Table of Contents

• Introduction
• What is Ethanol?
• Why is Ethanol Used in Hand Sanitisers?
• Understanding the Importance of 99.9% Purity
• Process of Incorporating Ethanol into Hand Sanitisers
• Safety Considerations
• Ethical and Environmental Considerations
• Conclusion
• References
• FAQ

Introduction

Hand sanitisers have become an integral part of our lives, especially during times when maintaining high standards of personal hygiene is crucial. The core ingredient of most hand sanitisers is ethanol, particularly those of 99.9% purity. This comprehensive guide aims to explore the role of this key component in hand sanitiser production, its importance, and how it is incorporated into the final product.

What is Ethanol?

Ethanol, also known as ethyl alcohol, is a volatile, flammable, colorless liquid. It’s the active ingredient in alcoholic drinks, but it’s also widely used in industry and medicine for its disinfectant and antiseptic properties.

Why is Ethanol Used in Hand Sanitisers?

Ethanol acts as an effective germ killer. It works by denaturing proteins in microorganisms, leading to cell death. Ethanol-based hand sanitisers typically contain between 60% and 95% alcohol, which is sufficient to kill most types of bacteria, viruses, and fungi without causing harm to human skin.

Understanding the Importance of 99.9% Purity

In the context of hand sanitiser production, using ethanol of 99.9% purity is important for two main reasons:

Effectiveness: The higher the purity of the ethanol, the more effective it is at denaturing proteins and killing microorganisms. Lower purity ethanol may contain impurities that dilute the alcohol concentration and reduce its germ-killing efficacy.

Safety: Ethanol impurities, depending on their nature, could be harmful to the skin or pose health risks. Using high-purity ethanol minimizes the risk of including such harmful substances in the final product.

Process of Incorporating Ethanol into Hand Sanitisers

The typical process for creating hand sanitiser involves these steps:

Ethanol Dilution: The 99.9% pure ethanol is first diluted with distilled or deionized water to achieve the desired concentration.

Addition of Humectants and Emollients: Humectants such as glycerol are added to prevent the alcohol from evaporating too quickly, thus ensuring it remains on the skin long enough to kill germs. Emollients are added to moisturize the skin and prevent it from drying out.

Addition of Thickening Agents: To give the hand sanitiser a gel-like consistency, thickening agents like carbomer areadded.

pH Adjustment: The pH is adjusted using a base, such as triethanolamine, to ensure that the final product is not too acidic and therefore not irritating to the skin.

Addition of Fragrance and Coloring Agents (Optional): Fragrances and coloring agents can be added to improve the aesthetic appeal of the hand sanitiser. These should be skin-friendly and non-irritating.

Mixing and Homogenization: All the ingredients are mixed together and homogenized to ensure a uniform distribution of components within the mixture.

Quality Control: The mixture is tested to ensure it meets all necessary quality standards before packaging.

Packaging: The final product is packaged into suitable containers, typically plastic bottles with pump dispensers or flip caps.

Safety Considerations

Ethanol is a volatile, flammable liquid and should be handled with care. When producing hand sanitisers, it’s important to work in a well-ventilated area away from open flames or sparks. Appropriate personal protective equipment, such as gloves and eye protection, should be worn to protect against splashes.

In the finished product, ethanol can cause skin irritation in some individuals, particularly with repeated use. Therefore, it’s recommended to include skin-soothing and moisturizing ingredients in the formulation.

Ethical and Environmental Considerations

While ethanol is a renewable resource, its production from crops like corn and sugar cane raises ethical concerns around food security and land use. There can also be environmental impacts related to the agricultural practices used to grow these crops, such as pesticide use and deforestation. As such, it’s important to source ethanol from sustainable and ethical sources wherever possible.

In terms of environmental impact, hand sanitiser packaging, which is often single-use and made of plastic, can contribute to plastic pollution if not disposed of properly. Efforts should be made to use recyclable materials for packaging, or to set up systems for refilling containers.

Conclusion

Ethanol of 99.9% purity plays a crucial role in the production of hand sanitisers due to its effective germ-killing properties. By understanding the function of ethanol and how it’s incorporated into the final product, we can produce hand sanitisers that are both effective and safe. However, it’s also important to consider the ethical and environmental impacts of ethanol production and hand sanitiser packaging, and to take steps to mitigate these where possible.

References

Kramer, A., et al. (2002). Limited efficacy of alcohol-based hand gels. Lancet, 359(9316), 1489-1490.
Boyce, J.M., & Pittet, D. (2002). Guideline for Hand Hygiene in Health-Care Settings. Morbidity and Mortality Weekly Report, 51(RR-16), 1-44.
Gold, N.A., & Avva, U. (2020). Alcohol Sanitizer. In StatPearls. StatPearls Publishing.
Renewable Fuels Association. (2021). Ethanol Facts: Environment.
U.S. Food & Drug Administration. (2019). Q&A for Consumers: Hand Sanitizers and COVID-19.
Appendices
Appendix A: Recipe for DIY Hand Sanitiser

Note: This recipe is provided for informational purposes only. It is important to follow all local regulations and guidelines related to hand sanitiser production and use.

