Acetone is considerably less toxic than many other solvents. For one thing, it is not thought to be a carcinogen. The human body uses acetone as one of the ways of providing energy to the brain (fats and proteins cannot cross the blood-brain barrier so normally the only energy source for the brain is glucose - it there is a chronic shortage of glucose, the body breaks down fats into several different keytones, including acetone, which can then cross into the brain and be used for energy). I think, very roughly, a nastiness scale for vapor inhalation could be developed something like this (based loosely on US OSHA 8-hour time-weighted average permissible exposure level and my own experience): 0) Water 1) Ethanol (TWA PEL=3D1900 mg/m^3) 2) Acetone (2400 mg/m^3 but the effects of too much are nastier than Ethanol) 3) Ethyl Acetate (1400 mg/m^3) 4) Isopropanol (TWA PEL=3D1000 mg/m^3) 5) Diethyl Ether (1200 mg/m^3 but effects nastier than IPA) 6) Phenyls (Toluene, Xylene, about 400 mg/m^3 and possible carcinogens) 7) Tetrahydrofuran (another type of ether) 600mg/m^3 and carcinogenic 8) Chlorinated solvents (methyl chloride, dichloromethane, trichloromethane (chloroform), tetrachloromethane (carbon tetrachloride) - all carcinogens and range from 240 mg/m^3 (Chloroform) to 65 mg/m^3 for Carbon Tet. 9) Benzene (3 mg/m^3 TWA PEL) On Sun, May 18, 2014 at 8:13 PM, John Gardner wrote: > If it needs saying, acetone is quite toxic. > > To human beings, that is. Engineers, TBD... :) > > -- > > > Eppur, si muove... > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .