Glycerin, taken orally, has roughly the same LD50 as table salt from the MSDS I'm looking at (glycerin = 4090 mg/kg LD50 orally for mice versus 4000 mg/kg for t

Glycerin, taken orally, has roughly the same LD50 as table salt from the MSDS I'm looking at (glycerin = 4090 mg/kg LD50 orally for mice versus 4000 mg/kg for table salt)[1][2], lest we start a panic. Second-hand smoke is generally accepted as a bad thing, as is wood smoke, unsurprisingly. I've seen suggestions that wood smoke may be even worse simply on the merit that a great volume of nasty compounds are released, and the particulate material is substantially smaller (due to the higher combustion temperatures) and can enter more deeply into the lungs[3]. If it's a choice between cigarettes and someone sucking down glycerin vapors, I think I'd be much happier to accept the latter. [1] http://www.sciencelab.com/msds.php?msdsId=9927350 http://www.sciencelab.com/msds.php?msdsId=9927350 [2] http://www.sciencelab.com/msds.php?msdsId=9927593 http://www.sciencelab.com/msds.php?msdsId=9927593 [3] http://www.ehhi.org/woodsmoke/health_effects.shtml http://www.ehhi.org/woodsmoke/health_effects.shtml