Alcohol-Based Hand Sanitisers: What They Do Well, Where They Fail, and How to Use Them Safely

Alcohol-based hand sanitisers are now part of everyday life. They sit at shop entrances, in cars, classrooms, and pockets. During the COVID-19 pandemic, they became a symbol of protection.

But convenience has created confusion. Many people believe hand sanitiser kills all germs instantly, replaces handwashing, and is harmless no matter how often it is used. None of these beliefs is fully true.

This article explains how alcohol-based hand sanitisers actually work, when they are useful, when they are not, and what risks come with misuse.

What Is an Alcohol-Based Hand Sanitiser?

Alcohol-based hand sanitisers are liquids, gels, or foams designed to reduce microorganisms on the hands without using water.

Their key feature is alcohol. Most effective products contain:

  • Ethanol

  • Isopropyl alcohol

  • Or a combination of both

For a sanitiser to work properly, the alcohol concentration must usually fall between 60% and 95% by volume. Below this range, germs survive. Above it, effectiveness can paradoxically drop because alcohol needs some water to work properly on microbial proteins.

How Alcohol Kills Germs

Alcohol kills germs by damaging their proteins and cell membranes. This causes bacteria and many viruses to lose their structure and stop functioning.

Alcohol-based sanitisers are very effective against:

  • Many common bacteria

  • Respiratory viruses

  • Enveloped viruses, including coronaviruses and influenza

They are less effective or ineffective against:

  • Bacterial spores

  • Some non-enveloped viruses

  • Certain parasites

This matters because it explains why sanitiser is helpful—but not universal.

Why Hand Sanitiser Does Not Work Instantly

One of the most common misconceptions is that hand sanitiser kills germs the moment it touches the skin.

In reality:

  • It requires time and friction

  • Hands must be rubbed for 20–30 seconds

  • All hand surfaces must be covered

Using a small drop, spreading it briefly, or wiping it off early dramatically reduces its effectiveness.

Proper Use: What Most People Get Wrong

Correct use makes a major difference.

To use alcohol-based hand sanitiser properly:

  1. Apply enough product to wet the entire surface of both hands

  2. Rub palms, backs of hands, between fingers, thumbs, and fingertips

  3. Continue rubbing until hands are completely dry

  4. Do not wipe or rinse

Quick, half-hearted application offers only partial protection.

When Hand Sanitiser Is the Wrong Choice

Hand sanitiser is not a replacement for handwashing in all situations.

Soap and water are better when:

  • Hands are visibly dirty or greasy

  • Hands are contaminated with bodily fluids

  • There is a possible exposure to spore-forming bacteria

  • After using the toilet

  • Before preparing food

Sanitiser works best on clean-looking hands when washing is not immediately available.

Skin Problems and Overuse

Frequent use of alcohol-based sanitisers strips the skin of natural oils. Over time, this can lead to:

  • Dryness

  • Cracking

  • Irritation

  • Contact dermatitis

Many products contain moisturisers such as glycerin or aloe, but these do not fully prevent skin damage with repeated use. Broken skin also increases infection risk.

Toxicity and Safety Risks

Alcohol-based sanitisers are safe when used correctly, but they are not harmless.

Potential risks include:

  • Accidental ingestion, especially in children

  • Alcohol poisoning from swallowing sanitiser

  • Toxic contamination in poorly regulated products

  • Fire risk, as alcohol is highly flammable

During health emergencies, substandard or illegally manufactured products may enter the market. This makes regulation and consumer awareness critical.

Hand Sanitisers in Healthcare Settings

In hospitals and clinics, alcohol-based hand rubs are considered the standard method for routine hand hygiene when hands are not visibly soiled.

They improve compliance because they are:

  • Faster than handwashing

  • Easier to access

  • Less irritating than frequent soap use

Better compliance is strongly linked to lower rates of healthcare-associated infections. However, compliance remains far from ideal, which is why education and system-wide strategies matter more than the product alone.

Myths That Still Need Correcting

Several beliefs persist despite strong evidence:

  • Hand sanitiser does not kill all germs

  • More alcohol does not mean better protection

  • Sanitiser does not replace soap and water

  • Overuse can increase skin damage and infection risk

Understanding these limits improves safety rather than reducing protection.

The Take-Home Message

Alcohol-based hand sanitisers are powerful tools when used properly. They reduce the transmission of many infectious organisms and play an important role in public health.

But they are not magic.

Good hand hygiene depends on:

  • Using the right product

  • Applying it correctly

  • Knowing when to wash instead

  • Avoiding overuse and misuse

When people understand these basics, hand sanitiser becomes what it was always meant to be—a helpful aid, not a false sense of security.

References:

Saha T, Khadka P, Das SC. Alcohol-based hand sanitizer – composition, proper use and precautions. Germs. 2021 Sep 29;11(3):408-417. doi: 10.18683/germs.2021.1278. PMID: 34722363; PMCID: PMC8548033.

Gold NA, Mirza TM, Avva U. Alcohol Sanitizer. 2023 Aug 9. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan–. PMID: 30020626.

Jing JLJ, Pei Yi T, Bose RJC, McCarthy JR, Tharmalingam N, Madheswaran T. Hand Sanitizers: A Review on Formulation Aspects, Adverse Effects, and Regulations. Int J Environ Res Public Health. 2020 May 11;17(9):3326. doi: 10.3390/ijerph17093326. PMID: 32403261; PMCID: PMC7246736.

Stadler RN, Tschudin-Sutter S. What is new with hand hygiene? Curr Opin Infect Dis. 2020 Aug;33(4):327-332. doi: 10.1097/QCO.0000000000000654. PMID: 32657970.