic". He said the addition of Corexit to the gulf spill "probably put a big dent in the planktonic food web for some extended period of time, but nobody really made the measurements to figure out the impact." The leader of the study, Roberto Rico-Martinez (UAA), said "Dispersants are pre-approved to help clean up oil spills and are widely used during disasters....but we have a poor understanding of their toxicity. Our study indicates the increase in toxicity may have been greatly underestimated following the Macondo well explosion." Snell commented: "What remains to be determined is whether the benefits of dispersing the oil by using Corexit are outweighed by the substantial increase in toxicity of the mixture...Perhaps we should allow the oil to naturally disperse. It might take longer, but it would have less toxic impact on marine ecosystems." On their own, oil and Corexit were found to be equally toxic.

A study released by Florida State University and Utrecht University, Netherlands in November 2012, found Corexit made oil sink faster and more deeply into the beaches, and possibly groundwater supplies. The researchers found that Corexit 9500A allowed the toxic components of crude oil (PAHs) to permeate sand where, due to a lack of sunlight, degradation is slowed. The authors explained, "The causes of the reduced PAH retention after dispersant application has several reasons: 1) the dispersant transforms the oil containing the PAHs into small micelles that can penetrate through the interstitial space of the sand. 2) the coating of the oil particles produced by the dispersant reduces the sorption to the sand grains, 3) saline conditions enhance the adsorption of dispersant to sand surfaces, thereby reducing the sorption of oil to the grains".

A 2012 study clearly suggests that Corexit is highly toxic to early life stages of coral. From the paper, "Even at a low concentration (0.86 ppm) of oil-dispersant mixture diluted over 96 hours, most of the mountainous star coral did not survive".

Studies from Florida showed toxic effects of the oil and Corexit mixture on phytoplankton as well as on larger species, including conch, oysters and shrimp.

Surfrider Foundation released preliminary results of their study "State of the Beach" in which they found that Corexit appears to make it tougher for microbes to digest the oil. Organic pollutants (PAHs) stay above carcinogenic levels by NIH and OSHA standards owing to inhibition by Corexit of the microbial degradation of hydrocarbons in crude oil. Through the use of 'newly developed' UV light equipment, researchers were able to detect PAHs in sand and on human skin. Corexit, they said, allows these toxins to be absorbed into the skin and cannot be wiped off. The mixture of Corexit and crude is absorbed into wet skin faster than dry.

In 2012, researchers for the Minnesota Department of Natural Resources found evidence of petroleum compounds and Corexit components in the eggs of nesting pelicans that had migrated to the Gulf of Mexico and back to Minnesota. Because Corexit is an endocrine disruptor, researchers said the chemicals can disrupt hormone balance and affect embryo development.

Toxins in the Corexit–oil mixture (PAHs) were found to permeate human skin at an accelerated pace due to the presence of the solvent.

When oil is dispersed, it is distributed in three dimensions (in the water column) rather than just two (on the surface). USF scientists found that the untested undersea application of the dispersant created abundant oil plumes in the middle of the Gulf of Mexico. In 2013 it was reported that everywhere along the track that a plume had drifted, a massive die-off of benthic foraminifera was left in its wake.

Effectiveness

According to the EPA, Corexit EC9500A (formerly "Corexit 9500") was 54.7% effective, while Corexit EC9527A was 63.4% effective in the dispersion of Louisiana crude. The EPA lists 12 other dispersants as being more effective in dealing with oil in a way that is safe for wildlife.

Reports from Florida scientists showed Corexit "may not have done its job properly" and that the dispersant "does not seem to facilitate the degradation of the oil" by oil-eating bacteria. Evidence from researchers at Florida Institute of Oceanography showed Corexit did not degrade as promised. Studies by Woods Hole Oceanographic Institute conducted in January 2011 indicated that the 800,000 gallons of Corexit applied at BP's Macondo well-head "did nothing to break up the oil and simply drifted into the ecosystem".

In December 2012, a study found that Corexit may have been unnecessary, because the leaking jet of oil at the wellhead had sufficient turbulence to disperse the oil without chemical dispersant.

Litigation

In April 2012, Center for Biological Diversity, the Surfrider Foundation, and Pacific Environment filed a lawsuit against the EPA and the US Coast Guard, saying the agencies failed to adequately study the chemicals in Corexit and dispersed oil without regard to environmental effects.

