What is Reagent Alcohol?

The sale of ethyl alcohol is regulated by the Alcohol, Tobacco and Firearms Agency. The ATF wants to be sure that one is not purchasing ethanol for lab use and diverting it to beverage use without paying the tax. It is possible to purchase pure ethyl alcohol, but there are severe record keeping and tax restrictions. In order to avoid the taxes and/or record keeping, the ATF authorizes the use of denatured alcohol for laboratory use. Denatured alcohol is ethanol with something added to make it undrinkable. Denatured alcohol is also referred to as "SD" alcohol (for specially denatured).

The purest of the denaturing formulas is SD3A, which is 95% ethanol with 5% methanol. SD3A is authorized for manufacturing use at facilities that are licensed for its use. It may not be sold to the general public. The purest authorized denaturing formula that may legally sold to the public is reagent alcohol, which is 95% SD3A with 5% isopropanol. Reagent alcohol is a suitable replacement for pure ethanol in almost all laboratory procedures. The only exceptions we are aware of are: The preparation of alcohol standards (obviously), and drug use.