From: Dr Bob <drbob**At_Symbol_Here**FLOWSCIENCES.COM>
Subject: Re: [DCHAS-L] Experience with hood sash automatic closers?
Date: Wed, 24 Jun 2020 13:46:13 +0000
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID: db31849e003e420385a3702d3f3c5203**At_Symbol_Here**
In-Reply-To <000001d64a27$8035fc90$80a1f5b0$**At_Symbol_Here**>

Hello Richard and others reading this chain!


I am amazed at the content of this string, and in a good way! Lots of you have identified dangers in both large and small aspects of sash closers and variable air volume systems.


VAV can save lots of energy if designed, maintained, and operated properly. However, as you all have noted, many little things can become the "mice that roar".


You are all very dedicated and probably busy, so I'll attach another link below that tries to identify in an organized way the aspects of such systems which bear watching. I hope those of you who have the time to read this find it helpful.


Dr. Bob Haugen

Director of Product and Technology Development

Flow Sciences, Inc.


910 332 4878


Containment Products Get a Quote/Consultation Get Support/Replacement Parts


CONFIDENTIALITY NOTE: This e-mail, including all attachments, is directed in confidence solely to the person(s) to whom it is addressed, or an authorized recipient, and may not otherwise be distributed, copied or disclosed. The contents of this transmission may also be subject to intellectual property rights and all such rights are expressly claimed and are not waived. The contents of this e-mail do not necessarily represent the views or policies of Flow Sciences Inc. or its employees.


From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU> On Behalf Of Richard Palluzi
Sent: Wednesday, June 24, 2020 9:01 AM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Subject: Re: [DCHAS-L] Experience with hood sash automatic closers?


The replies to this initial request are, in my opinion, disturbing.  While I am sure we all have horror stores about our labs, I think there are some key issues people should remember and consider:


  1. The person designing your laboratory ventilation system needs to understand laboratory (as opposed to industrial) ventilation.
  2. You should insist on them complying with NFPA 45 Fire Protection for Laboratories Using Chemicals which, despite the title, has excellent overall ventilation requirements. ANSI/AIHA Z9.5 Laboratory ventilation is another excellent reference but, as it allows a lot more alternatives after further risk assessment, is more prone to being miss interpreted or miss applied.
  3. You should always have an independent laboratory design expert review your designer's proposed design for compliance and issues before approving construction.
  4. You should have a knowledgeable expert conduct a final QA/QC on the laboratory ventilation system after all the balancing is complete but before operation.
  5. You should consider laboratory safety audits, which should always include looking at the ventilation as it currently exists, every few years (3-5 is common).


While it is easy to blame the "designer", the "administrator", "management", "maintenance", or a host of other players for bad decisions  the sad truth is that most researchers have only a very weak idea of how their ventilation system really operates, the choices they can make when getting a new system including the advantages and disadvantages, and what they should be checking on what basis to ensure continued safe operations.


The University of Wisconsin offers a course that addresses these issues in detail along with many other design and safety aspects in Successful Laboratory Design: Grass Roots, Renovations, and Relocations. You can find more information at For further discussion you can also see  The Ten Most Common Laboratory Ventilation Mistakes at .



Richard Palluzi


72 Summit Drive

Basking Ridge, NJ 07920




From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU> On Behalf Of Meg Osterby
Sent: Tuesday, June 23, 2020 3:00 PM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Subject: Re: [DCHAS-L] Experience with hood sash automatic closers?


When the building that housed my chemistry lab at the institution where I taught for 17 years was remodeled several years before I arrived on the scene, the new hoods were installed onto the old vents, and the first time a sash alarm went off, the building administrator had all the wiring to the alarms REMOVED without telling anyone.  When I replaced him on his retirement, I was called into the lab by the insurance agent who was there to make sure all the safety systems were functional, and he wanted to know why he couldn't get the alarms to sound.  I said what alarms?  

Turned out that that same building admin had had the hood's power attached to the last light switch so if I 

"forgot to turn the hoods off, like when I was evaporating a flammable solvent or had a flask of chlorine gas in the hood for the next day's lab, then a janitor or security guard could make the decision to turn them off without consulting me.


My point is, just because those designers and managers and administrative people are in charge of those labs and those hoods DOESN'T MEAN THEY KNOW WHAT THEY ARE DOING.  For your own and your colleagues' and students' safety, you had better find out. It's not that they're trying to do dumb things, it's that they don't know enough of the science to realize just how stupid they are being.


Try to be tactful though.  That's not one of my strong suits, and it did eventually get me fired.  I made it 17 years, probably some kind of record for telling it like it is without worrying about stepping on toes.  I hope I'm a bit wiser today, but telling you all to watch your words and me remembering to might just be two different things.


Good luck.  This stuff can be really dangerous if done incorrectly, so do try to find out.  They need to know how to make it safe, and most of these folks don't come from science backgrounds.  My dean had never taken a hard science course since physical science in the 9th grade.  How was he qualified to supervise all the science courses?


Meg Osterby

Meg Osterby


On Tue, Jun 23, 2020, 9:38 AM Brown, Kimberly Jean <kimibush**At_Symbol_Here**> wrote:

[Cross posting to IH/Lab Safety and ACS DCHAS]

Hello all:


The architect and lab-planner consultants for an energy research building on our campus have recommended the installation of fume hoods with automatic sash closers.  Being an energy-research facility, there is obviously a focus on efficiency and sustainability in the design, and this is one of the proposed ways of making the labs greener.  


Having no first-hand experience with this these, our office is concerned about the practicality of these in devices in an academic laboratory setting.  Does anyone have any hoods like this on their campus?


Kimi Brown, ARM, NRCC-CHO, CSP

(she, her, hers)

Sr. Lab Safety Specialist/Chemical Hygiene Officer

215-746-6549 (Office)

215-651-0557 (Mobile/text)


EHRS is continuing to provide essential services with limited on-campus staff.  Those of us who are not on campus are working remotely to continue much of our normal operations.

Environmental Health and Radiation Safety

University of Pennsylvania

3160 Chestnut St., Suite 400

Philadelphia, PA 19104-6287


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