What is the Difference Between Methylated Spirit and Surgical Spirit

The key difference between methylated spirit and surgical spirit is that methylated spirit is used mainly for the removal of stains and as a fuel in small lamps and heaters, whereas surgical spirits are useful as a disinfectant, in preventing bedsores, and for hardening the skin of the feet.

Both methylated spirits and surgical spirits are useful alcoholic liquids. They have nearly similar chemical compositions, but they are used in different applications.

CONTENTS

1. Overview and Key Difference
2. What is Methylated Spirit  
3. What is Surgical Spirit
4. Methylated Spirit and Surgical Spirit in Tabular Form
5. Summary – Methylated Spirit vs Surgical Spirit

What is Methylated Spirit?

Methylated spirits are alcohols that are made unfit for drinking by the addition of about 10 percent methanol. Typically, methylated spirits contain some pyridine and a violet dye. These liquids are also called denatured alcohol, meaning ethyl alcohol is mixed with other chemical substances, including chemicals like methanol, methyl isobutyl ketone, and benzene. This liquid is highly toxic due to the addition of toxic substances such as methanol; thus, this liquid is not suitable for human consumption.

Furthermore, methylated spirits are colourless solutions. We can colour these solutions by adding aniline. This colouration is important to easily recognize the methylated spirit. After the addition of aniline, the liquid appears in a violet colour. Moreover, the presence of ethyl alcohol and methanol makes methylated spirits toxic, extremely flammable, and volatile. Our skin can absorb this liquid due to the presence of methanol. Due to this reason, we cannot use this liquid to make perfumes or bath products. Moreover, methylated spirit has a bad odour and poor taste as well.

Methylated spirit is important as solvents, hand sanitizers, cosmetics, and as fuel for heating, lighting, etc. There is a colourless form of this liquid that is important in killing mildew on leather surfaces. In addition, we can use methylated spirit as a solvent for dissolving compounds like glue, wax, and grease. As this liquid does not react with glass, we can also use it for window cleaning. Although it is not good for human consumption, it is still important in cosmetic production due to its antibacterial activity.

What is Surgical Spirit?

Surgical spirit, rubbing alcohol, or denatured ethanol is a form of ethanol containing a high amount of additives and denaturants, which makes it poisonous. In surgical terms, we often use the term surgical spirit. This chemical has an unpleasant taste and a foul smell. Sometimes there can be some additives such as dyes to distinguish denatured ethanol from undenatured ethanol. The process of denaturing ethanol to make surgical spirit does not alter the chemical structure of ethanol nor decompose it. In this production process, ethanol is only altered to make it undrinkable.

The additives used in producing this type of ethanol are methanol, isopropanol, and pyridine. These compounds are useful to get a poisonous solution, and sometimes denatonium is useful to make the solution bitter. The purpose of producing surgical spirit is to reduce recreational consumption and to reduce taxes on alcoholic beverages. The traditional additive used for this type of spirit is 10% methanol. Denatured ethanol is cheaper than undenatured forms of ethanol.

What is the Difference Between Methylated Spirit and Surgical Spirit?

Both methylated spirits and surgical spirits are useful alcoholic liquids. The key difference between methylated spirit and surgical spirit is that methylated spirit is used mainly for the removal of stains and as a fuel in small lamps and heaters, whereas surgical spirits are useful as a disinfectant, in preventing bedsores and for hardening the skin of the feet.

The below infographic presents the differences between methylated spirit and surgical spirit in tabular form for side by side comparison.

Summary – Methylated Spirit vs Surgical Spirit

Methylated spirits and surgical spirit are useful alcoholic liquids. They have nearly similar chemical compositions, but they are used in different applications. The key difference between methylated spirit and surgical spirit is that methylated spirit s used mainly for the removal of stains and as a fuel in small lamps and heaters, whereas surgical spirits are useful as a disinfectant, in preventing bedsores and for hardening the skin of the feet.

Reference:

1. “Surgical Spirit BP – Summary Of Product Characteristics (Smpc) – (Emc)“. Medicines.Org.Uk, 2022.

Image Courtesy:

1. “Borse-percept-antiseptic-medical” (CC0) via Pixabay
2. “Rubbing Alcohol (51013600587)” By ajay_suresh – Rubbing Alcohol (CC BY 2.0) via Commons Wikimedia