From:
Andy Glode <00001c047c05fd7f-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Subject:
Re: [DCHAS-L] Horizontal vs. vertical sashes
Date:
Apr 3, 2026 18:02 UTC
Reply-To:
ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Message-ID:
<CH0P223MB007469DE52C4F4A9A454D51F8A5EA**At_Symbol_Here**CH0P223MB0074.NAMP223.PROD.OUTLOOK.COM>
In-Reply-To:
<BYAPR02MB56867E5078CF184EE002E7498C51A**At_Symbol_Here**BYAPR02MB5686.namprd02.prod.outlook.com>
Combination sashes like you describe aren't safer or less safe in my opinion. They can be more convenient for some users, but there are a few things you need to consider:
-
They can be misused just like horizontal sashes. Commonly users stand in front of them like at an open window, with their breathing zone very close to the open hood. We train users to position the panel in front
of them.
-
Width of the panel may impede two handed operations, especially when considering the point above.
-
Hoods with horizontal panels require more air to maintain minimum flow rates because they have a larger open area than a horizontal sash due to the gaps between the panels. This could be a limiting factor if you
cannot increase CFM to the hoods. Our 6 foot hoods with combi sashes require about 50 cfm more than identical hoods with std horizontal sashes.
Good luck,
Andy
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>
Sent: Thursday, April 2, 2026 5:22 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Subject: [DCHAS-L] Horizontal vs. vertical sashes
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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.
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