| About This Archive | | DCHAS-L 2015 Index | | DCHAS-L Yearly Index | |
Check out Safety Emporium for your N95, N99, and face shield needs.
|
Previous by Date: Subject: Re: [DCHAS-L] Quick question for the group Date: Wed, 1 Jul 2015 17:43:28 -0400 Author: Steven Kirincich |
Next by Date: Subject: Re: [DCHAS-L] Quick question for the group Date: Thu, 2 Jul 2015 10:11:32 +0000 Author: Ellen M. Sweet |
Dear All,
We are looking for a design requirement for number of fume hood per researcher in chemistry labs. Is sharing of hoods a good idea? In safety point of view, we should provide adequate space for researchers to work but the energy cost will increase based on the number of hoods in lab. Please share if you have or aware of some requirements or good practices on the allocation of hood space in Chemistry labs.
Thanks in advance
Syam Kumar Prabhakaran (Mr) :: Associate Director, Dean's Office, Faculty of Science :: National University of Singapore
-----Original Message-----
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of DCHAS-L automatic digest system
Sent: Wednesday, July 01, 2015 12:01 PM
To: DCHAS-L**At_Symbol_Here**listserv.med.cornell.edu
Subject: DCHAS-L Digest - 29 Jun 2015 to 30 Jun 2015 (#2015-131)
There are 10 messages totaling 2242 lines in this issue.
Topics of the day:
1. SafetyZone New post: Improving laboratory explosion protection
2. FW: [DCHAS-L] Vented flammables cabinets
3. Vented flammables cabinets
4. Fume hood face velocities (7)
----------------------------------------------------------------------
Date: Tue, 30 Jun 2015 07:37:25 -0400 > Date: Tue, 30 Jun 2015 14:23:18 +0000 I come from the world of process analyzers in the chemical and petrochemical industries where there is frequent reference to the use of flame arrestors (between the analysis equipment and also at the point of discharge post analysis). However as a few correspondents have pointed out flame arrestors seldom add reliability as they are prone to fouling and corrosion. In the best of circumstances they need be sized for the ignition characteristics of the ignitable vapour to be present - and I would respectfully suggest that such information is unlikely to be known or anticipated in the case of storage cabinets. Also flame arrestors are designed not only to prevent propagation of flame through the barrier but also to contain the much higher explosion pressures that can arise from a supersonic blast wave travelling ahead of the flame front (pressure piling) which leads to a supercharging of the explosive gas air mixture and much higher detonation pressures. Consequently flame arre! All to say if a ventilation system is to be used, presumably it is to mitigate the toxic risk, it would require dilution of vapours to a concentration far below that which could be flammable (typically by a factor of >100:1). If such were the case - it would be better to have a monitor on the ventilation flow rate. Chief Scientist Novatech From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Peter Zavon If there is not ducted ventilation through the cabinet, the bungs (both of them), should remain in place. This will likely improve the temperature barrier properties of the unducted cabinet. Unless, of course, the authority having jurisdiction requires otherwise. Then you want those flame arrestors to remain in good condition. If an existing cabinet is exhausted from the high bung rather than the low bung and you can accomplish it without undue difficulty or expense, I would correct the error. PZAVON**At_Symbol_Here**Rochester.rr.com Dear Listers, Thanks in advance and pardon the cross-posting. NFPA 30 states that IF flammable cabinets are ducted to the ventilation system that the supply be provided at the top and the exhaust be connected to the bottom. Presumably, this creates a downward directed cross draft that ensures removal of vapors with high vapor density from the bottom of the cabinet. I have two questions: 1) if there is not a ducted supply does that supply bung stay open or closed? 2) if an existing cabinet is vented with the exhaust from the top should it be changed to vent from the bottom? Many thanks, Chris Christopher E. Kohler, MS, LPG, CCHO Environmental Health and Safety ------------------------------ Date: Tue, 30 Jun 2015 16:06:20 +0000 Several years ago, the campus Fire Marshal and I worked on some guidance for how to properly vent a flammable liquid storage cabinet. Here's the link to the pdf: http://ehs.ucdavis.edu/ps/fp/fn/biefs/ventingFlammableStorageCabinets.pdf/view In that document, if cabinets are not vented, the openings need to be sealed with the bungs supplied. Hope this helps, Debbie M. Decker, CCHO, ACS Fellow Birkett's hypothesis: "Any chemical reaction that proceeds smoothly under normal conditions, can