From: David C. Finster <dfinster**At_Symbol_Here**WITTENBERG.EDU>
Subject: Re: [DCHAS-L] Estimating Teaching Lab Occupancy
Date: Sun, 10 Dec 2017 16:40:13 +0000
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Message-ID: CY4PR04MB071011D1CDD0918A036DA121B2360**At_Symbol_Here**CY4PR04MB0710.namprd04.prod.outlook.com
In-Reply-To


I, too, would like to review the work to which Jim refers.  Given all of the variables that can contribute to “severity and frequency of accidents” in a student lab setting, it’s hard for to believe that any research protocol and methodology could isolate “lab size” as a significant factor.  Intuitively, of course, such a correlation seems plausible.  As other have noted, the two driving forces I these are the “NFPA” goal of “exit capability”  (as well as “chemical load”) and/vs. the educational goal “fostering a safe and effective learning environment.”  These are completely different criteria for establishing a “safe” lab size and occupancy.   It’s hard for me to believe that the oft-quoted limit of 24 or 25 students/teaching lab has any basis other than “being reasonable.”  Perhaps the work by West-Moody will prove me wrong.

 

FYI, when we built new teaching labs about a decade ago, we designed our general chemistry labs spaces to hold 32 students.  (Part of the reason for this is that we enjoy the circumstance of having the same faculty instructor in the class and in the lab with the same group of students – which has tremendous educational value.  This is obviously not possible at large universities with very different staffing models.)  And, we have a faculty member (NOT a graduate TA who may or may not have the necessary, or ideal, teaching skills and safety attitudes as a faculty member) and an undergraduate TA in the lab for all lab sessions.  And, we excellent sight lines to all 32 students from almost every location in the lab.  And, we have an excellent pre-lab safety program that uses one of my favorite lab safety textbooks (!) including online, pre-lab safety quizzes and discussions and a comprehensive safety exam at the end of the semester.  Any single guideline for “students/teaching lab” cannot take into all circumstances of a laboratory (safety) program.  That said, I understand the desire for such a guideline, and 24-25 seems like a good starting point.  

 

I have greater concerns about lab size/occupancy in high school labs where, at the very least, student maturity is less than that for college students.  I have the impression that high school administrators sometimes bring great pressure to bear on expanding class (lab) sizes and we need to support HS chemistry teachers as they very reasonably resist such expansions based solely on safety concerns.

 

Dave

 

David C. Finster
Professor, Department of Chemistry
University Chemical Hygiene Officer
Wittenberg University
937-327-6441
http://userpages.wittenberg.edu/dfinster/index.html

 

From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Pam
Sent: Saturday, December 09, 2017 11:21 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] Estimating Teaching Lab Occupancy

 

Would you have a complete citation or a copy you could send me?

 

Pamela Auburn, PhD

2041 Branard

Houston TX 77098

 


From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU> on behalf of James Kaufman <jim**At_Symbol_Here**LABSAFETY.ORG>
Sent: Saturday, December 9, 2017 6:07 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] Estimating Teaching Lab Occupancy

 

Some of the best research that has been done on the relationship between both class room size and the student teacher ratio with the frequency and severity of accidents was done by Dr. Sandra West-Moody in the Biology Department at Texas State San Marcos.  ... Jim


James A. Kaufman, Ph.D.

President/CEO
The Laboratory Safety Institute (LSI)

A Nonprofit Educational Organization for Safety in Science, Industry, and Education

192 Worcester Street, Natick, MA 01760-2252
508-647-1900  Fax: 508-647-0062 
Cell: 508-574-6264  Res: 781-237-1335
Skype: labsafe; 508-319-1225 

jim**At_Symbol_Here**labsafety.org  www.labsafety.org

Teach, Learn, and Practice  Science Safely

 

 

On Sat, Dec 9, 2017 at 5:37 PM, Bruce Van Scoy <bvanscoy**At_Symbol_Here**twc.com> wrote:

Laurence,

Thank you for your observations based upon your experience.  I can only comment on the experiences that I observed. 

But, you presented  different perspectives that were equally, if not more significant than those that I experienced. 

