Posted 01 March 2009 - 05:49 PM
Thank you very much.
Posted 01 March 2009 - 06:13 PM
So for tax reason, industry tends to use denatured ethanol.. as it is now classified as a chemical and not a potential alcoholic beverage (Although that doesn't stop some, resulting in blindness etc).
In molecular biology use, as denatured ethanol contains impurities (biterax-most bitter substance known to man, methanol, or other compound), it is usually only used to sterile bench surfaces and skin.
All other purposes where the ethanol has to comes into contact with your cells, DNA etc, should be HPLC grade ethanol (pure undenatured ethanol).
Posted 02 March 2009 - 03:53 AM
Most cosmetic uses of alcohol use SD (special denatured) 40 ethanol - denatured with brucine and tert butyl alcohol. Brucine is obtained from plant material - primarily from India. It comes in with low levels of strychnine (brucine is dimethoxy strychnine). In the early 90's the crops had elevated levels of strychnine - so the brucine material had excessive strychnine. Alcohol manuf's shut down SD40 production for about 6 months until FDA determined even the elevated level was still safe. Since SD40 was on ingredient labels and false labeling was no small infraction, "old" SD40 very went for a huge premium during that period. Next year's crop was back to historic levels and the problem never came back up.