Based on the range of responses I received to yesterday's inquiry about fume hood flow indicators, it's clear that this is unsettled question (except where regulators have written specific technologies into code in specific jurisdictions). I probably didn't make clear enough that our intent is to improve our fume training by simplifying our message. A campuswide retrofit of 400 hoods is not in the cards. Our current training approach has been in place in various forms for at least 10 years and we aren't seeing any improvement in hood use practices (which is not to say that many UVM people don't use them well). We are seeing some serious problems, particularly in terms of poor hood practices and unnecessary energy use (these poor practices are often inspired by the alarm systems we do have in place). As an article in C&EN recently suggested, I believe that laboratory workers are going to need to address the energy issue relative to hoods fairly soon as concerns over greenhouse gas emissions intensify. One other caveat: I am talking in terms of "generic lab hoods" on our campus. I recognize that there are some chemical processes that require specific protective ventilation and such systems would not be included in the "fancy kimwipe" approach. Anyway, thanks for everyone for their response and I'd be glad to hear more peoples' thoughts. - Ralph From: ACTSNYC**At_Symbol_Here**cs.com Date: February 7, 2008 2:01:30 PM EST (CA) Subject: Re: [DCHAS-L] Fume hood flow indicators In the art and theater departments, I try to get them to buy a Velometer--the Alnor type that doesn't need batteries and can go a long time without calibration. I teach them to use it and then they can really check their own air flow. Monona == From: Dan CrowlDate: February 7, 2008 1:58:36 PM EST (CA) Subject: Re: [DCHAS-L] Fume hood flow indicators Hi Ralph, We use the red ink manometer types - they cost a lost less than the electronic units and can't be disabled and don't send out alarms. Dan Crowl Michigan Tech == From: "Debbie M. Decker" Date: February 7, 2008 2:11:08 PM EST (CA) Subject: Re: [DCHAS-L] Fume hood flow indicators Ralph: It is now a regulatory requirement that all fume hoods (no grandfathering) have a visual/audible alarm and that users are trained on what the alarms mean. We've been installing monitors on our fume hoods, here, for about 10 years so compliance hasn't been too onerous. But it is taking time to get old hoods retrofitted. About 250 to retrofit out of about 1600 hoods. I agree with the requirement myself. Though I have seen a pipette tip jammed into the "mute" button on the alarm to shut it up when the hood is operated incorrectly . Debbie == From: Georjean Adams Date: February 7, 2008 11:13:54 AM EST (CA) To: Ralph Stuart Subject: Re: [DCHAS-L] Fume hood flow indicators I'm interested in your thoughts: I am on the ACS Board Committee for Environmental Improvement and am going to propose at our New Orleans meeting that CEI sponsor a broad collaborative program of compiling and disseminating best practices, identifying technology development needs, educating all members of ACS plus schools and industry, maybe even tracking some metric to show improvement in correct use of fume hoods. I assume DCHAS would be a major contributor to the effort. Do you think it has potential? Does the chemical enterprise need it? Would it generate some energy in the ACS membership? Would people in DCHAS be willing to actually work it? Seems like such a concrete, cross-membership endeavor that could show some real short term benefits to safety and energy reduction and would be more rewarding than some of the high-falutin' policy statements CEI normally works on. Not that I am an expert on hoods. Far from it. (In fact, I'm a policy wonk who's never worked in a lab!) And I'm not positioned to directly manage a big program ( a lone, part-time consultant in chemical management issues who can't travel to meetings all over). Thanks! Georjean -- EHS Strategies, Inc. - enabling organizations to meet their EHS vision www.ehsstrategies.com 651-204-3371 == From: "Greene, Benjamin (WSTF-RF)[JTI]" Date: February 7, 2008 11:55:54 AM EST (CA) Subject: RE: [DCHAS-L] Fume hood flow indicators Hi Ralph - telltale flags on all hoods is a must, and depending on the geometry of the lab the use of hemispherical mirrors to be able to tell if the hoods are working when looking in through a window (if you have them). I agree that the flow alarms may not be reliable and it is sometimes unclear what they are sensing (static pressure, flow, etc.). Ultimately you can end up with either silenced alarms or alarms that don't alarm when they are supposed to, not to mention alarms that go off when they aren't supposed to. So to have a good alarm program you have to have the maintenance to go along with it. Ben == From: "Hadden, Susan [PRDUS]" Date: February 7, 2008 1:03:25 PM EST (CA) To: "Ralph Stuart" Subject: RE: [DCHAS-L] Fume hood flow indicators It's really a behavior issue. Why would they pay attention to a telltale and not an alarm? At least the alarm is annoying enough to attract their attention. I would suggest installing the alarms and training the individuals as to what it means. Then put a sign next to the alarm that explains what it means (ie If the alarm is going off, the hood may not be protecting you). Or consider making it so that they can not turn off the alarm but must have Maintenance respond to reset it. That will really annoy them but will allow Maintenance to evaluate actual hood performance when resetting the alarm. Or, if possible, have a simultaneous alarm in the Maintenance monitoring area that indicates an alarm has gone off. I work at a large pharma company and we have some folks who disable their alarms too. But we do quarterly lab inspections and check for that. We also try to continually educate as to how the hoods work and why a sufficient flow rate is needed to protect them. == From: "Harry J. Elston" Date: February 7, 2008 11:34:02 AM EST (CA) To: Ralph Stuart Subject: Re: [DCHAS-L] Fume hood flow indicators Ralph, I think you're going to run into problems with NFPA 45 and ANSI Z9.5: 6-8.7.1: A flow monitor shall be installed on each new laboratory hood. 6-8.7.2: A flow monitor shall also be installed on existing laboratory hoods whenever any modifications or changes are made that can affect laboratory ventilation or the airflow through existing laboratories. That's from the 1996 version, the only one here I have at the day job. I don't have a copy of ANSI Z9.5 here with me at the day job, but I would wager that the most recent version has something to say about that. One of the hangups is "flow" - not d/p across the hood wall. The only product that I've seen measure actual flow is am in-duct "Flow Cross" that Swiki Anderson uses. Harry Harry J. Elston, Ph.D., CIH Principal Midwest Chemical Safety, LLC www.midwestchemsafety.com Editor, Chemical Health & Safety http://membership.acs.org/c/chas/ == From: "Haugen, Bob" Date: February 7, 2008 2:42:23 PM EST (CA) Subject: RE: [DCHAS-L] Fume hood flow indicators Ralph: I respectfully disagree. Of course, our company makes alarms as well as fume hoods, but "tell tales" are affected by humidity, and are difficult to calibrate. If lab folks are having trouble understanding electric alarms, you might consider a safety seminar (or PowerPoint Video) explaining how to use the hoods and safety alarms. Also, standardizing on a certain model campus-wide might help. Regards, Dr. Bob Haugen KEWAUNEE SCIENTIFIC == From: "Janet Baum" Date: February 7, 2008 11:45:40 AM EST (CA) Subject: RE: [DCHAS-L] Fume hood flow indicators Dear Ralph, As I understand this issue, it is a legal requirement in the "Right To Know" law that chemical fume hoods have electronic flow alarm system installed. Consult the General Counsel for your university before proceeding. Further, it is also a matter of training and education of bench scientists/laboratory workers in the care and use of these devices instead of disabling the alarm system for their immediate convenience and gratification. Your operating and/or engineering groups who maintain building ventilation systems should be engaged with the laboratory manager and EHS staff to investigate incidents of false-alarms, or fluctuations in flows that legitimately set off alarms. Janet Baum, AIA Health, Education + Research Associates, Inc. == From: Jennifer Minogue Date: February 7, 2008 11:02:06 AM EST (CA) Subject: Re: [DCHAS-L] Fume hood flow indicators The Ontario Fire Code requires alarms so we are stuck with them. However, I think most of them work OK. We also have many fume hoods retrofitted with "Ventalerts" which get checked once per year and have a battery change at the same time. These are on old hoods that didn't have alarms on them when installed. I find the stack affect can fool the user into thinking the fume hood is operating when it is not. Pilot lights can also fool you - burned out or, in one case, the light was on but the fire damper had shut due to corrosion so the fan was running but there was no draw. Cheers, Jennifer Jennifer Minogue Biosafety Officer Environmental Health and Safety University of Guelph Guelph, Ontario N1G 2W1 Canada Voice 519-824-4120-x53190 Fax 519-824-0364 == From: "Laurence Doemeny" Date: February 7, 2008 12:26:18 PM EST (CA) Subject: FW: [DCHAS-L] Fume hood flow indicators Hi Ralph, We had bubble gum lights and alarms outside each lab bank that would go off should the airflow fall below a preset level. It was also connected to our Johnson controls facility management system. The audio alarm could be switched off but the gumball lights kept running until maintenance reset them. This system was useful during routine maintenance too, although during those occasions announcements were sent to all building occupants. If you are