US District Judge Carl Barbier in December 2012 dismissed all claims against the manufacturer of Corexit, stating that such claims would become an "obstacle to federal law." Barbier held that Nalco did not determine how and in what quantities Corexit was administered during the Deepwater Horizon oil spill.

Criticism

EPA whistleblower Hugh Kaufman gave an interview to Democracy Now during the height of the Deepwater Horizon Oil Spill news coverage and explained his views on the use of Corexit, saying "EPA now is taking the position that they really don’t know how dangerous it is, even though if you read the label, it tells you how dangerous it is. And, for example, in the Exxon Valdez case, people who worked with dispersants, most of them are dead now. The average death age is around fifty. It’s very dangerous. ... It’s an economic protector of BP, not an environmental protector of the public."

Marine toxicologist Riki Ott blamed BP for poisoning locals with Corexit, which she alleges they used to hide their responsibility. In August 2010 she wrote an open letter to the Environmental Protection Agency alleging that dispersants were still being used in secret and demanding that the agency take action. The letter was published in the Huffington Post. Ott told Al Jazeera, "The dispersants used in BP's draconian experiment contain solvents, such as petroleum distillates and 2-butoxyethanol. Solvents dissolve oil, grease, and rubber. It should be no surprise that solvents are also notoriously toxic to people, something the medical community has long known."

