Ethanol, chemically known as ethyl alcohol, is a compound used in solvents, fuels, beverage production, and medical applications. When purchasing “pure ethanol,” it is important to clarify the exact concentration and intended purpose, as the term usually refers to the highest commercially available grades. True 100% purity, known as absolute ethanol, is difficult to maintain because the substance readily absorbs moisture from the air (hygroscopic). For most practical purposes, the standard of high purity is 95% ethanol, or 190 proof, which is the highest concentration achievable through simple distillation. Purchasing this substance requires understanding purity levels, regulatory environments, and available retail channels.
Understanding Ethanol Purity Levels and Types
Ethanol concentration is commonly expressed as a percentage of alcohol by volume (ABV) or as “proof.” In the United States, the proof number is defined as twice the ABV percentage; for example, 95% ethanol is 190 proof. The highest concentration achievable using standard distillation is approximately 95.6% ABV. This is known as an azeotrope because the liquid and vapor phases share the same composition.
“Absolute ethanol” refers to a purity level of 99% to 100%. This concentration is achieved through specialized processes, such as azeotropic distillation using additives or chemical drying agents. This grade is reserved for laboratory or industrial procedures sensitive to water. Even absolute ethanol is hygroscopic and will absorb atmospheric moisture immediately upon exposure, making it challenging to keep at 100% purity.
A significant distinction for purchasing is whether the ethanol is undenatured or denatured. Undenatured ethanol, also known as pure or non-denatured ethanol, is a mixture of ethanol and water without toxic additives. Suitable for human consumption, food extraction, and pharmaceutical applications, this form is heavily taxed and regulated. Denatured ethanol has been intentionally rendered unfit for consumption by adding toxic or foul-tasting substances (e.g., methanol or isopropanol). This process does not alter the ethanol’s chemical properties for industrial use, but it exempts the product from beverage alcohol taxes. Denatured alcohol is cheaper and easier to acquire for applications like cleaning, fuel, and laboratory work where ingestion is not a concern.
Regulatory Frameworks for High-Proof Alcohol Procurement
Purchasing high-purity, undenatured ethanol is complicated because it is chemically identical to beverage alcohol, leading to significant governmental oversight. The federal government imposes a substantial excise tax on undenatured alcohol, regardless of whether it is intended for consumption or non-beverage use. This taxation is the primary reason for the high cost of pure ethanol compared to its denatured counterpart.
Businesses, academic institutions, or hospitals requiring large volumes of undenatured ethanol for non-beverage purposes can procure it tax-free through the Tax and Trade Bureau (TTB). These entities must secure a TTB Industrial Alcohol User Permit. This permit allows them to withdraw tax-free alcohol (190 proof or higher) for specific, regulated applications. The process ensures the alcohol is used strictly for non-beverage uses, such as scientific research or manufacturing, and requires strict adherence to record-keeping requirements.
The regulatory landscape is complicated by varying state-level restrictions on high-proof alcohol sales. Several states prohibit the retail sale of undenatured grain alcohol at or above 190 proof. These prohibitions are aimed at curbing alcohol misuse, but they limit options for individuals seeking high-proof ethanol for non-drinking purposes, such as making herbal tinctures or extracts. In these states, consumers may still purchase lower-proof grain alcohol or legally order 200-proof food-grade ethanol online for non-beverage applications.
Dedicated Retail Sources for Pure Ethanol
The source for pure ethanol depends on the required purity level and whether the buyer needs a taxed or denatured product. For the highest-purity, undenatured alcohol intended for human contact or consumption, consumer-grade liquor stores are a primary source. These retailers sell 190-proof grain alcohol, which is legally considered a beverage and includes all federal and state excise taxes in the price. This option is suitable for small-volume needs, such as culinary uses, food flavoring, and small-batch herbal extractions, provided the state permits the sale of this concentration.
For large-volume, industrial, or laboratory applications, the most cost-effective source is a chemical supply house or specialized industrial solvent supplier. These vendors predominantly sell denatured ethanol, including various formulations of Specially Denatured Alcohol (SDA). Buying denatured alcohol simplifies the process because it is tax-exempt and does not require a TTB permit for purchase. This makes it accessible for uses like equipment cleaning, manufacturing solvents, and fuels.
A third option for individuals and small businesses requiring food-grade, undenatured ethanol for non-beverage purposes is specialized online retailers. These companies provide high-purity 190-proof and 200-proof ethanol, often certified as USP/FCC Food Grade. They cater to users making tinctures, cosmetics, or topical products, simplifying the legal complexity by managing the federal excise tax payment and shipping compliance. This channel is useful for individuals residing in states where the retail sale of 190-proof grain alcohol is banned, as the ethanol is shipped legally under a non-beverage classification.