Date: Thu, 4 Nov 2010 11:40:13 -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: "Shiel, Dan" <dan.shiel**At_Symbol_Here**PFIZER.COM>
Subject: Re: Power strips in hoods
In-Reply-To: A<1781531791.7380.1288878047688.JavaMail.root**At_Symbol_Here**>
I donÕt understand this citation either. We use power strips in our hoods when necessary, but we require them (per our site Chemical Hygiene Plan) to be mounted on the interior side wall of the hood above the working surface so as to be away from potential spills (especially flammable liquids!) and corrosion.  Most, if not all, of our power strips in hoods are also GFCI equipped as well.


NFPA 45 5.6.2 states that hood interiors are normally considered as unclassified electrically; hereÕs the excerpt:


5.6.2    Laboratory work areas, laboratory units, and chemical fume hood interiors shall be considered as unclassified electrically with respect to Article 500 of NFPA 70  , National Electrical Code.

Exception: Under some conditions of hazard, it could be necessary to classify a laboratory work area, or a part thereof, as a hazardous location, for the purpose of designating the electrical installations. [See 10.5.5   (electric motors) and   (refrigerators).]


And hereÕs another relevant NFPA 45 excerpt:


NFPA 45, Standard on Fire Protection for Laboratories Using Chemicals, 2011 Edition

Annex A Explanatory Material 


Locating services, controls, and electrical fixtures external to the hood minimizes the potential hazards of corrosion and arcing. 







Dan Shiel, MBA, CSP, CHMM

Director, Risk Management Services

Pfizer La Jolla/ GO R&D West

10777 Science Center Drive

San Diego, CA 92121




"If you think education is expensive, try ignorance." 

-Derek Bok




From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**] On Behalf Of Don Abramowitz
Sent: Thursday, November 04, 2010 6:41 AM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: Re: [DCHAS-L] Power strips in hoods


I'm not sure I get the citation.  Most hoods have outlets (only) outside the hood, and all the cord-connected devices therein are temporary wiring, in the sense that they are portable and present typically for the duration of a particular process.   Stirrers and hot plates/heating mantles are not typically explosion proof/hazardous location-rated, so I'm not sure what the issue is with the power strip.

I agree that GFCI protected circuits are a very good idea in this location, and I think it would be better to keep the power strip outside the hood to allow for quick access in an upset condition and to protect it from exposure to chemicals/liquids, but I don't think the presence of a power strip in a hood violates a specific standard.


Donald Abramowitz, CIH
Environmental Health & Safety Officer
Bryn Mawr College
Bryn Mawr, PA




The citation sounds right because power strips are not GFI's, but temporary wiring. The plug-ins inside or immediately outside - not good either because of pinch possibility - and designed for plug-in of equipment in the hood, should be GFI, or GFI at the circuit breaker due to the liquid/chemical/contact hazards.


My $0.02 worth...................................... 

Bill Parks

**Providing sound Industrial Hygiene, Occupational Health and Safety, Environmental Health & IAQ, Environmental Science, and Laboratory support services and solutions for nearly 30 years**

--- On Thu, 11/4/10, Bill Galdenzi  wrote:

	From: Bill Galdenzi 
	Subject: [DCHAS-L] Power strips in hoods
	To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
	Date: Thursday, November 4, 2010, 6:51 AM



	Does anyone have policies or know of requirements for power strips, and similar power supply units, in hoods.   I am referring to not explosion proof rated hoods and areas.    


	I know of a incident that happened years ago that involved a chemical explosion in a hood that injured a chemist.   OSHA investigated and the only "citation" was for use of "temporary" wiring inside a hood.   The OSHA inspector considered the power strip temporary wiring and prohibited them from inside the hood. 


	Please let me know. 



	Bill Galdenzi

	Environmental, Health, and Safety 

	Boehringer-Ingelheim Pharamceuticals 

	(203) 778-7759 




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