See also

References

  1. "Archived copy" (PDF). Archived from the original (PDF) on 2010-06-04. Retrieved 2010-06-26.{{cite web}}: CS1 maint: archived copy as title (link)
  2. "Reinventing the Way Water is Managed". The Global Leader in Water, Hygiene and Energy | Ecolab. Archived from the original on April 11, 2013.
  3. PAUL QUINLAN of Greenwire (2010-05-13). "Less Toxic Dispersants Lose Out in BP Oil Spill Cleanup". The New York Times. Retrieved 2010-06-10.
  4. ^ "Esso develops oil dispersant". The Corpus Christi Caller-Times. 1968-10-09. Retrieved 2015-01-15.
  5. Davies, L.; Daniel, F.; Swannell, R.; Braddock, J. Biodegradability of Chemically-dispersed Oil. Report produced for the Minerals Management Service (MMS), Alaska Department of Environmental Conservation (ADEC) and the United States Coast Guard (USCG). March 2001. http://dec.alaska.gov/spar/perp/r_d/aeat.pdf Archived 2014-06-30 at the Wayback Machine (accessed May 7, 2012)
  6. ^ "EPA Response to BP Spill in the Gulf of Mexico -- Questions and Answers". Archived from the original on August 12, 2010.
  7. ^ Gaelin Rosenwaks (June 5, 2010). "Oil spill's environmental costs". torontosun.com. Toronto Sun. Retrieved June 25, 2010.
  8. ^ David Biello (18 June 2010). "Is Using Dispersants on the BP Gulf Oil Spill Fighting Pollution with Pollution?". scientificamerican.com. Scientific American. Retrieved 19 June 2010.
  9. "Is Using Dispersants on the BP Gulf Oil Spill Fighting Pollution with Pollution?". Scientific American. Retrieved 22 April 2014.
  10. Khan, Amina (September 4, 2010). "Oil dispersant effects remain a mystery". Los Angeles Times.
  11. "VIDEO: Is the BP Oil Spill Cleanup Still Making People Sick?". VICE/HBO. Mother Jones. Retrieved 17 May 2014.
  12. ^ "Gulf of Mexico Clean-Up Makes 2010 Spill 52-Times More Toxic". www.news.gatech.edu.
  13. ^ Is Using Dispersants on the BP Gulf Oil Spill Fighting Pollution with Pollution? Scientific American. Biello, 2010
  14. "Mopping up the seas". The Anniston Star. Anniston, Alabama. 1968-09-23. Retrieved 2015-01-15.
  15. Assessment of the use of dispersants on oil spills in Californian marine waters. S.L. Ross Environmental Research Ltd. 2002. p. 30. Archived from the original on 2015-01-21. Retrieved 2015-01-21.
  16. "Oil pollution fears hit world's nations". Anderson Herald. 1968-08-31. Retrieved 2015-03-08.
  17. Burns, Andrew (1979-07-23). "Oil and the Great Barrier Reef". Woroni. Retrieved 2015-01-21.
  18. Beckman, Robert (1968-05-12). "New formulation. Chemical disperses oil spill; Fish safe". Independent Press-Telegram. Long Beach, California. Retrieved 2015-01-21.
  19. ^ Moore, Dick (1968-12-27). "Editor's scratch pad". The Daily Times. Salisbury, Maryland. Retrieved 2015-03-08.
  20. Amundson, Rod (1968-12-26). "Guppy says yanks moved North Pole". The High Point Enterprise. High Point, North Carolina. Retrieved 2015-03-08.
  21. Hines, William (1969-01-02). "Chemicals break up oil slick". The Times Recorder. Zanesville, Ohio. Retrieved 2015-03-08.
  22. "Chemical firm mixes oil and water successfully". Naugatuck Daily News. Naugatuck, Connecticut. 1968-12-11. Retrieved 2015-03-08.
  23. "New oil dispersant". The Ottawa Journal. 1969-02-08. Retrieved 2015-03-08.
  24. "Oil spreads". The Ottawa Journal. 1970-02-09. Retrieved 2015-03-08.
  25. "One more Louisiana well capped". Arizona Republic. 1970-03-25. Retrieved 2015-03-08.
  26. Kirkpatrick, Joel (1984-08-30). "Coordinators says Fed aid to replace sand not justified". The Galveston Daily News. Retrieved 2015-03-08.
  27. "Tank from ship towed into port". Santa Cruz Sentinel. 1984-11-06. Retrieved 2015-03-08.
  28. Page J. R. "Report on the oil spill from the tanker "Era" at Port Bonython and on the pollution response operations – Report No: DMH 1594/92" The South Australian State Committee of the National Plan to Combat Pollution of the Sea by Oil, South Australia (1992).
  29. Townsend, Jo (2013-08-23). "Crude solution". 60 Minutes. Archived from the original on 2014-12-08. Retrieved 2014-12-06.
  30. "Exposure of Oysters, Crabs, Shrimp, and Red Snapper to Corexit 9500:" (PDF). Food and Drug Administration.
  31. "Dispersants". www.biologicaldiversity.org.
  32. Juliet Eilperin. "Post Carbon: EPA demands less-toxic dispersant". Washington Post. Retrieved June 26, 2010.
