Medtrix

What are hand sanitizers?

Hand rub or hand sanitizers (as commonly called), are formulations used to inactivate or destroy infectious agents on hands. They are of two types, depending on the active ingredient used:

• Alcohol based and
• Alcohol free

For the purpose of this article, we would focus on the alcohol-based hand sanitizers.

The alcohol-based formulations are the most effective and should serve as an alternative when, hand washing with soap and water cannot be done. Not all hand santizers come in gel form, some come as liquids while others could be foam-like. So, don’t think that a gel-like hand sanitizer is more effective than either a liquid or a foamy hand sanitizer because they all possess equal effectiveness.

Active agent

The active component is alcohol (which could be ethanol, isopropanol or n-propanol). Sanitizers that contain 60% to 95% alcohol are most effective, so look out for this whenever you purchase hand sanitizers especially at this period where anyone can choose to make and sell hand sanitizers.

How it works

At concentrations of 60-95%, alcohol would actively denature (unfold and inactivate) proteins. This makes hand sanitizers very effective in neutralizing certain types of microorganisms but not their spores (reproductive structures that organisms use for dispersal, and survival in unfavourable environments). Higher concentrations of alcohol are less potent because proteins are not denatured easily in the absence of water.

Alcohol-based sanitizers can kill many kinds of bacteria. 90% alcohol rubs kill many kinds of viruses, including the flu virus, the common cold virus, coronaviruses, and HIV, but it should be noted that sanitizers are ineffective against the rabies virus.

What you need to know

1. Hand sanitizers should not replace handwashing with soap and water when it is available.

Washing hands with soap and water whenever possible is recommended by CDC. Although hand sanitizers can quickly reduce the number of microbes on hands in some situations, they do not eliminate all types of germs.

Soap and water are more effective than hand sanitizers at removing certain kinds of germs, like Cryptosporidium, norovirus ( a very contagious virus that causes vomiting and diarrhoea), and Clostridium difficile.

2. They must be used in the right volume and procedure.

When used correctly, alcohol-based hand sanitizers can inactivate many types of microbes very effectively. Use a large enough volume of the sanitizers and do not wipe it off before it has dried.

3. They may not be effective when hands are visibly dirty or greasy.

Hands may become very greasy or soiled after people handle food, play sports, work in the garden or in health care settings. When hands are heavily soiled or greasy, handwashing with soap and water is recommended because hand sanitizers may not work well in such circumstances.

4. Consumable alcohol cannot serve as hand sanitizer.

Although alcoholic drinks contain ethanol, the concentrations are usually between 5%-40%, though some are higher. Hand sanitizers without 60-95% alcohol may not work properly for many types of germs and would merely reduce the growth of the germs rather than kill them outright.

5. They are not effective in removing harmful chemicals, like pesticides and heavy metals, from hands.

Hand sanitizers may be ineffective in removing or inactivating many types of harmful chemicals. If hands have touched harmful chemicals, wash thoroughly with soap and water.

You can now do it the right way

In summary, the effectiveness of hand sanitizers depend on multiple factors, including quantity used, duration of exposure, frequency of use, and whether the specific infectious agent present on the person’s hands would be susceptible to the active ingredient in the hand sanitizer.

When using hand sanitizers, apply the product to the palm of one hand (2.4 to 3 mL is recommended) and and rub thoroughly over fingers and hand surfaces for a period of 25-30 seconds (application time required to achieve hand disinfection), followed by complete air-drying. This simple procedure effectively reduces populations of bacteria, fungi, and some enveloped viruses.

Most hand sanitizers, as said before, are relatively ineffective against bacterial spores, non-enveloped viruses, and encysted parasites. Thus, it becomes important to repeat that hand sanitizers should not replace proper handwashing where handwashing materials are available.

Maureen.