Materials Needed:

Ethanol (99.9% purity)
Glycerin (also known as glycerol)
Hydrogen Peroxide (3%)
Distilled or boiled water
Aloe Vera gel (optional, for skin conditioning)
Essential oil for fragrance (optional)
Clean measuring cups and spoons
A mixing container
An empty container for your finished product
Instructions:

Pour 833.3 ml of Ethanol into the mixing container.
Add 41.7 ml of Hydrogen Peroxide.
Add 14.5 ml of Glycerin.
If using, add 110.5 ml of Aloe Vera gel.
Add distilled or boiled water to make the total 1000 ml.
Mix well.
Pour the mixture into your empty container using a funnel, if necessary.
If desired, add a few drops of essential oil for fragrance.
Appendix B: Safe Handling and Storage of Ethanol

1. Always handle ethanol in a well-ventilated area away from heat sources, sparks, and open flames.
2. Wear appropriate personal protective equipment, such as safety glasses, gloves, and an apron.
3. Store ethanol in a well-ventilated, cool, and dry place.
4. Always keep ethanol containers tightly closed when not in use.
5. Follow local regulations for disposal of ethanol waste and empty containers.

 

Appendix C: Ethanol Suppliers

Labtech Chemicals – Windsor NSW
Always ensure that your supplier follows best practices for safety, quality, and sustainability.

Glossary

Ethanol: A volatile, flammable, colorless liquid with a slight characteristic odor. It is a psychoactive substance and is the principal type of alcohol found in alcoholic drinks.

Denaturing Proteins: The process of modifying the molecular structure of a protein, causing it to lose its natural function. In the context of ethanol as a disinfectant, this leads to the death of bacteria, viruses, and fungi.

Humectants: Substances that promote the retention of moisture.

Emollients: Substances that soften and soothe the skin.

Germicide: A substance that kills germs, especially pathogenic microorganisms.

Antiseptic: A substance that inhibits the growth and development of microorganisms. For practical purposes, antiseptics are routinely thought of as topical agents, for application to skin, mucous membranes, and inanimate objects, although a formal definition includes agents that are used internally, such as the urinary tract antiseptics.

Frequently Asked Questions

Q1: Can I use other types of alcohol for hand sanitiser production?
Yes, isopropanol (also known as isopropyl alcohol or rubbing alcohol) can also be used. However, the World Health Organization recommends ethanol due to its higher efficacy and lower toxicity.

Q2: Can I use lower purity ethanol for hand sanitiser production?
Using ethanol with a lower purity may result in a less effective product due to a lower concentration of alcohol. Moreover, impurities may have harmful effects or lead to unpleasant odors.

Q3: Can I add more ethanol to make my hand sanitiser more effective?
Hand sanitisers need to contain at least 60% alcohol to be effective. However, increasing the alcohol concentration beyond 95% may actually make the product less effective because water is needed for protein denaturation, which is how alcohol kills germs.

Q4: Can hand sanitisers replace handwashing?
Hand sanitisers can quickly reduce the number of germs on your hands in many situations, but they do not eliminate all types of germs and may not remove harmful chemicals like pesticides and heavy metals. Washing hands with soap and water for at least 20 seconds is the best way to clean your hands in most situations.

Additional Resources

WHO: Guide to Local Production: WHO-recommended Handrub Formulations – https://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf
CDC: Hand Hygiene Recommendations – https://www.cdc.gov/coronavirus/2019-ncov/hcp/hand-hygiene.html
FDA: Q&A for Consumers: Hand Sanitisers and COVID-19 – https://www.fda.gov/drugs/information-drug-class/qa-consumers-hand-sanitisers-and-covid-19
Acknowledgements

We thank all health workers and scientists who are working tirelessly to keep us safe. We also thank our readers for their interest in learning more about the science behind everyday products and hope that this guide has been informative and helpful.

About Us

We are a team of researchers and writers passionate about science, health, and hygiene. Our aim is to make complex scientific information accessible and understandable to everyone.

We welcome feedback and suggestions for improvement. If you have any questions or comments, please feel free to contact us.

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Revision and Update History

Version 1.0 – June 14, 2023 – Original publication.

Disclaimer

This guide is provided for informational purposes only and does not constitute medical or professional advice. It is based on the best available information at the time of writing, and while every effort has been made to ensure accuracy, changes in scientific knowledge and regulatory guidelines may affect the content. Always consult with a healthcare professional or relevant authority for advice in relation to hand sanitiser production and use.

Copyright

©2023. All rights reserved. No part of this booklet may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law.

Publisher Information

Pure Chemistry
Windor NSW , Australia
A Division of Precision Management