Do a search over the past few months of forum postings and you will find this has been thrashed to death

Evening Selina,

We have banned them during paid working hours and also on our industrial sites. For three reasons, firstly the act of smoking one of these things could be misconstrued at a distance and considered acceptable, in areas where it is unacceptable. Secondly they have a filament in the end which could be an ignition source during applications involving or in proximity to flammable substances. Thirdly, there is no attributable medical evidence that states that the by products are not harmful to neighbourhood workers. I hope this gives a bit of reasoning to banning them.

Regards
Alex