Posted for Steve:

I've been a Stage LX for several years in Canada, but I'm assuming the rules are the same down there. We generally used Strand or ETC luminaires-all carry the UL(CSA) label.So do their dimmers.This would be required for import, and use in a public place.It would be common sense to use Listed products in this environment. Theatres are terrible fire traps to begin with. this is not to say I've not done some pretty risky things when the time and $$$ were at a premium !
Most theatres I've worked in have some very old luminaires with asbestos Ins.-over a few seasons,, we would slowly replace them with THHN, and a polyester sleeve-understandably, this can be a long procedure, and expensive, but I feel it should be done.I've never had a complaint from anyone in authority if some of the luminaires still had asbestos insulation.

We used to run a lot of low V. around the stage, and I always treat it as if it was 110/220-protect the public and the cast(and expensive equip)at all costs.

Equipment and conductors must be approved by the authority having jurisdiction. This does not necessarily mean UL Listed. The criteria used for what to accept and what not to accept is up to the AHJ. (usually this is a UL listing but doesn't have to be)
See above