Undenatured Ethanol

About Undenatured Ethanol

Undenatured ethanol is ethanol that does not have denaturants added to deter ingestion, making it safer, but also subject to excise taxes. Undenatured ethanol does not necessarily mean food grade. Within the undenatured category, ethanol purity may still vary depending upon the application since byproducts might form during ethanol production or storage.

The most obvious impurity is water. Ethanol and water form an azeotrope, which means that no matter how many times you distill it, the maximum concentration you can achieve is 95.6% ethanol.

Ethanol is also hygroscopic, and will absorb water from the atmosphere even if it has been completely purified. Water may also be added intentionally to change the concentration of the ethanol. For example, undenatured ethanol is often used for hand sanitizer since it may come into contact with food, but 100% ethanol (called absolute ethanol) is an ineffective disinfectant.

Optimal concentration of ethanol for sanitization is between 60-80% to denature viral proteins. For ethanol dilutions, volumes are not additive, due to the intramolecular forces between ethanol and water.