Published 15 April 2020
Coronavirus has chinks in its armour that make it susceptible to a variety of cleaning products. Which ones are the most effective, and how do they stop the contagion from spreading?
Although there is a lack of evidence about the effectiveness of cleaning products against the novel 2019 coronavirus, several antimicrobial agents have been tested against other coronaviruses and have proven to be the most effective cleaning products at rendering viruses inactive.
As we have all come to know by now, the first line of defence against the causative infectious agent involved in the current outbreak is soap and water. Currently, there are no drugs that can kill the virus that causes COVID-19 but wash your hands for 20 seconds, and you’ll stop it from spreading. So what makes soap a good coronavirus killer?
First, the mechanical action of washing wipes germs off the surface of your hands and sends them down the drain. Secondly, soap dissolves the virus’s lipid layer and interferes with the weak chemical bonds holding the virus together. With its structural integrity breached, the virus disintegrates.
Bleach is a powerful and effective disinfectant because of its active ingredient, called sodium hypochlorite, which kills viruses, including influenza. It does this by destroying the protein coat that covers the virus and its RNA (ribonucleic acid). This is the genetic material that ‘reprogrammes’ host cells turning them into virus-making factories.
According to the European Centre for Disease Prevention and Control (ECDC), tests involving SARS-CoV demonstrated that 0.1% sodium hypochlorite inactivated the virus within one minute.
The Centres for Disease Control and Prevention (CDC) in the United States recommends a diluted bleach solution by mixing:
Alcohol (which can be found in hand sanitisers, surgical spirit and some hand wipes) is effective because it causes the protein coat of the virus to unravel and change its shape. This is a process known as denaturation, and it stops the virus from functioning as normal. A 2011 study (Inactivation of surrogate coronaviruses on hard surfaces by healthcare germicides) in the American Journal of Infection Control found that healthcare germicides with 70% concentration ethanol had a stronger effect on two coronaviruses (mouse hepatitis virus and transmissible gastroenteritis virus) after one minute contact time on hard surfaces than 0.06% sodium hypochlorite.
Surgical spirit is primarily made up of ethanol, which at concentrations of between 62% and 71% can reduce coronavirus infectivity within one minute, according to a recent paper (Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents) in the Journal of Hospital Infection.
Hydrogen peroxide is another good disinfectant, and it works by producing chemicals known as free radicals that attack membrane lipids and other essential cell components. According to the CDC, 3% hydrogen peroxide can inactivate rhinovirus, the leading cause of the common cold.
We are living in uncertain and unsettling times, but at least we have a few weapons at our disposal to make our environments safer.