DCHAS-L Archives, Mar 22 2022 - Re: [DCHAS-L] [External] Re: [DCHAS-L] OSHA materials on Karen Wetterhahn's mercury exposure

Now THAT, my dear Sammye, is consistent with what I remember from this period. The problem is chemists sometimes interpreted "rubber gloves" as "thin latex rubber examining gloves" and those are not equivalent. And strangely they seem to feel that all gloves should be made so that dexterity and tactile feelings are preserved. Sometimes that is just not doable and you need to find another way to get the chemical where you want it to go.

And "chemically impervious gloves" was the kind of liability-defensive wording on a lot of MSDSs at that time.

I used to have a lot of the early permeability charts from Pioneer, North, Ansell, and some of the other suppliers. I'm not sure, but I think there were some organic mercury compounds on them that might at least be thought of as analogous to dimethyl mercury. But every chart has somewhere on it a technical number to call if your chemical is not there or it is a mixture that you need some advice about. And that was what should have been done.

Again, we in the theater shops knew how to do this. My question always is in these cases, how's come youse guys .........?.

Monona

-----Original Message-----
From: Samuella Sigmann <sigmannsb**At_Symbol_Here**appstate.edu>
To: Monona Rossol <actsnyc**At_Symbol_Here**CS.COM>; DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Tue, Mar 22, 2022 11:55 am
Subject: Re: [External] Re: [DCHAS-L] OSHA materials on Karen Wetterhahn's mercury exposure

Here is an excerpt from "The Trembling edge of Science" from the Dartmouth Alumni Magazine

Chemists routinely consult material safety data sheets compiled by chemical manufacturer and suppliers for information about protections against specific chemicals. Three material safety data sheets (MSDS) were available for dimethylmercury. Alfa Aesar, the chemical supplier from whom Wetterhahn bought the dimethylmercury, recommended "rubber gloves." Organometallics, the company that manufactured the dimethylmercury, recommended gloves made of the synthetic rubber neoprene. Sigma Aldrich, the chemical supplier that produced the third MSDS, recommended wearing "chemically impervious gloves." However, "there is no such thing," says the College's health and safety director, Michael Blayney. "No glove is completely impermeable." The rates of permeability vary according to the glove type and the chemical involved. Despite the recommendations on the material safety data sheets, Blayney says, no one had actually tested any kind of protective gloves to see how they stood up to dimethylmercury.

I have not been able to find an archived MSDS, but did locate a NJ Hazardous Fact Sheet from 1989.
Sammye

On 3/22/2022 11:06 AM, Monona Rossol wrote:

I'd be very interested in anything you find on this, James. And when the chemical the glove is made from does not also include the mil thickness, that is pretty useless information. If you doubt this, look at Kimberly Clark's thin mill nitrile charts. Most of those solvents go through in a minute or two.

Monona

-----Original Message-----
From: James Kaufman <jkaufman**At_Symbol_Here**LABSAFETYINSTITUTE.ORG>
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Tue, Mar 22, 2022 10:25 am
Subject: Re: [DCHAS-L] OSHA materials on Karen Wetterhahn's mercury exposure

Can anyone share a copy of the MSDS that was from the actual DMM supplier? ... Jim

PS. The CSB video said that MSDS recommended latex gloves. I have been unable to locate the MSDS. I did get one from Strem Chemicals from that timeframe but it did not say that.

James A. Kaufman, PhD

Founder/President Emeritus

The Laboratory Safety Institute (LSI)

A Nonprofit Educational Organization for Safety in Science, Industry, and Education

192 Worcester Street, Natick, MA 01760-2252

(O) 508-647-1900 (F) 508-647-0062 (C) 508-574-6264 Skype: labsafe; 508-401-7406

jkaufman**At_Symbol_Here**labsafety.org www.labsafety.org Teach, Learn, and Practice Science Safely

On Tue, Mar 22, 2022 at 10:06 AM Ralph Stuart <ralph**At_Symbol_Here**rstuartcih.org> wrote:

>And wondering about Karen's gloves, were they standard dry-box gloves or did she double glove them inside of the glove-box with another type of glove, as we sometimes double glove with our disposable tactile gloves.

I believe that Dr. Wetterhahn was working in a fume hood rather than a glove box on the occasion of her mercury exposure. I assume that she was using the fume hood to control the fire hazard associated with the dimethyl mercury (flashpoint = 5 degrees C), but the fume hood does not add value with regard to dermal toxicity hazards; and latex gloves add minimial protective value as well. OSHA reports that the dexterity value of the latex gloves led to that choice. I believe that the OSHA presentation on this event suggested that Silvershield gloves were the only appropriate choice at that time.

One of the learning points I take from this story is the challenge of working with chemicals that present multiple hazards while balancing chemical and human factors.

- Ralph

Ralph Stuart, CIH, CCHO
ralph**At_Symbol_Here**rstuartcih.org

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Samuella B. Sigmann, MS, NRCC-CHO

Chair, ACS Committee on Chemical Safety

Fellow & 2019 Chair, ACS Division of Chemical Health & Safety

Appalachian State University, Retired

Phone: 336 877 5147

Email: sigmannsb**At_Symbol_Here**retired.appstate.edu

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