From: Zack Mansdorf <mansdorfz**At_Symbol_Here**BELLSOUTH.NET>
Subject: Re: [DCHAS-L] [EXTERNAL] [DCHAS-L] Wearing cloth mask in the lab
Date: Wed, 6 May 2020 15:53:36 -0400
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Message-ID: 006201d623e0$08b7d480$1a277d80$**At_Symbol_Here**
In-Reply-To <38C37009-1E39-43FD-9836-AFAA3FA73C0F**At_Symbol_Here**>

Furthering the discussion, I have been following the absolute anguish and
alarm over the CDC recommendations by the general industrial hygiene and
safety communities. While I won't address the issue of the publics use of
this PPE which is not NIOSH approved (we can argue about the definition
later), it should be clear that there is no single best practice for lab
safety otherwise we all won't have a job-just a "how to" book.

I personally believe (and may be proven wrong) that we have overdone the
precautionary principle. The likelihood of being infected from a fomite in
a laboratory following normal cleaning processes is incredibly small in my
estimation as the infections are from virus that are airborne and enter the
nose. If there is a need for a respirator because of the procedure, one
should be worn and the problem is solved (other than cleaning). If there is
no need for a respirator (e.g., working in a hood), a face shield should be
more than adequate to significantly reduce the travel of any airborne
particles containing COVID19. If you are working alone, then you don't need
any covering.

Ok, you say none of this has been proven or even demonstrated. I say
"fine". Don't open the lab until 2021 when we have all the research and an
effective proven vaccine. One more minor point, if you are under 55-you are
more likely to die visiting Monna by crossing a NYC street than from an
infection from COVID19 (there are exceptions but extremely unlikely). Where
I live (Palm Beach County-Boca Raton), there are no deaths for anyone under
55 and 89.5% of all persons testing positive (over 30,000) have not gone to
the hospital and have recovered on their own.

Bottom line-exercise your best judgement as we normally do with the
potential for hazards in a lab. I would not routinely recommend a bandana
be worn. If you have the N95 or better available and want to be cautious,
then use them. Decon using one of the methods identified as effective (e.g.
hydrogen peroxide spray, ethanol, etc.).

S.Z. Mansdorf, PhD, CIH, CSP, QEP
Consultant in EHS and Sustainability
7184 Via Palomar
Boca Raton, FL 33433

-----Original Message-----
From: ACS Division of Chemical Health and Safety On
Behalf Of Stuart, Ralph
Sent: Wednesday, May 6, 2020 1:43 PM
Subject: Re: [DCHAS-L] [EXTERNAL] [DCHAS-L] Wearing cloth mask in the lab

> >It would be helpful if AIHA or ACS could release a statement on the use
of cloth masks in laboratories.

The problem I see with this relates to most of the issues you mention: the
definition of "laboratories" is so broad that developing a statement beyond
the broad advice that CDC produces is a significant challenge. Even within a
chemistry department, organic labs, analytic labs and teaching labs present
three very different risk scenarios and people are likely to be moving
seamlessly among them. I've had enough experience with trying to develop a
glove usage policy for a diverse lab setting to wonder if we'll get much
further with masks. This is particularly true since, as you point out, the
purpose of cloth masks is unclear, both to safety professionals and the

There is also the down side of cloth masks as with any PPE, to consider:
1. fogging of eyewear, whether prescription or safety 2. developing and
maintaining an awareness of the importance of proper fit 3. interference
with verbal clear communication with labmates 4. identifying appropriate
decontamination and reuse protocols for the masks after use (someone
compared a used mask to a used diaper, without the color indicator to
indicate a contamination problem)

Thanks for helping us to think through this challenge.

- Ralph

Ralph Stuart, CIH, CCHO
Environmental Safety Manager
Keene State College
603 358-2859


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