  33. "New York Times, "less toxic dispersants lose out in BP oil spill cleanup", May 13, 2010". The New York Times.
  34. Ragoonath, Reshma (2014-11-22). "In wake of threats over Petrotrin oil spill- Security increased". Trinidad & Tobago Guardian. Retrieved 2014-11-23.
  35. Corexit: Deadly Dispersant in Oil Spill Cleanup – Government Accountability Project
  36. "Why Is the Toxic Dispersant Used After BP's Gulf Disaster Still the Cleanup Agent of Choice in the US?".
  37. "Bonn Agreement Dispersants". Archived from the original on 2014-04-13. Retrieved 2014-04-10.
  38. ^ Nalco 2010 Annual Report (PDF). Nalco Holding Company. 2010. p. 109.
  39. "National Contingency Plan Product Schedule". Environmental Protection Agency. 2010-05-13. Retrieved 2010-05-21.
  40. "Dispersant Monitoring and Assessment Directive - Addendum 2" (PDF).
  41. "BP response to EPA Monitoring and Assessment Directive - Addendum 2" (PDF).
  42. Wald, Matthew L. (July 31, 2010). "BP Used Much Dispersant Despite E.P.A. Directive of Rarely". The New York Times.
  43. "EPA Dispersant Monitoring and Assessment Directive ‐ Addendum 3" (PDF).
  44. "CNN.com". CNN.
  45. ^ What BP Doesn’t Want You to Know About the 2010 Gulf Spill – Newsweek and The Daily Beast
  46. Microsoft Word – 0275.doc. (PDF). Retrieved 2011-04-07.
  47. "Nalco Safety Data Sheet" (PDF). Archived from the original (PDF) on March 6, 2012. Retrieved April 21, 2013.
  48. ^ "Chemicals Meant To Break Up BP Oil Spill Present New Environmental Concerns". ProPublica. 2010-04-30. Retrieved 2010-05-07.
  49. Elana Schor (June 9, 2010). "Ingredients of Controversial Dispersants Used on Gulf Spill Are Secrets No More". The New York Times. Retrieved June 25, 2010.
  50. "Reinventing the Way Water is Managed". The Global Leader in Water, Hygiene and Energy | Ecolab.
  51. "Safety Data Sheet Product Corexit EC9500A" (PDF). Nalco. p. 1. Archived from the original (PDF) on 2010-07-15. Retrieved 2010-05-16.
  52. Schor, Elana (2010-06-09). "Ingredients of Controversial Dispersants Used on Gulf Spill Are Secrets No More". The New York Times.
  53. Anne Mulkern (June 25, 2010). "Maker of Controversial Dispersant Used in Gulf Oil Spill Hires Top Lobbyists". The New York Times. Retrieved June 25, 2010.
  54. ^ D'Andrea, M. A.; Reddy, G. K. (November 2013). "Health Consequences among Subjects Involved in Gulf Oil Spill Clean-up Activities". The American Journal of Medicine. 126 (11): 966–974. doi:10.1016/j.amjmed.2013.05.014. PMID 24050487.
  55. Pillion, Dennis (May 17, 2010). "Oil dispersants used in Gulf of Mexico spill causing alarm". al.
  56. "Safety Data Sheet Product Corexit EC9500A" (PDF). Nalco. pp. 5–6. Archived from the original (PDF) on July 15, 2010. Retrieved June 11, 2010.
  57. Sanjay Gupta (June 10, 2010). "Anderson Cooper 360: Blog Archive - How will the oil spill affect my health?". cnn.com. Archived from the original on March 2, 2012. Retrieved June 25, 2010.
  58. ^ Mark Guarino (May 15, 2010). "In Gulf oil spill, how helpful – or damaging – are dispersants?". CSMonitor.com. Christian Science Monitor. Retrieved 26 June 2010.
  59. ^ CNN Wire Staff (June 30, 2010). "Dispersants appear to break up in Gulf, EPA says". CNN.com. CNN. Retrieved July 1, 2010. {{cite news}}: |author= has generic name (help)
  60. "EPA official defends role of dispersants in Gulf of Mexico oil spill response | NOLA.com".
  61. "Nalco dispersant makes oil more toxic to marine life, group says". dailyherald.com. Daily Herald. June 15, 2010. Retrieved June 25, 2010.
  62. Bill Riales (June 18, 2010). "BP Dispersant Getting Independent Lab Test". wkrg.com. WKRG News 5. Retrieved April 13, 2014.
  63. Fulmer, P. A.; Hamdan, L. J.: Effects of COREXIT EC9500A on bacterial communities influenced by the Deepwater Horizon oil spill, AGU Fall Meeting Abstracts, December 2010
  64. "Corexit 9527 - National Library of Medicine HSDB Database". toxnet.nlm.nih.gov.
  65. Shelley DuBois (June 15, 2010). "Company profile of NALCO, maker of Corexit for BP oil spill". cnn.com. Fortune. Archived from the original on May 14, 2011. Retrieved June 25, 2010.
  66. "Material Safety Data Sheet: Corexit EC9527A" (PDF). NALCO. May 11, 2010. Retrieved May 30, 2010. may cause injury to red blood cells (hemolysis), kidney or the liver
