I know that lime lights used to be used in theatres (I think) and that they were a fire hazard but otherwise.... I specifically need to know if they would be workable for an underground tunnel, a smuggling route for trafficking victims and suitable for lighting the immediate underground environment - would they give off toxic fumes? Would they trigger asthma attacks? I'm not worried about fire, it's an underground lair with rock supported by timber frames every 10 feet, 20 feet and the lights would be nowhere near the wood. TBH, I am asking before I hit up Google because I really don't want to wade through 10,000 pages of results if someone already knows but I am off to search Google now.... Thanks for any help!
They used "quicklime" (calcium oxide) for theatre lighting - I would think the light it produces would be too intense for your suggested use-case. It was also used for early car headlights! Any oxidising light such as the flaming torches beloved of the movies, candles, or quicklime would be problematic underground as they use up the oxygen. If your world doesn't have electricity, maybe look into phosphorescent (the re-emission of shorter wavelengths like microwaves at greater - visible - wavelengths) or luminous sources? Less light, but the eyes would become accustomed to the gloom after a while.
