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Previous by Date: Subject: Re: Impervious Gloves Date: Sun, 12 Sep 2004 21:03:59 EDT Author: Jim Kaufman |
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I've dealt with HSE aspects of using MDI (1) as a prepolymer for polyurethanes in process development, (2) as a two-part industrial coating, and (2) as a packaging foam. I was generally most concerned about using it as a coating - Despite complicated PPE (including air-supplied respirator) and a good paintbooth, there was the concern for the painter becoming allergic to his job. [The epoxy paints have their concerns, also, but less so.] The process development work involved heat, so this was not good either, but did not come up often. It was used routinely, though not constantly, in packaging delicate items for shipment. In my experience, no one became allergic on the job in the 15+ years that I was involved in safety at that facility. A big concern is asthmatic effects. Also known asthmatics can react just by being hyper-reactive. MDI has essentially no warning properties. Fortunately, it has a very low vapor pressure, but it is also a problem as an areosol mist or when heated significantly. As a packaging foam, (the kind used to protect delicate electronic parts, etc, it used to come in plastic carboys (the MDI prepolymer and the polyol separately), which fed a foaming gun. The MDI must be reacted before disposal. [Locally, people in our county have set fire to dumpsters by mishandling it.] - Some of our workers dumped some polyol into some (TOO MUCH) left-over in a carboy and put the lid on. DUH!!!! the pressure built up The cap went before the carboy, and the foam shot right up all the way to the ceiling (about 20 ft up.) More recently, they used packages of "sealed" foam. These come in several sizes, which are kept slightly warmed in a heated storage holder.The chemicals are kept in tough film packages (they look like 4H gloves) which include the 2 parts in separate sections, inside. If you knead and squeeze it right, the inner seal breaks, the foam starts working, and you quickly place the bag into a space you want to seal inside a package. There are some fine holes in the top of the bag for the air to escape as the foam fills the bag. These MUST face up [I had some folks learn to take THIS requirement seriously from sad experience... burst bags and foam on safety glasses (need I say more)] Basically, this is a much better way of handling the foam... very small quantities of chemical, and reasonably well isolated. Also no wastes in carboys and no foam guns and lines to clean. I don't know if this would help your situations, as it may not be sufficiently tight to the bottles.... only as a ! cushion: http://www.sealedair.com/instapak_home.htm Here is a link which includes MSDSs for the 2 parts... Part A is the polymeric MDI http://www.instapakquick.com/products/protective/instapak/quick/instapakquick_works.html - I always found the Sealed-Air folks very helpful. Maybe you could check with them. - At any rate, it strikes me that you could handle this situation best if you did your packaging inside a hood, no matter how you did it .... I get the impression you are not talking about large containers here. - best to all... -Dianne Kidwell Safety & Compliance Manager PierCon Solutions ACTSNYC**At_Symbol_Here**CS.COM wrote: MR: I'll answer in the body of your e-mail: In a message dated 9/8/04 9:09:50 PM Eastern Daylight Time, mrsafetyman**At_Symbol_Here**juno.com writes: > Wow, thanks for the input. The product does have a rather low health hazard > MR: There are two types of Great Stuff Products. The first type is the Great Stuff which says on the can it is for "household use." The other spray can products are Great Stuff Gaps and Cracks, Great Stuff Window Seal, etc. And all of these are available at good hardware outlets that contractors use. Great Stuff Gaps and Cracks contains between 5 and 30% (this alone is a worry) a polymethylene polyphenyl isocyanate CAS # 9016-87-9, that contains 40-50% 4,4'methylene bisphenyl isocyanate CAS# 101-68-8 (MDI). This means that somewhere between 2% and 15% of the product is MDI with a TLV-TWA of 0.005 ppm, Recommendations for air-supplied respirators are on the MSDS because there is no cartridge approved for it without change out schedules and air monitoring. I searched and searched the Dow site and it apparently does not provide the MSDS for the household variety. But according to the National Institutes of Health National Library of Medicine's Household Product Database, the prepolymer is the primary ingredient and only 0.2-0.05% is in the form of MDI. But other countries recognize that the prepolymer is just as toxic as MDI, it just has a lower vapor pressure so exposure should be lower. In England, for example, the occupational exposure to this product would be regulated by the number of isocyanate units on the compound, not the compound to which the units are attached. In the US, if you change the structure of the compound, it is now unregulated and can be labeled without warnings or even "nontoxic" if you choose. This is nuts. But it can explain why a product that contains reactive isocyanate structures has a low toxicity rating. and it is used by three labs I know of to seal bottles as well as many contractors. I > have not heard of an incident yet until now. MR: You won't. Most people use the stuff for a while with no difficulties. It is the people who become sensitized whose lives are ruined or who die. Read about the isocyanates. They are powerful sensitizers and irritants. Some cause cancer, so the effects will not be seen immediately. > contacted Dow and they advised that the product is safe if used > correctly. MR: If you get your hazard data from the people selling the product, then I have a car I want to talk to you about. They have not had any recent litigation as of yet mentioning your incidents. MR: The workers' comp cases involve the employer, not Dow. And do you really think Dow would tell you about any lawsuits pending or settled? Why don't you provide me your snail mail address and I'll send you a long data sheet on the urethanes which mentions some of the incidents of which I am personally aware as a union rep and expert witness. > direct me to actual other data or events that are documented since > this is very enlightening to me. I inspect many facilities as a code > enforcement officer and that is how I saw the processes of corking during a fire > inspection. If i had some hard data, this would enable me to approach those i > know that perform this work. > Thanks for your assistance and input. MR: This is not a mystery--it is a well known problem. How else could the ACGIH set a 0.005 ppm TLV-TWA for MDI? They have to have a PILE of data to set a low TLV or the affected industries will sue them for restriction of trade. Ah, that's the answer to your questions. Get a copy of the ACGIH Documentation of TLVs for MDI. That will put it all in perspective for you better than my data. All the data and references are there. Monona Rossol, M.S., M.F.A., industrial hygienist Arts, Crafts & Theater Safety, Inc. and Safety Officer, United Scenic Artist's, Local 829 International Alliance of Theatrical Stage Employes (IATSE) 181 Thompson St., #23 New York NY 10012-2586 212/777-0062 artscraftstheatersafety.org
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