How to prepare Hand Sanitizers?

        The whole world is currently engaged in the battle against COVID-19 pandemic. Masks, soaps and hand sanitizers are playing a very crucial role in this war against this deadly CORONA virus which has already claimed the lives of over 3 lakh people. In this scenario my first post has to be on the preparation of hand sanitizers. Hand sanitizers come in various forms - as gels, as liquids, as foams, etc. Have you ever thought how hand sanitizers are prepared? I am sure you have. This post will give you the technical know-how on the preparation of hand sanitizers.

    Hand Sanitizers are mostly based on alcohol. It can be either ethanol or isopopyl alcohol (also called isopropanol). The following formulation is for the preparation of hand sanitizer based on isopropanol (as it is more easily available than ethanol) according to WHO guidelines. WHO recommends at least 75 % alcohol for the preparation of effective hand sanitizers.

The WHO formulation for preparing 10 L of  hand sanitizer is

7515 mL of isopropanol (99.8 %)

 417  mL of hydrogen peroxide (3 % )

 145  mL glycerol (98%)

 123  mL distilled water (boiled and cooled water can also be used) 

The alcohol is the main ingredient in the hand sanitizer which plays the role of the disinfectant. Hydrogen peroxide is added to kill bacteria that might have entered the storage bottles during the process of preparation. Glycerol is the emollient which softens and moisturizes the skin and protects it from the drying effect of the alcohol and hydrogen peroxide. The concentration of hydrogen peroxide we get might not necessarily be 3 %. Here we get 30 % hydrogen peroxide, so we have to accordingly reduce the amount of peroxide (as it is more concentrated) and dilute it with distilled water.

The following useful link gives a guide to local production of WHO-recommended Handrub formulation. It gives elaborate procedures with pictures for the preparation of hand sanitizers:

https://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf

Test on Hand Sanitizers

As part of the course E-teaching with AKPCTA we had received an assignment to create an online assessment question link in our blog. So here is a link for assessment of your knowledge on hand sanitizers. Enjoy...

https://forms.gle/1beeM7ewvn8z4Ett8

    When the COVID -19 pandemic reached Kerala, the Department of Chemistry at Bishop Moore College jumped right into the Break The Chain campaign initiated by the Government of Kerala by providing hand sanitizers to everyone entering the campus. We inquired with the General Hospital in Mavelikara if they needed hand sanitizers and they were more than happy to hear this proposal. They forwarded to us the above WHO guidelines for the preparation of hand sanitizers and within a week we had prepared more than 40 L of hand sanitizer and distributed it to hospitals, police station and educational institutions in the neighborhood.