A currently recommended diary raises the very important concern of health hazards due to mixing Corexit (the dispersant) with oil (the pollutant).
This is a valid concern. However, it is important to correct some areas of potential confusion when talking about Corexit, so I am writing about it here to clarify.
Corexit is basically a detergent. That is why it disperses oil into droplets. It works just like dishwashing detergent.
Corexit was developed to work on oil spills, not dishes. There are at least 4 different formulations of Corexit. I am going to use the EPA technical product bulletins to highlight the differences and the potential hazards.
First: which one is approved and listed for use on the surface?
EC9500A was not relisted. This is probably due in part to the fact that
As stated in MSDS, once it had one, Corexit 9500 can cause central nervous system depression, nausea, and unconsciousness. It can cause liver, kidney damage, and red blood cell hemolysis with repeated or prolonged exposure through inhalation or ingestion according to the MSDS. The threat to human health via exposure is characterized as 'MODERATE'." uspoly.com/dispersit
EC7664A is the one that was re-listed. A major difference between 7664 and the 9500 series is that 7664 is formulated in a solvent containing isopropyl alcohol and water, the others are hydrocarbon solutions. Isopropyl alcohol is not something you would drink (it will blind you), but it is a lot easier to break down in the environment than the alternative solvent. That is a major reason it is approved for this sort of use.
Unlike some of the others, this form has relatively low toxicity when tested with fish. It is less toxic than oil. The toxicity of oil is not enhanced when mixed with it. (see Section VII Toxicity and Effects).
However, there are a few things to worry about here.
- EC 7664A does contain detectable levels of heavy metals.
- Corexit 9500A does have the potential to bioaccumulate.
- Corexit 9500A tends to distribute along the bottom.
The info for 9500A is provided by its Material Safety Data Sheet. I have not been able to locate a Material Safety Data Sheet for 7664A so I am going by the EPA technical product bulletin.
Of particular interest and note is a very informative presentation about this family of products given in March 2004, by Jim Clark of ExxonMobil Research and Engineering.
When he discussed the health hazards the point of his slide was clear:
General Protective Procedures
•Conduct specific product hazard communication/hazard control training
– Review MSDS
• Minimize contact where possible
– Wear personal protective equipment
(nitrile gloves, SaranexTMsuit, chemical goggles)
– Position upwind or sidewind of application
– Promptly wash affected skin
– Decontaminate clothing
- SaranexTM suit
Common Sense!
And he includes this photo:
I do not think it is appropriate or legitimate to pretend that health concerns and proper handling for 7664 should not be compared to 9500, especially in the absence of a Material Safety Data Sheet for 7664. Until there is one to reference, the prudent course of action is to treat 7664 handling the same way you would handle 9500. That is clearly not being done.
Here is what the EC9500A MSDS says about Accidental Release Measures:
PERSONAL PRECAUTIONS :
Restrict access to area as appropriate until clean-up operations are complete. Ensure clean-up is conducted by trained personnel only. Ventilate spill area if possible. Do not touch spilled material. Remove sources of ignition.
Stop or reduce any leaks if it is safe to do so. Have emergency equipment (for fires, spills, leaks, etc.) readily available. Use personal protective equipment recommended in Section 8 (Exposure Controls/Personal Protection). Notify appropriate government, occupational health and safety and environmental authorities.
And what do they recommend in Section 8?
RESPIRATORY PROTECTION :
If significant mists, vapors or aerosols are generated an approved respirator is recommended. An organic vapor cartridge with dust/mist prefilter or supplied air may be used. In event of emergency or planned entry into unknown concentrations a positive pressure, full-facepiece SCBA should be used. If respiratory protection is required, institute a complete respiratory protection program including selection, fit testing, training, maintenance and inspection.
HAND PROTECTION :
Nitrile gloves, Viton# gloves, Polyvinyl alcohol gloves
SKIN PROTECTION :
Wear impervious apron and boots.
EYE PROTECTION :
Wear chemical splash goggles.
HYGIENE RECOMMENDATIONS :
Keep an eye wash fountain available. Keep a safety shower available. If clothing is contaminated, remove clothing and thoroughly wash the affected area. Launder contaminated clothing before reuse.
Updated from the comments: Look at this piece of propaganda showing how "safe" EC9500 is. Note the guy doing the demo is wearing protective glasses, gloves, and a lab coat. He is exercising proper safety precautions. Why? Because it is toxic.
If the following report is correct and 9500 is being sprayed all over the Gulf this is a huge problem. That is one huge release of this compound. The fact it is not accidental doesn't mean you can ignore all the safety precautions. You think the guys in the Gulf are using proper safety precautions? You think people on the shore are?
(h/t to Scarce for finding this)
Given the EPA's own test (cf. Fig 1 and Fig. 9) showing 7664 much less effective at dispersing oil than 9580, I am skeptical that only 7664 is being used. I am concerned that at least to clean the boats, 9580 is possibly being used without proper safety practices. This is important because its Material Safety Data Sheet makes it clear that formulation is not only flammable, more dangerous, but lacks any toxicity data. The reason it is flammable is the solvent used is a volatile organic compound. Imagine cleaning oily scum off a boat using kerosene or gasoline in the hot summer sun and you get a sense of what may be happening here.
Regarding the use of the (relatively) safer 7664A formulation, I am concerned because the application directions are explicit and they may not be following the warnings. The magnitude of the dispersion makes it impossible to avoid aerosols and that is a problem:
VI. RECOMMENDED APPLICATION PROCEDURE
- Application Method:
Spray from boats, aircraft, fire education systems on boats, helicopter buckets, hand-held or backpack sprayers, or from hoses attached to small pumps. COREXIT® EC7664A should be applied in the form of small droplets - never as a fog or mist.
- Concentration/Application Rate:
COREXIT® EC7664A diluted 1-3 percent in water sprayed on the shoreline before the oil comes ashore will protect the beaches, marshes, rocks, etc. from oil contamination. Full strength COREXIT® EC7664A can be sprayed onto the surf which washes the shoreline.
- Conditions for Use:
COREXIT® EC7664A (1-3 percent in water) will protect beaches, marshes, rocks, and other shoreline structures from oil contamination if applied before the oil comes in contact with them. The dilute solution is sprayed on the shoreline area. COREXIT® EC7664A is also useful in washing oil from beaches, sea walls, docks, boats, and spill cleanup equipment. Use a 1-3 percent solution of COREXIT® EC7664A in water, and apply from portable sprayers. If oil deposits are heavy or weathered, a short pre-soak with a hydrocarbon-based shoreline cleaner like COREXIT® EC9580A is recommended.
I'm betting the guys are washing their boats and gear and applying various forumlations of Corexit in ways that enhance their exposure. I wouldn't be surprised if they are inadvertently mixing different formulations to boot.
I'm also betting the people along the coast are breathing aerosols of this which is to be avoided - hence the instruction to apply as drops not fog or mist.
Given the well-documented, and well-known industry standard of proper use and application,the following exchange in an interview with the president of the Louisiana Shrimp Association, Clint Guidry, raises serious concerns about BP's continued wilfull negligence:
AMY GOODMAN: What about respirators? Are people wearing respirators?
CLINT GUIDRY: No, ma’am. Having had prior experience, I know these people. They’re friends. They’re family. I bought respirators, and I brought them down to these people. And when they tried to wear them, the BP representatives on site told them that it wasn’t a dangerous situation, and they didn’t need to wear them, and if they did, they would be taken off the job.
emphasis added
h/t to o the umanity and Vyan for catching this piece of evidence in the interview ... and as always to Amy Goodman for asking the questions the corporate media ignores.