proceed violently in the presence of an idiot." From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Peter Zavon If there is not ducted ventilation through the cabinet, the bungs (both of them), should remain in place. This will likely improve the temperature barrier properties of the unducted cabinet. Unless, of course, the authority having jurisdiction requires otherwise. Then you want those flame arrestors to remain in good condition. If an existing cabinet is exhausted from the high bung rather than the low bung and you can accomplish it without undue difficulty or expense, I would correct the error. PZAVON**At_Symbol_Here**Rochester.rr.com Dear Listers, Thanks in advance and pardon the cross-posting. NFPA 30 states that IF flammable cabinets are ducted to the ventilation system that the supply be provided at the top and the exhaust be connected to the bottom. Presumably, this creates a downward directed cross draft that ensures removal of vapors with high vapor density from the bottom of the cabinet. I have two questions: 1) if there is not a ducted supply does that supply bung stay open or closed? 2) if an existing cabinet is vented with the exhaust from the top should it be changed to vent from the bottom? Many thanks, Chris Christopher E. Kohler, MS, LPG, CCHO Environmental Health and Safety ------------------------------ Date: Tue, 30 Jun 2015 08:54:51 -0700 Hello, Upon performing lab inspections I have noticed hoods that seem, in my opinion, to have excessively high face velocities when the hood sash is in an appropriate position for performance of tasks. These velocities exceed (909)6074217 ------------------------------ Date: Tue, 30 Jun 2015 16:27:56 +0000 Hi Penny! In most cases, the BIG issue is how much energy it costs to exhaust all this conditioned air. (~ $10 to $15 per CFM per year in most localities) The older, square side post hoods with no airfoil are the most likely to produce nasty turbulence as well. Please call me if questions. Very Truly Yours, Dr. Bob Haugen Phone 910 332 4878 From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Penny Manisco -- (909)6074217 Spam<https://antispam.roaringpenguin.com/canit/b.php?iOKEf9Uz&m=4c08c8eb9e33&t 150630&c=s> ------------------------------ Date: Tue, 30 Jun 2015 16:35:34 +0000 Penny , Check the ACGIH Vent Guide for a numbered plate (Drawing) for laboratory hoods. I believe somewhere in th range of 70-100 fpm is the recommendation. As you know the hood sash should be pulled down quite far so as to protect the chemist, usually within a few inches. Our R&D labs pulled the sash down and placed an arrow on the side to indicate where 100fpm was measured. If you have some sort of mixing where you have a very volatile solvent solution and do not want the solvent to evaporate, I have seen as low as 25fpm for this procedure. Hope this helps, Mike Michael A. Buczynski T: +1-973.404.2484 Please think before you print. -- (909)6074217 NOTICE P Please Consider the Environment before printing this Email This email was sent from within RB plc the trading name of Reckitt Benckiser Group plc group of companies (http://www.reccol.com<http://http://www.reccol.com>)This email (and any attachments or hyperlinks within it) may contain information that is confidential, legally privileged or otherwise protected from disclosure. If you are not the intended recipient of this email, you are not entitled to use, disclose, distribute, copy, print, disseminate or rely on this email in any way. If you have received this email in error, please notify the sender immediately by telephone or email and destroy it, and all copies of it. We have taken steps to ensure that this email (and any attachments) are free from computer viruses and the like. However, it is the recipient's responsibility to ensure that it is actually virus free. Any emails that you send to us may be monitored for the purposes of ascertaining whether the communication complies with the law and our policies. ------------------------------ Date: Tue, 30 Jun 2015 16:45:28 +0000 > These velocities exceed 200 f/m in some cases. I found many of our hoods were over 140 fpm; the good news is that the labor costs associated with getting them recommissioned to the design velocity (80 fpm) is easily paid for by the energy savings previously mentioned (and then some). - Ralph Ralph Stuart, CIH, CCHO ralph.stuart**At_Symbol_Here**keene.edu ------------------------------ Date: Tue, 30 Jun 2015 13:01:24 -0400 In addition high velocities can create reverse air flow as the air passing your body creates turbulence that can pull contaminates from the hood. 100 FPM has been the most widely accepted target face velocity but within the past several years hoods have been designed to operate safely at lower speeds. ANSI