In my case, I don’t remember the architect stamping all pages of the design with his license.

We had meetings, minutes with coordination/sign-off of the minutes following the meetings.  But in the end, we were left with prints that were “as designed” (equivalent to a Cadillac), not corrected to as-built which was equivalent to a Chevet.  The long-term observation is which is more important?  

I am surprisingly amazed that you were able to be involved in the contract requirements.  Very well done!

BruceV

 

From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Laurence Doemeny
Sent: Saturday, December 9, 2017 1:16 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] Estimating Teaching Lab Occupancy

 

I agree with everything that Bruce said in his reply to me.

 

Let me add a few comments based on my experience.

Make sure the architect has stamped all pages of the design with his license.

Be present at all discussions with the architect and engineers.

Get your critical needs addressed in the contract to avoid expensive contract modifications.

Be present on the walkthrough inspection when developing the punch- list prior to the final inspection and sign-off.

 

Laurence Doemeny

 

From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Bruce Van Scoy
Sent: Friday, December 8, 2017 3:15 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] Estimating Teaching Lab Occupancy

 

Laurence,

Prudent Practices was significantly revised in 2011 and is still available free from NAP.edu and maintained a basic  requirement (see section 9.B or pg. 213 or 9.C/pg. 219) for ventilation.  But Prudent Practices is to basic to be useful for design and you can’t rely on NFPA for occupational exposure control, their emphasis is fire prevention. 

I strongly recommend following ACGIH’s Industrial Ventilation: A Manual of Recommended Practice for Design, 29th Edition ALONG with Industrial Ventilation: A Manual of Recommended Practice for Operation and Maintenance, also 29th edition. 

I would also strongly recommend that if an architect acts as specified below, DOCUMENT, with citations AND copies to your attorney at every step….

And, oh by the way, if one happens to mention “value engineering” ensure that EHS has to sign off on ALL design changes in the contract language UP FRONT.  Otherwise, a design may turn into a bait and switch with significant differences between as designed v. as built.  Also, make sure they are keeping up with the as-built drawings.  You could find yourself looking at specifications/prints later that are totally inaccurate. 

Just my personal opinions,

BruceV

 

From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Laurence Doemeny
Sent: Friday, December 8, 2017 4:54 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] Estimating Teaching Lab Occupancy

 

This citation is probably dated but it is a good starting point.  the book has a chapter on laboratory design.

 

Prudent Practices in the Laboratory

 

From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Melissa Anderson
Sent: Friday, December 8, 2017 9:33 AM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: [DCHAS-L] Estimating Teaching Lab Occupancy

 

Hi DCHAS colleagues,

 

Does anyone know the best way to estimate occupancies for college teaching labs based on square footage and the exact sources for those estimates? I've seen several sources state 50 ft2 and cite the NFPA but I'm having trouble figuring out how to locate that specific information in the fire code. 

 

Also, does anyone know if that refers to gross or net (i.e. after benches/hoods/etc.) square footage?

 

If you want some context- I've include all the drama-laden details below.

 

Thanks,

Melissa Anderson

Instructor, Pasadena City College

 

 

Details for context (Warning: drama-ahead!): 

 

We're getting a new science building to replace our old building that was condemned for seismic issues. We just found out a month ago that the plans for the building were somehow finalized at the state chancellor's office without anyone's knowledge and that the submitted plans were designed in-house by someone in facilities rather than an actual architect. Based on our analysis, the new building will drop our lab enrollment capacity to almost 75% of what we can currently manage, which is 70% of what we where historically offering before our old building was condemned. (There are other issues, including that its five stories with one elevator.) We've been told very firmly that we can not make any changes to the building without losing our spot in the funding queue. (We're fine with this, the district board is not.)

 

When we talked to the architects about the square footage issue, they claimed that egress was the only issue for teaching lab occupancy and that they were unfamiliar with the 50 ft2/student value we were citing. [The architects were also rather mysteriously chosen since they didn't appear as one of the finalists selected by the committee. We've found several news articles about lawsuits involving code violations by this firm.)

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