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Understanding Denatured Alcohol

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Understanding denatured alcohol

When using alcohol in your products, you will often hear the distinction between pure alcohol and denatured aclohol. But what exactly is denatured alcohol? And how does it differ from pure ethanol?

What are denatured alcohol and denaturants?

Essentially, denatured alcohol is ethanol rendered unfit for human consumption by mixing in denaturants. A denaturant is a chemical ingredient that makes the ethanol unpalatable and gives it an unpleasant taste or smell. There are several types of denaturants that are used worldwide, and several reasons why they play such a big role in the ethanol distribution industry.

Nedstar's selection of denaturants
Nedstar cleaning

The need for denatured alcohol

Ethanol has numerous applications across many different industries, from food, beverages and personal care to pharmaceuticals and electronics. Most countries place excise taxes on any alcohol that can be used in alcoholic beverages or food, but ethanol that can’t be used for human consumption is exempt from these excise duties. So, for customers that are in need of ethanol for non-food purposes, such as in the industry sector, alcohol is denatured to ensure that it can’t be used for human consumption and therefore won’t be subject to excise duties.

Types of denaturants

At Nedstar, we use several different types of denaturants to denature your alcohol. Check out our selection of denaturants here.

Next to the ones Nedstar offers, there are various other types of denaturants used in ethanol, each with its own properties and applications. Some of the most common denaturants include:


Also known as isopropyl alcohol or IPA, isopropanol is a colorless, flammable liquid that is not only used as a denaturant for ethanol, where adding even small amounts (3%, 5%, or 10% of the total mixture) renders the ethanol unfit for consumption, but also as a solvent and disinfectant. Being less toxic than methanol, isopropanol is often used in personal care products.

Methyl ethyl ketone

Methyl ethyl ketone, or MEK, is a colourless, flammable liquid used as a solvent and in the production of resins and coatings. MEK is also used as a denaturant for ethanol, where a small amount - usually 1% - makes the ethanol unfit for consumption; it is especially popular in the German market. MEK has a strong odour and can irritate the eyes and skin.

Denatonium benzoate

Denatonium benzoate, better known as Bitrex, is a bitter-tasting chemical used more or less exclusively in ethanol denaturants. Bitrex is not toxic but is extremely bitter and likely to cause nausea and vomiting if ingested, which is why it is a popular denaturant.

Diethyl phthalate

Diethyl phthalate (DEP) is a colorless, odorless liquid. Next to acting as a denaturant, DEP is often used as a plasticizer, solvent or fixative in, for example, cosmetics, fragrances and personal care products.

Euro denaturant

Euro denaturant is an ethanol denaturant mix used in the EU. It is a mixture of various denaturants, including isopropanol, MEK and denatonium benzoate. As the name suggests, euro denaturant is regulated by the EU’s REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), which sets out rules for the use and handling of chemical substances, including euro denaturant. Using other denaturant formulas in the EU requires different excise licenses. Denatured alcohol that is euro denatured is also called ‘completely denatured alcohol’.

Tertiary butyl alcohol

Tertiary butyl alcohol, or TBA, is another commonly used ethanol denaturant. It is a clear, colorless, highly flammable liquid with a strong odor. Denatured TBA ethanol is widely used in industry, for example in the production of solvents, adhesives and coatings. The key benefit of TBA is its low boiling point, water-soluble properties and being less toxic than many other denaturants.


Linalool is a terpene alcohol naturally occurring in many plants, including lavender, mint and citrus. It has a pleasing floral scent and is therefore often used in perfumes, cosmetics and aromatherapy. It also works as a relatively mild, low-toxicity denaturant for ethanol. Linalool has not been as much of a popular ethanol denaturant as some of the other denaturants listed in this article, but that may start to change as many see it as an eco-friendly alternative.

TSDA 1-9

TSDA 1-9 are nine different blends of denaturants commonly used in ethanol, including, among others, isopropyl alcohol, MEK and denatonium benzoate. TSDA 1-9 are used in a wide range of industrial and scientific applications that don’t require the use of pure ethanol.


Methanol is a colorless, flammable, highly toxic liquid that can cause blindness or even death if ingested. Adding only 5% of the total amount to ethanol renders it unfit for human consumption. Aside from being one of the most popular denaturants for ethanol, methanol is also used as fuel and feedstock for chemical production.

Partially vs completely denatured alcohol

The term ‘partially denatured alcohol’ is commonly used in the European Union and refers to alcohol that is denatured with only one denaturant or a different mix of denaturants than Euro denatured. Euro denatured alcohol is therefore considered to be completely denatured. Partially denatured applies to denatured alcohol in products not intended for human consumption but for which the rules on completely denatured alcohol are not suitable. Examples of such products are cosmetics, perfumes, hygiene products, bio-fuels, screen wash, anti-freeze, inks, and cleaning material.

Can denatured alcohol be transformed into pure alcohol again?

While it is technically possible to transform denatured alcohol back into pure alcohol, it is highly regulated or even illegal to do so in many countries. As a general rule, the chemicals involved in the denaturation process are specifically chosen to make it difficult and impractical to reverse denaturation.

Nedstar denaturants mixing

Denaturants - here to stay

Denatured alcohol has numerous applications across many industries. Aside from its useful physical properties, denatured ethanol owes much of its rapidly growing popularity to the lower excise duties it carries. However, the amount of different chemicals used and regulations around denaturation are highly dependent on the country and economic region, increasing the risk of misunderstandings. With experienced ethanol distribution partners such as Nedstar, customers can source suitable alcohol products for their industries with more ease and without compromising on quality.