What is the Difference Between Denatured and Undenatured Ethanol

Ethanol, a chemical compound widely used in various industries, exists in two main forms: denatured and undenatured. Despite sharing the same chemical composition, their intended uses and properties differ significantly. Understanding the difference between denatured and undenatured ethanol is essential for various industries, regulatory bodies, and consumers.

What is the difference between denatured ethanol and undenatured ethanol? Denatured ethanol contains additives that make it unfit for consumption, whereas undenatured ethanol is pure and suitable for consumption.

Key Areas Covered

1. What is Denatured Ethanol
      – Definition, Features, Applications
2. What is Undenatured Ethanol
      – Definition, Features, Applications 
3. Similarities Between Denatured and Undenatured Ethanol
      – Outline of Common Features
4. Difference Between Denatured and Undenatured Ethanol
      – Comparison of Key Differences
5. FAQ: Denatured and Undenatured Ethanol
      – Frequently Asked Questions

Key Terms

Absolute Ethanol, C2H5OH, Denatured Ethanol, Pure Ethanol, Undenatured Ethanol

Difference Between Denatured and Undenatured Ethanol - Comparison Summary

What is Denatured Ethanol

Denatured ethanol is a type of ethanol (ethyl alcohol) that has been rendered unfit for human consumption by the addition of denaturing agents. These agents are often bitter or foul-tasting substances, such as methanol or denatonium, making the ethanol undrinkable and thus discouraging recreational use. The denaturation process is crucial for regulatory compliance and safety, as it prevents the diversion of ethanol for illicit purposes.

Commonly used in various industrial applications, denatured ethanol serves as a solvent and cleaning agent. Its ability to dissolve a wide range of substances, from fats and oils to resins and pigments, makes it valuable in manufacturing processes, pharmaceuticals, and cosmetics. Additionally, denatured ethanol finds application in the production of personal care products, paints, and varnishes.

Denatured Ethanol

Due to its effectiveness as a disinfectant, denatured ethanol is utilized in healthcare settings for surface disinfection and medical equipment sterilization. It has gained prominence, especially during times of increased hygiene awareness, as a key component in hand sanitizers.

Despite its industrial significance, precautions must be taken when handling denatured ethanol due to its flammable nature. Adequate ventilation and proper storage conditions are essential to ensure a safe working environment.

What is Undenatured Ethanol

Undenatured ethanol, also known as pure ethanol or absolute ethanol, is a highly pure form of alcohol containing a minimal amount of water. With a chemical formula of C2H5OH, it is a colorless and flammable liquid renowned for its uses across various industries. One of its primary applications is as a solvent in laboratories, where its purity ensures accurate and uncontaminated results in scientific experiments.

In addition to its role in research, undenatured ethanol is a key component in the pharmaceutical and cosmetic industries. It serves as a solvent for various drugs and is employed in the manufacturing of medicines, tinctures, and personal care products. The absence of denaturing agents in undenatured ethanol makes it suitable for applications where absolute purity is essential.

Undenatured Ethanol

Furthermore, undenatured ethanol is utilized in the production of alcoholic beverages, acting as the main ingredient during the fermentation process. Its purity contributes to the quality and flavor profile of the final product. Additionally, the stringent regulations and quality standards surrounding undenatured ethanol highlight its significance in ensuring the safety and integrity of the products it is used in.

Similarities Between Denatured and Undenatured Ethanol

  1. Denatured and undenatured ethanol have the same chemical formula, C2H5OH, consisting of two carbon atoms, six hydrogen atoms, and one hydroxyl group.
  2. Both types of ethanol are generally produced through the fermentation of sugars by yeast or through chemical synthesis.
  3. They share similar physical properties, such as volatility, flammability, and solubility in water.
  4. Both denatured and undenatured ethanol are used in various industrial applications, including as solvents, fuel additives, cleaning agents, and antiseptics.

Difference Between Denatured and Undenatured Ethanol


  • Denatured ethanol is ethanol that contains additives or denaturants, such as methanol or other chemicals, making it unsuitable for consumption. Undenatured ethanol is pure ethanol without added denaturants, making it suitable for consumption in regulated amounts.


  • Denatured ethanol is typically used for industrial or commercial purposes, such as cleaning, manufacturing, or as a fuel additive, while undenatured ethanol is used in products for human consumption, like alcoholic beverages, pharmaceuticals, or food flavoring.


In summary, denatured ethanol, modified with denaturing agents, is utilized across various industries, including manufacturing and healthcare, serving as a solvent and disinfectant. Conversely, undenatured ethanol, in its pure form without denaturants, is employed in pharmaceuticals, cosmetics, and alcoholic beverages. While both act as solvents and fuels, the cost-effectiveness of denatured ethanol makes it preferable for non-consumable purposes. It’s essential to handle denatured ethanol with caution due to its flammability. The difference between denatured ethanol and undenatured ethanol depends on the intended application, balancing purity and functionality across different industries.

FAQ: Denatured and Undenatured Ethanol

1. Why is denatured alcohol used instead of ethanol?

Denatured alcohol is chosen over ethanol mainly because it’s cheaper for non-consumable applications. By changing its composition, denatured alcohol avoids beverage alcohol taxes and regulations, reducing production expenses.

2. What are the 4 types of alcohol ethanol?

The 4 types of alcohol are isopropyl alcohol, methyl alcohol, undistilled ethanol, and distilled ethanol. Isopropyl alcohol is commonly used as a disinfectant, solvent, or cleaning agent. Methyl alcohol is highly toxic to humans and is primarily used industrially as a solvent and antifreeze. Undistilled ethanol is ethanol that has not undergone purification processes, while distilled ethanol has undergone purification processes to increase its purity.

3. What is another name for denatured alcohol?

Denatured alcohol is also known as methylated spirits. Methylated spirits typically contain ethanol mixed with a denaturant, such as methanol or other additives.  This term is commonly used in various regions, especially in the United Kingdom and some Commonwealth countries.

4. Why is 100 ethanol not used?

The main reason 100 ethanol or pure ethanol is not commonly used as a fuel is concerns about human consumption. If pure ethanol were readily available, there would be a significant risk of misuse or accidental ingestion, which could lead to severe health consequences or even fatalities.

5. What is 70% ethanol?

70% ethanol is a solution containing 70% ethanol (ethyl alcohol) and 30% water. Moreover, 70% ethanol is commonly used as an antiseptic in laboratory environments. It has the highest effective concentration at 70% compared to 95% or 100%.


1. “Denatured Alcohol.” Wikipedia. Wikipedia Foundation.

Image Courtesy:

1. “Denatured alcohol” By Dluuc – Own work (CC BY-SA 4.0) via Commons Wikimedia

2. “Sample of Absolute Ethanol” By LHcheM – Own work (CC BY-SA 3.0) via Commons Wikimedia

About the Author: Hasini A

Hasini is a graduate of Applied Science with a strong background in forestry, environmental science, chemistry, and management science. She is an amateur photographer with a keen interest in exploring the wonders of nature and science.

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