interested, I can give you the name of the facilities engineer for you to contact. Larry == From: "Peter Reinhardt" Date: February 7, 2008 4:48:47 PM EST (CA) To: "'Ralph Stuart'" Subject: FW: [DCHAS-L] Fume hood flow indicators Ralph, Magnehelic gauges on all hoods! The users need to know what's happening with the latest technology. I wouldn't want to rely on a Kimwipe in court testimony. With all due respect to your great wisdom, I think you are going backwards on your fume hood program. Hoods are the primary means of reducing lab exposures. They need to work properly, the users need to know how to determine that, and EHS needs to verify that. Users need training. There is NO TOXILOGICAL DATA for most chemicals used in labs. Many of these people will spend their lives working in a lab. Small chronic exposures is a huge risk to them. Training, not Kimwipes! Pete == From: "R Alton Simpson (asimpson)" Date: February 7, 2008 2:33:35 PM EST (CA) To: Ralph Stuart Subject: FW: [DCHAS-L] Fume hood flow indicators We have relatively good experience with the digital flow meters. I would not want to go back to a more qualitative system. We inform people about the system during in person training, and we have an on- line tutorial at http://ehs.memphis.edu/HoodTutorial.ppt. Al Alton Simpson, CHMM, NRCC-CHO Director, Environmental Health and Safety The University of Memphis 216 Browning Hall Memphis, TN 38152-3340 (901) 678-4672 fax (901) 678-4673 http://ehs.memphis.edu == From: "Rincon, Katherine" Date: February 7, 2008 11:25:25 AM EST (CA) To: "Ralph Stuart" Subject: RE: [DCHAS-L] Fume hood flow indicators Hello Mr. Stuart: We have the same problem with the electronic flow alarms for our fume hoods as well; and using the Kimwipe doesn't give a flow rate. We use the No. 480 Vaneometer Air Velocity Meter by Dwyer; the user spot checks the hood to verify the flow. We placed them in every fume hood. We start using them for the fume hoods that did not have any type of electronic alarm but then we started having problems with the ones that did due to calibration problems. Also, the Fire Marshals wanted us to provide some kind of visual aid to indicate that the hoods were working. Every lab that has a fume hood gets a meter. One meter is enough to check several hoods in the lab. And of course, it is used only for spot checks by the hood user. It costs around $25.00. Best regards, Kathy Katherine Rincon Chemical Hygiene Manager Environmental Health & Safety University of Texas at El Paso (915) 747-8135 (915) 747-8126 fax == From: "Robin M. Izzo" Date: February 7, 2008 1:51:36 PM EST (CA) Subject: Re: [C2E2-L] Fume hood flow indicators Ralph, We require a magnehelic gauge or a digital flow readout, but without alarms. Our experience is similar to yours - the students will find a way to silence them forever. - Robin Robin M. Izzo Associate Director, EHS Princeton University 609-258-6259 (office) The purpose of life is to live it, to taste experience to the utmost, to reach out eagerly and without fear for newer and richer experience. -Eleanor Roosevelt == From: Stanley K Lengerich Date: February 7, 2008 4:58:31 PM EST (CA) Subject: Re: [DCHAS-L] Fume hood flow indicators Hi Ralph, I read a lot of DCHAS messages, but this is the first one I've felt strongly compelled to respond to. I would highly discourage you from taking the route you have proposed regarding face velocity monitors. My concern would be that the qualitative telltale would be understood even less by the user, and it wouldn't have the necessary sensitivity to measure when flows have dropped out of a safe range. Also, I would think that it probably doesn't meet the spirit and intent of the OSHA (Federal) Lab Standard requirements for monitoring fume hoods. It is true that too much information can confuse the fume hood user. We previously had a lot of monitors displaying the flow in feet per minute, and that created too much confusion for the user. For that reason we have been transitioning to monitors that use a safe/unsafe (green light/red light) indication, and the red light is accompanied by an audible alarm. The audible alarm is silenceable, but if the alarm condition is not satisfied within 10 minutes, it automatically reactivates (the red light always stays on during an alarm condition). We find that this strikes a reasonable balance of warning vs. nuisance so that the users don't try to defeat the audible alarm. The simpler, universally-recognized, green/red warning system is easy to understand and easy to train on, and it still provides the necessary measurement sensitivity. Best Regards, Stan Lengerich, CIH Engineering Consultant Eli Lilly and Company Indianapolis, IN 46285 Ralph Stuart, CIH Environmental Safety Manager University of Vermont Environmental Safety Facility 667 Spear St. Burlington, VT 05405 rstuart**At_Symbol_Here**uvm.edu fax: (802)656-5407
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