The first comprehensive smoke-free law was implemented in Delaware in 2002, followed by New York in 2003
The 0.5mg figure comes from the emissions, which is the vapour each stick produces, and tends to be substantially lower than the nicotine content of the raw tobacco before its heated
No smoking signs or the international No smoking symbol consisting of a pictorial representation of a burning cigarette enclosed in a red circle with a red bar across it shall be clearly and conspicuously posted by the owner, operator, manager, or other person in control in every public building, public place, and place of employment where smoking is prohibited by this Part. Owners or managers can make outdoor areas at places of employment smoke free by posting signs prohibiting smoking despite the exemption of outside areas
There isnt enough research looking at these voice changes
3.Daily maintenance After each use, clean up the residue in time, including the steel tube (the steel tube can be disassembled and cleaned up), to increase the service life