What is the perfect sanitiser for you?

Pushpa Girimaji

We are all told that we need to use hand sanitisers as a protection against the spread of Coronavirus. However, there are so many sanitisers in the market that I am totally confused.

Which santiser should I choose or what do I look for in a sanitiser?

The active ingredient in a hand sanitiser is alcohol, which is a known broad-spectrum antimicrobial. There are also some non-alcohol based sanitisers, but for coronavirus, experts recommend only alcohol-based sanitisers. The alcohol used could be either ethyl (ethanol) or isopropyl (Isopropanol) or n. propanol or a combination of two of these alcohols.

So first and foremost, one should look at the content of the hand sanitizer, and then buy the one which has alcohol as its main active ingredient. Such sanitisers will also have minute quantities of emollients and maybe some fragrance too.

Which is effective in killing coronavirus: an ethanol-based sanitiser or propanal-based?

Some studies had earlier suggested that ethanols could be more effective or have a stronger and broader virucidal activity compared to proponals. However, in a more recent study comparing the virucidal activity of the formulations based on ethanol and isopropanol, the World Health Organisation found the latter to have a higher virucidal activity against enveloped viruses. The two formulations were tested against Zika virus, Ebola virus, severe acute respiratory syndrome coronavirus (SARS-CoV), and Middle East respiratory syndrome coronavirus (MERS-CoV).

“In conclusion, WHO-recommended alcohol-based formulations were validated with different enveloped viruses. A strong virucidal effect against emerging pathogens, including ZIKV, EBOV, SARS-CoV, and MERS-CoV, could be demonstrated, implicating the usability of these WHO formulations in healthcare and outbreak-associated viral infections,” the study concluded. Thus, one can buy sanitisers with either of the alcohols, or the one having a combination of both.

What should be the percentage of alcohol in sanitisers?

The WHO formulation for use in health care suggests 80 per cent ethyl alcohol or 75 per cent iosopropyl alcohol. According to the Centres for Disease Control and Prevention, USA, studies have shown that sanitisers with an alcohol concentration of 60-95 per cent are more effective than those with lower alcohol concentration or non-alcohol based sanitisers. It, therefore, recommends a minimum of 60 per cent alcohol in the sanitiser for it to be useful. A review of various studies on the efficacy of ethanol against viruses in hand disinfection (The Journal of Hospital Infection, Kampf G, 2017) said 95 per cent ethanol covers the majority of clinically relevant viruses. However, “the selection of a suitable virucidal hand rub should be based on the viruses most prevalent in a unit and on the user acceptability of the product under frequent-use conditions”, the review concluded.

Another study on “Virucidal activity of 70 per cent ethanol vs Enveloped and non-enveloped viruses” (NR Clyde, Institute for Antiviral Research, Utah state university) found that enveloped viruses were extremely vulnerable to 70 per cent of ethanol. Coronavirus is an ‘enveloped’ virus. In fact most virologists and pathologists recommend sanitisers with 70 per cent alcohol for killing Coronavirus.

Viruses, which come in many shapes and sizes, are enclosed in a protein coat called capsid. In some viruses, capsid is surrounded by an envelope composed of a lipid bylayer — the latter are called enveloped viruses. Alcohol destroys them by denaturing their proteins and dissolving the lipids.

Consumers must remember that the effectiveness of a sanitiser also depends on its correct usage. One must use adequate quantity, 2-3 ml, depending on the hand size. Pour it on the palm and rub it with both hands, just the way you do with soap, till the hands are dry. The entire process should take about 20-30 seconds, according to WHO. It is also important to check whether the bottle of a sanitiser is properly closed. I have often seen bottles with poor closures that allow leakage of the product within. In fact, the containers and the lids should be so designed as to prevent leakage and also evaporation.

Having said that, it is best to wash hands with soap and water. The sanitiser should be used only when water is not available and for sanitising things like cell phones, handbags, etc. Sanitisers work well when hands are not heavily soiled or greasy.

What should one do if chemists do not sell sanitisers at the government-mandated price?

Complain to the local legal metrology department, consumer affairs department as well as the drug control department. If you have no other option but to buy it, take a receipt and send a complaint along with a copy of the receipt, seeking a refund of the excess amount charged and suitable action against the chemist/retailer. Sanitisers are now essential commodities under the Essential Commodities Act and the government has put a cap on the price of sanitisers at 50 paise for an ml of the liquid.

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