We have an area in a hospital where they use a type of glue called collodion and acetone as a solvent. They are sticking electrodes onto people in a neurophysiology lab, and using the acetone as a solvent to get it off of people. Both are group D materials with vapors heavier than air. In normal use, there could be an open container of the stuff, and it will be daubed onto patients to stick on electrodes, so there is no actual liquid transfer. However, in an accidental spill there could be a container of 16 ounces that would spill on the floor. There will be adequate mechanical ventilation to keep the vapors, in the event of a spill, below 25% of the Lower Explosion Limit.
We have decided that the exhaust fan will be a Class 1 Div 1 explosionproof motor, and the disconnect switch will also be class 1 Div 1 group D.
We are concerned about the room itself. Right now, it is a standard patient room. Most of the electrical outlets are four feet off the floor, lights are normal troffers. We are considering whether to classify the room itself as a CLass 1 Div 2 area (per NEC 500.5 (2) (2) ) up to 18" above the floor. I'd like to know if anyone has run into this situation and what the final decision on the classification of the room was.
We have decided that the exhaust fan will be a Class 1 Div 1 explosionproof motor, and the disconnect switch will also be class 1 Div 1 group D.
We are concerned about the room itself. Right now, it is a standard patient room. Most of the electrical outlets are four feet off the floor, lights are normal troffers. We are considering whether to classify the room itself as a CLass 1 Div 2 area (per NEC 500.5 (2) (2) ) up to 18" above the floor. I'd like to know if anyone has run into this situation and what the final decision on the classification of the room was.