The following is the perspective from our emergency response team leader re: the need for emergency purge buttons for rooms and hoods.  Thank you all for your responses and comments  on this issue.

Best regards,

Yung I would add from my perspective the following

Our office has been involved in campus wide emergency response for over 30 years. We maintain 24/7 coverage and operate a full HAZWOPER team. The fire department along with the State HAZMAT team expect us to be on scene to help assess and evaluate any ER to the campus.

For chemical spills in laboratories we generally respond in house and clean these up under our HAZWOPER protocols. The fire chief has worked well with us and wants to be in the loop and is available if we need him. We train with the fire department and the state HAZMAT team on a regular basis. I think maintaining that relationship and fostering the sense of confidence allows you to maintain control of your buildings and your operation. When we request assistance from these groups it is generally a Unified Command Structure with our staff participating in the decision making process. These efforts take considerable time and effort but have paid off in major incidents.

Now to laboratory purge systems.

As the Incident Commander directing an entry I would prefer to have my entry team enter a room with the lowest readings possible. We do not allow entry if readings are at 10% of the LEL and I would prefer that measurements if available are below any IDLH. Our first call as we respond to a spill is to ask if the room is on full purge. If the occupants did not activate the room purge as they evacuated our HVAC people can activate these emergency purges room by room or floor by floor depending on what has occurred. With modern day controls our HVAC staff can operate these from home at any time of the day or night. This simple action makes the room extremely negative and keeps the hot zone small. We allow the purge to continue as our team suits up and we develop our Incident Action Plan. This can take up to an hour or more for an off shift response. The longer the purge is running the better as far as the entry team is concerned. Our initial entry is normally simple, SCBA is a requirement along with robust level B suits. We enter with multiple detector devices usually both PID and multi gas readings are taken. Assess the size and complexity of the spill. Determine the accuracy of what is reported to be spilled and spread adsorbent onto any spilled liquid materials.

As the IC responsible for the safety of the entry team it has been extremely useful to have the room at 12 air exchanges per hour while you prepare for entry. The idea the you can keep the hot zone to a room or a floor is a great asset that can minimize potential exposure and allows the entry team to setup at the lab door versus outside the building. The issue of responder safety whether it is our group, the fire departments or the HAZMAT team is paramount and should be considered when designing a laboratory. These full exhaust emergency purge operations are not run during normal operations and are generally activated by the occupants as they leave the lab during a spill. I am convinced after 30 years of spill response that this simple addition to the building design reduces potential exposure to occupants as they leave and minimizes the potential hazard to the first responders. It allows the response to be conducted with more confidence and minimizes the duration of the spill clean-up.  Our energy engineers were at first reluctant participants but now see the value of these seldom used tools. The last time we trained with the district hazmat team they loved the ability to bring the cold zone up to the lab door and questioned why this was not a design standard for all laboratories.

It seems we have this fight with all design engineers when we build new or renovate any old lab buildings. We go through the same argument every time.

Loss of energy efficiency! How often do you expect to use this tool?

Creates turbulence and could draw chemical vapors out of the hood! No one should be in the lab at this point! We are trying to exhaust the room not the hood.

Talk to first responders and ask them, when making an entry to the hot zone with full protective gear and SCBA do you want to enter a room saturated with vapors at or above the LEL or the IDLH or one the gives you no reading or a very low readings.

Its relatively simple to do during the design build process and the cost is negligible. It just makes sense.

Jim

emailjmfield**At_Symbol_Here**ehs.umass.edu

From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU]On Behalf Of Monona Rossol
Sent: Tuesday, August 13, 2013 10:06 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: Re: [DCHAS-L] Fume hoods purge buttons