Classifying an area?

[zeilzabob]

I have an enclosed hood that has a VFD driven exhaust fan. When the door opens the drive increases the negative pressure of the hood to help with the removal of fumes. I want to know how to classify the area around the hood when the door is open.

Parameters
1. Inside the hood is class 1 div. 1
2 Chemicals in hood -Methanol, Propolene, tetrohydrofuran
3. The hood is totally self contained (certified) when the glass front is closed.
4. The VFD increases to 6000 air exchanges per minute when the hood is opened.

Is the boundry 10'?
What is its classification and where can I verify this with documentation?
Or simply is it not classified.

Thanks

 

[rbalex]

The applicable standard is NFPA 45, Standard on Fire Protection for Laboratories Using Chemicals. In general, a facility built to this Standard will not need electrical area classification outside the hood. The Standard is fairly lengthy though and should be consulted before any final determination is made.