  67. "Courthouse News Service".
  68. "- REVIEW OF THE USE OF DISPERSANTS IN RESPONSE TO THE DEEPWATER HORIZON OIL SPILL". www.govinfo.gov.
  69. "Use of Dispersants in Gulf Oil Spill, Researchers Panel | C-SPAN.org". www.c-span.org.
  70. "BP oil spill dispersants may have hurt Gulf of Mexico food chain, study finds | NOLA.com".
  71. "Dispersant makes oil from spills 52 times more toxic". MSNBC. Retrieved 17 April 2014.
  72. "Crude Solution". Australian 60 Minutes. Retrieved 5 April 2014.
  73. "Gulf of Mexico clean-up makes 2010 spill 52-times more toxic; Mixing oil with dispersant increased toxicity to ecosystems". ScienceDaily.
  74. BP oil spill cleanup toxic to key species | Huffington Post
  75. November 30, Douglas Main; ET, 2012 12:55pm (30 November 2012). "Dispersant Makes Oil 52 Times More Toxic". Live Science.{{cite web}}: CS1 maint: numeric names: authors list (link)
  76. Huettel, Markus; Zuijdgeest, Alissa (November 27, 2012). "Dispersants as Used in Response to the MC252-Spill Lead to Higher Mobility of Polycyclic Aromatic Hydrocarbons in Oil-Contaminated Gulf of Mexico Sand". PLOS ONE. 7 (11): e50549. Bibcode:2012PLoSO...750549Z. doi:10.1371/journal.pone.0050549. PMC 3507788. PMID 23209777.
  77. "Deepwater Horizon oil, dispersant toxic to coral in Keys". Tampa Bay Times. January 9, 2013.
  78. Ritchie, Kim B.; Miller, Allison; Pulster, Erin; Gillon, Daniel; Wetzel, Dana L.; Goodbody-Gringley, Gretchen (January 9, 2013). "Toxicity of Deepwater Horizon Source Oil and the Chemical Dispersant, Corexit® 9500, to Coral Larvae". PLOS ONE. 8 (1): e45574. Bibcode:2013PLoSO...845574G. doi:10.1371/journal.pone.0045574. PMC 3541341. PMID 23326298.
  79. ^ SPINNER, KATE. "Did BP's oil-dissolving chemical make the spill worse?". Sarasota Herald-Tribune.
  80. "Archived copy" (PDF). Archived from the original (PDF) on 2013-01-18. Retrieved 2013-02-01.{{cite web}}: CS1 maint: archived copy as title (link)
  81. "BP's Corexit Oil Tar Sponged Up by Human Skin".
  82. "BP oil spill residue found on pelicans in Minn. | MPR News". www.mprnews.org.
  83. "Tests suggest Minn. pelicans exposed to oil contaminants in Gulf | Minnesota Public Radio News". Minnesota.publicradio.org. 2012-11-28. Retrieved 2013-04-22.
  84. "USF scientists confirm underwater plumes came from BP spill – Tampa Bay Times". Archived from the original on 2013-04-09. Retrieved 2012-12-18.
  85. Pilkington, Ed (May 16, 2010). "Submerged oil plumes suggest gulf spill is worse than BP claims". The Guardian. London.
  86. "Three years after BP oil spill, USF research finds massive die-off". Tampa Bay Times. April 4, 2013.
  87. "Environmental Protection Agency, NCP Product Schedule, Accessed May 16, 2010".
  88. "Environmental Protection Agency, NCP Product Schedule, Accessed May 16, 2010".
  89. Michael J. Hemmer; Mace G. Barron; Richard M. Greene (June 30, 2010). "Comparative Toxicity of Eight Oil Dispersant Products on Two Gulf of Mexico Aquatic Test Species" (PDF). Retrieved August 30, 2011.
  90. "Numerical study suggests subsea injection of chemicals didn't prevent oil from rising to sea surface". www.labspaces.net.
  91. Biello, David. "Is Using Dispersants on the BP Gulf Oil Spill Fighting Pollution with Pollution?". Scientific American.
  92. "Modeling Study Suggests Dispersants Used at Wellhead had Marginal Effect on Oil Reaching Surface Waters". Gulf of Mexico Research Initiative. Retrieved March 31, 2014.
  93. "EPA sued over chemical dispersants used in BP oil spill, 2 years later abc7news.com". Archived from the original on 2013-07-18. Retrieved 2019-11-18.
  94. "Groups sue EPA, Coast Guard over dispersants use - San Jose Mercury News".
  95. "Judge tosses claims against dispersant maker". The Advertiser.
  96. Kaufman, Hugh. "EPA Whistleblower Accuses Agency of Covering Up Effects of Dispersant in BP Oil Spill Cleanup". Democracy Now video. Retrieved 5 March 2014.
  97. "Experts: Health Hazards in Gulf Warrant Evacuations". Archived from the original on 2012-11-15. Retrieved 2013-01-17.
  98. "Riki Ott: An Open Letter to US EPA, Region 6". Huffington Post. August 27, 2010. Retrieved 2010-09-05.
  99. "US points to 'gross negligence' by BP". www.aljazeera.com.

External links

Categories: