From:
Monona Rossol <0000030664c37427-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Subject:
Re: [DCHAS-L] Regulations for Snorkels
Date:
Feb 26, 2019 16:08 UTC
Reply-To:
ACS Division of Chemical Health and Safety
In-Reply-To:
Re: [DCHAS-L] Regulations for Snorkels
The principle is that enclosure of the whole process is always best. For general chemistry work, I think that is the only sensible system.
But there are processes going on in your labs and maintenance departments for which that just won't work: welding, soldering, photo developing, or any process which requires people's eyes to be close to the work to observe.
That's when you need an industrial ventilation engineer (as opposed to HVAC) to use the principles in the ACGIH manual to design to the contaminant, the capture area, and the actual task. It's hard to find these engineers -- really hard. But once you find one, you have gold at the end of your rainbow.
Monona
-----Original Message-----
From: Harry J. Elston <helston**At_Symbol_Here**MIDWESTCHEMSAFETY.COM>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Sent: Tue, Feb 26, 2019 9:51 am
Subject: Re: [DCHAS-L] Regulations for Snorkels
Elston's best practice guidance: Use a laboratory chemical hood. "Snorkels" become highly ineffective in capture after a couple of inches from the opening. You can run the calculation yourself from the ACGIH Vent manual, but generally speaking, unless you're almost right on top of the thing you need to need to exhaust, it won't work well.
I abhor them as effective local exhaust ventilation for general chemistry work.
Harry
Oh Wise Ones -
Are there any flow or testing regulations (ANSI or otherwise) for
lab snorkels. Any best practice guidelines?
Thanks in advance,
Sammye