recognizes velocities as low as 60FPM in some instances. Your 200 FPM is high but may or may not perform for your conditions. You will need to do an ASHRAE 110 test to determine your hood performance. Kurt Rindoks Sent from my iPhone On Jun 30, 2015, at 12:29 PM, Dr Bob Hi Penny! In most cases, the BIG issue is how much energy it costs to exhaust all this conditioned air. (~ $10 to $15 per CFM per year in most localities) The older, square side post hoods with no airfoil are the most likely to produce nasty turbulence as well. Please call me if questions. Very Truly Yours, Dr. Bob Haugen Phone 910 332 4878 From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Penny Manisco -- (909)6074217 Spam<https://antispam.roaringpenguin.com/canit/b.php?iOKEf9Uz&m=4c08c8eb9e33&t 150630&c=s> The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer, multimedia hand held device or phone service. Thank you. ------------------------------ Date: Tue, 30 Jun 2015 17:58:22 +0000 As another poster mentioned, the ASHRAE 110 test is the most reliable way to determine if the hood is containing properly, but before you spend all that money a simple test with a smoke pencil may be enough to demonstrate there is a problem with turbulace-induced leakage and that you need to lower the velocity. If I were to do the ASHRAE test, I would wait and do it after the modifications to make sure I was presenting the client with a reliable hood. W. Wayne Wood | Environmental Health and Safety | McGill University | 3610 rue McTavish Street, 4th floor | Montreal, Quebec, Canada, H3A 1Y2 | Tel: (514) 398-2391 (909)6074217 NOTICE P Please Consider the Environment before printing this Email This email was sent from within RB plc the trading name of Reckitt Benckiser Group plc group of companies (http://www.reccol.com<http://http:/www.reccol.com>)This email (and any attachments or hyperlinks within it) may contain information that is confidential, legally privileged or otherwise protected from disclosure. If you are not the intended recipient of this email, you are not entitled to use, disclose, distribute, copy, print, disseminate or rely on this email in any way. If you have received this email in error, please notify the sender immediately by telephone or email and destroy it, and all copies of it. We have taken steps to ensure that this email (and any attachments) are free from computer viruses and the like. However, it is the recipient's responsibility to ensure that it is actually virus free. Any emails that you send to us may be monitored for the purposes of ascertaining whether the communication complies with the law and our policies. ------------------------------ Date: Tue, 30 Jun 2015 14:34:37 -0700 Hello all, Thanks so much for the input. I'll try the smoke stick method first. Best, Penny On Tue, Jun 30, 2015 at 10:58 AM, Wayne Wood > As another poster mentioned, the ASHRAE 110 test is the most reliable -- (909)6074217 ------------------------------ End of DCHAS-L Digest - 29 Jun 2015 to 30 Jun 2015 (#2015-131) ________________________________ Important: This email is confidential and may be privileged. If you are not the intended recipient, please delete it and notify us immediately; you should not copy or use it for any purpose, nor disclose its contents to any other person. Thank you.
Previous post | Top of Page | Next post
From: "Secretary, ACS Division of Chemical Health and Safety"
Subject: SafetyZone New post: Improving laboratory explosion protection
> New post on The Safety Zone
>
> <http://cenblog.org/the-safety-zone/?author=33>
> Improving laboratory explosion protection
> <http://cenblog.org/the-safety-zone/2015/06/improving-laboratory-explo
> sion-protection/>by Jyllian Kemsley
> <http://cenblog.org/the-safety-zone/?author=33>
> A guest post by Ralph Stuart, secretary of the ACS Division of Chemical Health & Safety (DCHAS) <http://dchas.org/>.
>
> A member of the DCHAS e-mail list recently pointed out to me a story in the Milwaukee Sentinel‰??s archives about a laboratory explosion in 1957 <https://news.google.com/newspapers?nid=1368&dat=19571026&id=mL4VAAAAIBAJ&sjid=_w8EAAAAIBAJ&pg=1819,2498434&hl=en>. The story reported:
>
> Waukesha, Oct. 25 (AP) A Carroll College senior was reported in good condition Friday despite suffering injuries that led to the loss of his left eye after fluid, said to have been rocket fuel, blew up in his face. ... The exploding test tube sent slivers of glass into [the student‰??s] face. One of the pieces pierced his left eye. Afterwards, several college sources said the fluid was rocket fuel, but no one in authority would comment on the reports. ...
>
> Dr. Robert Steele, college president, and Arthur A. Sunier, chemistry professor, both said [the student's] experiment was ‰??entirely unauthorized.‰??
