DCHAS-L Discussion List Archive
Date: Thu, 30 Sep 2010 07:55:11 -0400
Reply-To: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Kim Auletta <kauletta**At_Symbol_Here**NOTES.CC.SUNYSB.EDU>
Subject: Re: Need fume hood/fire alarm help
In-Reply-To: <20100929121615.834b022cd1aa24b0911e6cb2fed6c2a3.f9114e84f8.wbe**At_Symbol_Here**email06.secureserver.net>
Thanks, everyone for your suggestions. I will pass them all on to the
consultant & building staff.
Just to restate - the imbalance & inability to open the doors is not
during our normal operations, but when the fire alarm is activated & the
supply is shut down. We do have sufficient make up air in the building for
our day-to-day work.
Kim Auletta
Lab Safety Specialist
EH&S Z=6200
Stony Brook University
kauletta**At_Symbol_Here**notes.cc.sunysb.edu
631-632-3032
EH&S Web site: http://www.stonybrook.edu/ehs/lab/
Remember to wash your hands!
From:
scrooks**At_Symbol_Here**PPEPPRO.COM
To:
DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Date:
09/29/2010 08:39 PM
Subject:
Re: [DCHAS-L] Need fume hood/fire alarm help
Sent by:
DCHAS-L Discussion List
Kim,
Life safety has to trump the standards you mention. I can speak directly
to ANSI Z9.5 and that upcoming revision (which was written with an
expectation that NFPA 45 is also addressing your situation in their next
revision.)
Z9.5 may not provide absolute clarity nor the answer that you're looking
for but it does attempt to fix the unintended earlier recipe for egress
issues. And although the update/publication is being held up while we
address a seprate public objection, the section addressing your question
will read as follows:
Within Section 5.2.3 Laboratory Ventilation - Emergency Modes
Left-hand column "shall" text
FIRE – Any manual or automatic means of detecting fire (such as a pull
station or smoke detector) in a laboratory room shall also activate an
appropriate fire emergency mode of operation for the room and/or building
ventilation system.
The selected fire emergency mode shall operate all supply and exhaust
equipment in the room in a manner that promotes egress, retards the spread
of fire and smoke, and complies with applicable fire safety codes and
standards.
Right-hand column "explanatory or should" text
The intent of the fire emergency ventilation mode is to promote safe
egress. This means apply negative pressurization in the room of fire
origin in order to retard the spread of smoke and toxic fire gases to
other parts of the facility but do not pressurize to the extent that the
force needed to open the door is excessive. (Also refer to the current
versions of NFPA 92A and NFPA 45.)
The common practice of cutting off supply air to a fire zone does not
apply to some laboratories. The combination of a high exhaust rate and no
supply can depressurize a room so far that some occupants would be unable
to open the doors. The initial design of the laboratory ventilation
system must include analysis of flow rates, pressure levels and forces on
the door to ensure that egress is possible.
Regards,
Steve Crooks, MS, CIH, CSP
Chair, AIHA/ANSI Z9.5-22010
-------- Original Message --------
Subject: [DCHAS-L] Need fume hood/fire alarm help
From: Kim Auletta
Date: Wed, September 29, 2010 1:42 pm
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
We have recently renovated 2 floors of our 7 story Chemistry building.
This job included adding MANY more fume hoods than were already in the
building. The NFPA/ANSI/common sense code requires that the fume hoods
stay & the supply air/HVAC system shuts off when the fire alarm is
activated. Of course, this now makes the building so negative that they
can't easily open the doors at the bottom of the stairwell/emergency exit
and all the doors quickly slam shut. The consultant is at a loss of what
to do to fix this.
How have your large buildings with numerous hoods dealt with this problem?
Have you found a door mechanism that allows a person to overcome the
severe negative imbalance and safely exit? Any advice or examples are
greatly appreciated.
NFPA 45, Sect. 8.10.4 Fire detection and alarm systems shall not be
interlocked to automatically shut down chemical fume hood exhaust fans.
8.10.5 Proper door operation for egress shall be maintained when the
supply system shuts down and the lab exhaust system operates, creating a
pressure differential.
Thanks!
Kim Auletta
Lab Safety Specialist
EH&S Z=6200
Stony Brook University
kauletta**At_Symbol_Here**notes.cc.sunysb.edu
631-632-3032
EH&S Web site: http://www.stonybrook.edu/ehs/lab/
Remember to wash your hands!
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