In NFPA 45 Section 3.2.5 it states:

3.2.5 Shall. Indicates a mandatory requirement.

Since it is a part of the standard this trumps any other interpretation.

12.3.2.1.2 is clearly, at least in my opinion, intended to require that any demonstration " that involve or produce hazardous quantities of fumes, vapors, particulates, or gases" be done in a fume hood, demonstration hood, or similar properly designed ventilated enclosure.

12.3.2.1.3 requires you either provide separation (per12.3.2.1.4) or a shield. It tacitly assumes the demonstration does not " involve or produce hazardous quantities of fumes, vapors, particulates, or gases" or 12.3.21.12 would come into play.

Chapter 11 includes the need to evaluate the hazards of any new laboratory test or chemical reaction (11.2.1.1) and to do so with some frequency (11.2.1.3). As part of that hazard analysis and risk assessment, one could -perhaps - conceive a demonstration that, with additional mitigative measures, might be considered safe enough to do outside a hood even if it "involve(s) or produce(s) hazardous quantities of fumes, vapors, particulates, or gases". These additional mitigative measures might include trivial amounts involved and produced, additional local ventilation, shielding, separation, or other additional mitigative measures. However, it should be clear that one is then not strictly following NFPA 45 with increased attendant potential risk.

I would ask a more basic question. In today's video centric world why not do the demonstration without the students, inside a hood, capture it on video and show it to the students? One then has the chance to do the demonstration several times to ensure the best possible effect is produced, limits the audience which can be exposed to the hazard, and meet all the requirements of NFPA 45. I think most students are very used to observing videos and doubt the effect produced would be much less.

And, I remind everyone, that however much the feeling is that "it can't happen to me because I know what I am doing and will conduct a safe demonstration", the actual number of incidents does not readily support the view. The actual number of demonstration incidents annually suggests that additional safety measures beyond many currently being used are necessary to protect the participants.

Please note that while I am a member of the NFPA 45 committee, these comments reflect my personal opinions and not the committee's. For an official committee ruling you would need to follow existing NFPA procedures and contact the committee accordingly.

Richard Palluzi

PE, CSP

Pilot plant and laboratory consulting, safety, design,reviews, and training

www.linkedin.com/in/richardppalluzillc/

Richard P Palluzi LLC

72 Summit Drive

Basking Ridge, NJ 07920

rpalluzi**At_Symbol_Here**verizon.net

908-285-3782

From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU> On Behalf Of Margaret Rakas
Sent: Wednesday, April 10, 2019 4:13 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: [DCHAS-L] Interpreting NFPA 45 Section 12.3.2.1.2

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