>
> ‰??It was in no way connected with his class work,‰?? said Steele.
>
> The reason the DCHAS reader pointed out this story was that it is has eerie parallels to the 2010 Texas Tech University explosion that triggered the U.S. Chemical Safety & Hazard Investigation Board review of academic laboratory safety <http://www.csb.gov/csb-releases-new-video-on-laboratory-safety-at-academic-institutions/>, 50 years after the Carroll College incident. In both cases, the work with energetic materials was outside the scope of what faculty expected to be conducted in their labs and didn‰??t include appropriate protective equipment for the work being conducted.
>
> Sometimes, this repetition of historic accidents can discourage laboratory safety advocates by suggesting that we are fighting a labor of Sisyphus <https://en.wikipedia.org/wiki/Sisyphus>. One hopeful sign for people engaged in this work is a paper in the latest issue of the Journal of Chemical Health and Safety. The paper, "Protective equipment for small-scale laboratory explosive hazards. Part 2. Shielding materials, eye and face protection <http://www.sciencedirect.com/science/article/pii/S1871553214001285>" presents basic research in understanding the precautions that should be implemented when the risk of a laboratory explosion is prudent to prepare for (2015, DOI: 10.1016/j.jchas.2014.11.004).
>
>
>
> <http://cenblog.org/the-safety-zone/files/2015/06/aluminum-bath-jchas-
> j.jchas_.2014.11.004.jpg> Explosion damage to an aluminum bath.
> Credit: J. Chem. Health Saf.
>
> The paper notes that:
>
> There is a significant quantity of published information on the hazard presented by bare and metal-encased charges, and the level of shielding required to protect against this threat. Unfortunately, the corresponding data for charges encased in glass or ceramic materials, such as those found in standard laboratory apparatus, are more limited.
>
> The authors provide pictures and videos of the results of lab scale explosions and their impact on safety glasses, face shields and safety screens. The authors also provide guidance for selecting among these alternatives for working with various quantities of explosive materials. As evidenced by the articles noted above, this information fills a long standing need for the laboratory safety community. For this reason, I appreciate the work conducted by the authors and their willingness to share their work.
>
> Jyllian Kemsley <http://cenblog.org/the-safety-zone/?author=33> | June
> 30, 2015 at 7:30 am | Categories: Featured
> <http://cenblog.org/the-safety-zone/?taxonomy=category&term=featured>,
> Safety resources
> <http://cenblog.org/the-safety-zone/?taxonomy=category&term=safety-res
> ources> | URL: http://wp.me/pRCdG-pmQ <http://wp.me/pRCdG-pmQ>
------------------------------
From: "Osprey, James"
Subject: FW: [DCHAS-L] Vented flammables cabinets
I followed this discussion with some interest - not least the reference to flame arrestors. I assume the reference is to storage cabinets in NFPA 30 (the term flammable cabinets is not used in NFPA 30). NFPA does not require such cabinets to be vented (9.5.4). but if they are to be vented (9.5.4.2) to be vented directly to a safe location outdoors or to a treatment device to mitigate the formation of VOC's or ignitable vapours to the satisfaction of the AHJ (I paraphrase). Annex A makes it clear why (A 9.5.4) venting is not recommended for fire protection but that it may be required for other reasons (health and safety). In such cases the ventilation should not affect the fire performance. If vented, it recommends venting from the bottom with makeup air supplied at the top (mechanically assisted in accordance with NFPA 91) and the vent should not be combined with other ducts or vents from other storage cabinets. Any vent should be to a safe location free of source of ignitio!
n, consequently there should be no reason for flame arrestors (NFPA 30 does not refer to flame arrestors).
stors are designed for the line size to which they are to be fitted and increase dramatically in both volume and weight with duct diameter - I respectfully suggest that ventilation ducts are unlikely to match the pressure rating requirements of the arrestor.
James Osprey P. Eng. C. Phys
Tel: (514) 339-5374 ext. 208
Cell:(514) 378-9076
Sent: June-29-15 9:48 PM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: Re: [DCHAS-L] Vented flammables cabinets
Peter Zavon, CIH
Penfield, NY
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Kohler, Christopher E
Sent: Monday, June 29, 2015 9:50 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Vented flammables cabinets
Laboratory Safety Manager, EHS
Laboratory Safety Instructor, ACS
Adjunct Faculty, SPEA
1514 E Third Street
Bloomington, IN 47405
(812) 855-5454
cekohler**At_Symbol_Here**iu.edu
Confidentiality Warning:
This message and any attachments are intended only for the use of the intended recipient(s), are confidential, and may contain privileged information. If you are not the intended recipient, you are hereby notified that any review, retransmission, conversion to hard copy, copying, circulation or other use of this message and any attachments is strictly prohibited. If you are not the intended recipient, please notify the sender immediately by return e-mail, and delete this message and any attachments from your system. Thank you.
