CVanadian Electrical code, 2006 Edition.
Section 0, Object, scope, and definitions
Intrinsically safe - that any spark or thermal effect that may occur in normal use, or under any conditions of fault likely to occur in practice, is incapable of causing an ignition oif the prescribed flammable gas, vapour or dust.
I doubt that even the vibrator motor used in a cell phone could be made intrinsically safe.
Intrinsically safe circuits are very low power signal circuits.
What you want electrically is an explosion proof motor and electrical installation in the hazardous areas that is appropriate for the hazardous substances that will be used.
That covers the electrical aspects, but you are still left with the mechanical issues. If the rotating fan contacts the housing due to any type of failure, is it capable of generating sparks.
Will the friction of a rubbing fan cause a high enough temperature to ignite the hazardous substance.
I would first locate the solvents in the local code and determine the class and group.
Then look for a complete motor-fan unit that is approved for the class and group. Do the same for the lighting fixtures, switches and controls. Your codes should indicate an area around the fume hood that is considered hazardous. Any and all electrical equipment within this area must be rated for the proper class and group. Don't forget that in some cases the area around the ducting may be considered hazardous.
This is just the electrical aspects of a fume hood. The fire marshal will have regulations for the location of the ducts and the disposal of the hazardous substance.
I think that the success of your project depends on your ability to find a motor and fan combination that is acceptable at an affordable price.
I would be searching for an approved fan and motor, and I would drop in on the local fire marshal to discuss the usability of the vent hood. He may be able to give you a simple yes or no. (What is the thickness of the material? Are the seams spot welded or continously welded? What was the previous use?) These questions may be more important (expensive?) than the electrical questions.
Google "explosion proof fans"
As well as conventional fans with explosion proof motors and non-sparking blades, you will find air-motor driven fans and venturi fans. A normal motor and fan, located outside the hazardous area push fresh air through a venturi which collects and exhausts the fumes.
BTW, I once connected an exhaust hood for a large institutional kitchen. The electrical inspector passed the electrical work completely. No problems electrically. Then the building inspector condemned most of the mechanical installation for multiple code violations. The complete ducting system had to be rebuilt.
I don't want to discourage you, you may be able to meet the codes easily, but there are pitfalls. Be careful and watch your ASSets.
respectfully
When you have completed your research, submit your proposal to your company's legal department and/or the insurers.
