Jack,
In my opinion, a horizontal sliding sash is not safer. I have observed the following when individuals are working in the hood with this type of sash.
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The sash panels are moved all the way over to one side to work unprotected.
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There is a tendency for the student/worker to cross the sash plain to observe the reaction placing their head in the hood.
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Some users move one panel in front of their body for protection while leaving sides open to allow for the hands and arms to work in the hood. This creates large openings which would not sufficiently protect the
user from shrapnel if an adverse reaction occurs.
Just my two cents.
Martin W. Bell, M.S. CIH CSP
Executive Director
Environmental Health and Radiation Safety
Drexel University
400 North 31st Street
Philadelphia, PA 19104
Tel: 215.895.5892 | Fax: 215.895.5926
Mobile: 215-778-4278
drexel.edu/facilities/healthsafety
From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU> on behalf of Jack Reidy <0000233ca1fd2102-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Date: Friday, April 3, 2026 at 10:43 AM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Subject: [DCHAS-L] Horizontal vs. vertical sashes
Hi all,
A new PI joining our Chemistry Department is sharing a very strong preference for vertically-split fume hood sashes (i.e., ones that open side to side), saying that they’re safer. Is anyone aware of any studies on this, or have
any other insights? Thanks!
Sincerely,
Jack Reidy (he/him)
Research Safety Specialist & Chemical Hygiene Officer
Environmental Health & Safety
Stanford University
484 Oak Road, Stanford, CA, 94305
Tel: (650) 497-7614
I acknowledge that the land on which I live and work is the ancestral and unceded land of the
Muwekma
Ohlone Tribe. As an uninvited guest on these lands, I am a beneficiary of the ongoing displacement of the Ohlone people. I pay my respects to the Native peoples, past and present.