Information confidentielle:
Le pr?sent message, ainsi que tout fichier qui pourrait y ?tre joint, sont envoy?s ? l'intention exclusive de son ou de ses destinataires; ils sont de nature confidentielle et peuvent constituer une information privil?gi?e. Nous avertissons toute personne autre que le destinataire pr?vu que tout examen, r?acheminement, impression, copie, distribution ou autre utilisation de ce message et de tout fichier qui y est joint est strictement interdit. Si vous n'?tes pas le destinataire pr?vu, veuillez en aviser imm?diatement l'exp?diteur par retour de courriel et supprimer ce message et tout document joint de votre syst?me. Merci.
From: "Debbie M. Decker"
Subject: Re: Vented flammables cabinets
Debbie
Chair, Division of Chemical Health and Safety University of California, Davis
(530)754-7964
(530)304-6728
dmdecker**At_Symbol_Here**ucdavis.edu
Sent: Monday, June 29, 2015 6:48 PM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: Re: [DCHAS-L] Vented flammables cabinets
Peter Zavon, CIH
Penfield, NY
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Kohler, Christopher E
Sent: Monday, June 29, 2015 9:50 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Vented flammables cabinets
Laboratory Safety Manager, EHS
Laboratory Safety Instructor, ACS
Adjunct Faculty, SPEA
1514 E Third Street
Bloomington, IN 47405
(812) 855-5454
cekohler**At_Symbol_Here**iu.edu
From: Penny Manisco
Subject: Fume hood face velocities
200 f/m in some cases. I am concerned that this velocity causes unsafe air turbulence. Since OSHA sets no upper face velocity the hoods pass inspection. Any thoughts or citations would be appreciated.
--
Penny Manisco,
Chemical Hygiene Officer
Harvey Mudd College
From: Dr Bob
Subject: Re: Fume hood face velocities
Director of Product and Technology Development Flow Sciences Inc.
2025 Mercantile Drive
Leland, NC 28451
Sent: Tuesday, June 30, 2015 11:55 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Fume hood face velocities
Hello,
Upon performing lab inspections I have noticed hoods that seem, in my opinion, to have excessively high face velocities when the hood sash is in an appropriate position for performance of tasks. These velocities exceed 200 f/m in some cases. I am concerned that this velocity causes unsafe air turbulence. Since OSHA sets no upper face velocity the hoods pass inspection. Any thoughts or citations would be appreciated.
Penny Manisco,
Chemical Hygiene Officer
Harvey Mudd College
________________________________
Phish/Fraud<https://antispam.roaringpenguin.com/canit/b.php?iOKEf9Uz&m=4c08c8eb9e33&t 150630&c=p>
Not spam<https://antispam.roaringpenguin.com/canit/b.php?iOKEf9Uz&m=4c08c8eb9e33&t 150630&c=n>
Forget previous vote<https://antispam.roaringpenguin.com/canit/b.php?iOKEf9Uz&m=4c08c8eb9e33&t 150630&c=f>
From: "Buczynski, Michael"
Subject: Re: Fume hood face velocities
Director Regulatory Compliance
North America
RB (Reckitt Benckiser)
399 Interpace Parkway
Parsippany, NJ USA 07054-0225
M: +1-973.570.9457
michael.buczynski**At_Symbol_Here**rb.com
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Penny Manisco
Sent: Tuesday, June 30, 2015 11:55 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Fume hood face velocities
Hello,
Upon performing lab inspections I have noticed hoods that seem, in my opinion, to have excessively high face velocities when the hood sash is in an appropriate position for performance of tasks. These velocities exceed 200 f/m in some cases. I am concerned that this velocity causes unsafe air turbulence. Since OSHA sets no upper face velocity the hoods pass inspection. Any thoughts or citations would be appreciated.
