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Previous by Date: Subject: Re: [DCHAS-L] laboratory located next to cafeteria Date: Thursday, March 2, 2017 at 5:07:56 AM Author: Daniel Kuespert <dankuespert**At_Symbol_Here**ME.COM> |
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These are industrial stacks. ASHRAE, bless it's heart, does have all kinds of lab standards for off the shelf fume hoods and grease hood stuff. But if you want the straight poop, the reference for stack design should be from the ACGIH's Industrial Ventilation: A Manual of Recommended Practice. See section 5.23. Use the 29th Edition now, 2013.
I didn't weigh in before, because we don't know enough to say much. The whole picture of where those two sets of stacks are located with respect to all the building's roof line structures as well as buildings it is near are part of that calculation. I've been on many jobs where we've had to do expensive smoke chamber modeling to determine the height of the stacks. The stuff has to get into moving air space and depending on prevailing winds and the buildings nearby, that can be a problem.
In one of the cases we were building 3 stories and there were 4 and 5 story buildings on either side of us. The stack design had to become an architectural feature to meet the rules.
And while I'm at it, another pet peeve (you knew I had one, right?) is the way ASHRAE's Ventilation for Acceptable Indoor Air Quality (ASHRAE 62) has changed it's references to ACGIH's standards. Back in the 1990s they made it clear in the text itself that their standards are not for ventilation of Class 4 air (air that can cause health damage) and that the ACGIH manual had those standards. That paragraph got smaller and smaller until now it is a footnote in a table in all the standards after 2001. But I can tell you for sure, both air quality in labss and stack height are industrial issues. And stack height and placement will regulated by EPA and your local DEP/Fire Dept/etc. Should it end up in court, it is the ACGIH manual that will be Exhibit 1. Been there.
ASHRAE = the American Society of Heating, Refrigerating, and Air-conditioning Engineers. Do you see any reference to industrial systems in that title? And watch out: Table 6-1 Minimum Ventilation Rates in Breathing Zone in ASHRAE 62 will mislead you. When they list the ventilation rates for laboratories, training shops, photo studios and other industrial purpose areas, their assumption is that only negligible amounts of contaminants escape the ventilation systems. So if you are talking about a conservation lab where solvents are used in the open or a chemical photo developing lab, the ASHRAE standards are NOT applicable. The turn over of air in either a dilution or a displacement ventilation system for those spaces is totally dependent on the ACGIH calculations (Chapter 4 in the manual) for keeping the air contaminants below their TLVs.
Now your are talking about my Bible.
---
This e-mail is from DCHAS-L, the e-mail list of the ACS Division of Chemical Health and Safety.
For more information about the list, contact the Divisional secretary at secretary**At_Symbol_Here**dchas.org
Monona Rossol, M.S., M.F.A., Industrial Hygienist
President: Arts, Crafts & Theater Safety, Inc.
Safety Officer: Local USA829, IATSE
181 Thompson St., #23
New York, NY 10012 212-777-0062
-----Original Message-----
From: Daniel Kuespert <dankuespert**At_Symbol_Here**ME.COM>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Sent: Thu, Mar 2, 2017 6:12 am
Subject: Re: [DCHAS-L] laboratory located next to cafeteria
Even more than the colocation of lab and cafeteria, I'm concerned about the way the discussion morphed from "how can we be safe" to "how can we comply"-as you certainly know, they're not the same. Always an alarm bell for me.
---
This e-mail is from DCHAS-L, the e-mail list of the ACS Division of Chemical Health and Safety.
For more information about the list, contact the Divisional secretary at secretary**At_Symbol_Here**dchas.org
You might try refocusing the conversation a bit. The ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) Handbook has material on stack heights, inlets, and reentrainment that you could probably use for initial support. If you have to fall back on regs, the ASHRAE material is certainly something OSHA would look at in determining that it was a "recognized hazard" and thus a General Duty Clause issue. The relevant material is probably in the volume on "HVAC Applications."
The location of the kitchen exhaust is immaterial as long as the fans stay on and it doesn't become an inlet. A low-down inlet and high stack MIGHT work if there is no factor in the area that could disturb the airflow and cause downwashing. Which could be an issue if the buildings on your site are close together (relative to the length and height of the buildings). If the downwash is strong enough, you can short-circuit the hood outlet to the main building air inlets.
If the lab is next to the cafeteria, you're going to need as few penetrations in the wall as possible and the lab kept under negative pressure; wall construction costs might become an issue as well. (Typical cafeteria walls aren't built to laboratory tightness and so might need to be rebuilt.) If you end up having to put the lab there, might want to restrict what can be used or done in there-one wouldn=E2=80™t want to have the A/C fail, have the lab get positively pressurized, and not be able to shut down whatever reaction they're running. Alternatively, if you can rely on the researchers to follow SOPs, including an air failure alarm with instructions to shut all chemical bottles and quench any vapor-emitting reactions would work.
I personally wouldn't do SF6 tracer work unless you'd already built the stacks, in which case you're already out X tens of thousands for construction in sunk cost and you're trying to see if it can be salvaged. If Michelin has access to fluid-dynamics software like Comsol, somebody with expertise in that could probably run some simulations of various conditions for you much more cheaply.
Regards,
dan kuespert
Fabulous Engineer
On Feb 28, 2017, at 13:46, Melissa Ballard <melissa.ballard**At_Symbol_Here**MICHELIN.COM> wrote:
--- This e-mail is from DCHAS-L, the e-mail list of the ACS Division of Chemical Health and Safety. For more information about the list, contact the Divisional secretary at secretary**At_Symbol_Here**dchas.orgI would appreciate your help again with a lab design issue. My fabulous engineering colleagues want to locate a new lab next to a cafeteria, sharing a wall. I do not like this idea. The cafeteria is a full kitchen cafeteria where it will have its own exhaust system right next to the chemical laboratory. Their solution is to have the kitchen exhaust stacks "short" and the chemical lab exhaust stacks "high" to try & eliminate the occurrence of any chemical exhaust being drawn into the kitchen intake. I have objected to this but they want a "regulation" that says they can't do this. My professional judgment isn't enough.
Any ideas?
Melissa Ballard, MSPH, CIH, CCHO
Industrial Hygienist / Industrial Hygiene Chemist
Michelin North America
1401 Antioch Church Road
IH Lab - Bldg 150 - 1st Floor
Greenville, SC 29605
Internal: 787-1843
Office: (864) 458-1843
Cell: (864) 784-9883
Fax: (864) 458-0070
D3 - Michelin Restricted
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