"Mixed messages" is an entirely accurate summary.
The standard for these cabinets is in NFPA 30, which has been revised repeatedly. In this standard, one method of certifying cabinets is ASTM E 119, which uses a firebox that heats the outer cabinet surface to an external temperature of around 1100 degrees F in 10 minutes. No portion of the cabinet interior can reach a temperature of 350 degrees F in this time frame to pass this test. If this cabinet is under active ventillation, this rigorous standard becomes highly problematic during a lab fire as heated air may be sucked into the cabinet by the ventillation system unless the external supply and exhaust air remain cool and flowing.
Since unvented cabinets frequently survive with their contents intact (see link below) many lab designers do not call out venting such cabinets. This is part of the reason venting is not required for such cabinets. Manufacturers usually provided covered vents which can be used at the customers' discretion. Please do not take any of this as an endorsement or criticism of venting. It does, however provide some history into lab design thinking.
Dr. Bob Haugen
910 332 4878
I am curious as to what your design standards are for new lab installs with UNDER HOOD flammable storage cabinets. Manufacturers sell vent kits for these to vent behind the baffles into the hood
and, back in my researcher days, most labs I worked in had under hood cabinets ventilated. NFPA advises against venting any flammable cabinets and I am getting mixed messages from various vendors and lab design teams. I have read a number of other university
design standards and they are also inconsistent.
What do your universities do? I usually recommend against venting standalone flammable storage but I am a bit torn on the under hood storage cabinets.
Brandon S. Chance, M.S., CCHO
Associate Director of Environmental Health and Safety
Office of Risk Management
Southern Methodist University
PO Box 750231 | Dallas, TX 75275-0231
T) 214.768.2430 | M) 469-978-8664
" our job in safety is to make the task happen, SAFELY; not to interfere with the work" Neal Langerman
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