Penny Manisco,
Chemical Hygiene Officer
Harvey Mudd College
From: "Stuart, Ralph"
Subject: Re: Fume hood face velocities
Chemical Hygiene Officer
Keene State College
From: "Rindoks, Kurt"
Subject: Re: Fume hood face velocities
VP Engineering and Product Development
Kewaunee Scientific
Director of Product and Technology Development Flow Sciences Inc.
2025 Mercantile Drive
Leland, NC 28451
Sent: Tuesday, June 30, 2015 11:55 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Fume hood face velocities
Hello,
Upon performing lab inspections I have noticed hoods that seem, in my opinion, to have excessively high face velocities when the hood sash is in an appropriate position for performance of tasks. These velocities exceed 200 f/m in some cases. I am concerned that this velocity causes unsafe air turbulence. Since OSHA sets no upper face velocity the hoods pass inspection. Any thoughts or citations would be appreciated.
Penny Manisco,
Chemical Hygiene Officer
Harvey Mudd College
________________________________
Phish/Fraud<https://antispam.roaringpenguin.com/canit/b.php?iOKEf9Uz&m=4c08c8eb9e33&t 150630&c=p>
Not spam<https://antispam.roaringpenguin.com/canit/b.php?iOKEf9Uz&m=4c08c8eb9e33&t 150630&c=n>
Forget previous vote<https://antispam.roaringpenguin.com/canit/b.php?iOKEf9Uz&m=4c08c8eb9e33&t 150630&c=f>
From: Wayne Wood
Subject: Re: Fume hood face velocities
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu] On Behalf Of Penny Manisco
Sent: Tuesday, June 30, 2015 11:55 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Fume hood face velocities
Hello,
Upon performing lab inspections I have noticed hoods that seem, in my opinion, to have excessively high face velocities when the hood sash is in an appropriate position for performance of tasks. These velocities exceed 200 f/m in some cases. I am concerned that this velocity causes unsafe air turbulence. Since OSHA sets no upper face velocity the hoods pass inspection. Any thoughts or citations would be appreciated.
--
Penny Manisco,
Chemical Hygiene Officer
Harvey Mudd College
From: Penny Manisco
Subject: Re: Fume hood face velocities
> way to determine if the hood is containing properly, but before you
> spend all that money a simple test with a smoke pencil may be enough
> to demonstrate there is a problem with turbulace-induced leakage and
> that you need to lower the velocity. If I were to do the ASHRAE test,
> I would wait and do it after the modifications to make sure I was
> presenting the client with a reliable hood.
>
>
>
> W.
>
>
>
> Wayne Wood | Environmental Health and Safety | *McGill University* |
> 3610 rue McTavish Street, 4th floor | Montreal, Quebec, Canada, H3A
> 1Y2 | Tel: (514)
> 398-2391
>
>
>
>
>
> *From:* DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu
>
> *Sent:* Tuesday, June 30, 2015 11:55 AM
> *To:* DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
> *Subject:* [DCHAS-L] Fume hood face velocities
>
>
>
>
> Hello,
>
> Upon performing lab inspections I have noticed hoods that seem, in my
> opinion, to have excessively high face velocities when the hood sash
> is in an appropriate position for performance of tasks. These
> velocities exceed
> 200 f/m in some cases. I am concerned that this velocity causes unsafe
> air turbulence. Since OSHA sets no upper face velocity the hoods pass
> inspection. Any thoughts or citations would be appreciated.
>
> --
>
> Penny Manisco,
> Chemical Hygiene Officer
> Harvey Mudd College
>
> (909)6074217
>
> NOTICE
>
>
>
> P Please Consider the Environment before printing this Email
>
>
>
> This email was sent from within RB plc the trading name of Reckitt
> Benckiser Group plc group of companies (http://www.reccol.com
> <http://http:/www.reccol.com>)This email (and any attachments or
> hyperlinks within it) may contain information that is confidential,
> legally privileged or otherwise protected from disclosure. If you are
> not the intended recipient of this email, you are not entitled to use,
> disclose, distribute, copy, print, disseminate or rely on this email
> in any way. If you have received this email in error, please notify
> the sender immediately by telephone or email and destroy it, and all copies of it.
>
> We have taken steps to ensure that this email (and any attachments)
> are free from computer viruses and the like. However, it is the
> recipient's responsibility to ensure that it is actually virus free.
> Any emails that you send to us may be monitored for the purposes of
> ascertaining whether the communication complies with the law and our policies.
>
Penny Manisco,
Chemical Hygiene Officer
Harvey Mudd College
**************************************************************