The seal requirements for Class I locations [501.15] are more detailed and extensive than those for Class II locations [502.15]. The difference is this: Class I addresses the presence of combustible (or flammable) vapors, while Class II addresses the presence of combustible dust. It’s much harder to control vapors than dust, so Class I requirements are more stringent than Class II. If the location has vapors, apply Class I.


Safety
Even legal drugs can have catastrophic consequences in electrical work. You don't want to be slow to react or hyperactive when working on live circuits or equipment. Some common examples:

• Antihistamines. If the label says it “may” make you drowsy, don’t take it before or during work.
• Decongestants. Typically, a decongestant speeds up your entire system. Its effects are comparable to those of other stimulants, such as coffee or diet pills.
• “Energy” drinks (e.g., Jolt, Red Bull). It’s safer to overcome “the drowsies” by going to bed earlier rather than by caffeine overload.

One choice is to add more circuits to accommodate the heaters and other devices. Another is to simply turn up the thermostat. The first choice will require an investment in labor and material, and it will be more energy-consumptive than achieving the same effect per the second choice. Management needs to decide if it wants the appearance of green based on an unrealistic thermostat setting, or if it wants to actually be green.