COVID-19 (initially called 2019-nCoV) has, since December 2019, spread to 127 countries and regions. While causing milder symptoms than SARS, and having a far lower mortality rate than either SARS or MERS, its infection rate appears far more accelerated.
Due to it being an enveloped virus (meaning its single-strand RNA is enveloped in a bubble of lipid or fatty molecules), COVID-19 (as all other coronaviruses) is highly susceptible to soap and disinfectants, which is good news. Some disinfectants are more effective than others, however, which is the focus of this article.
While there are many chemical disinfectants, focus on those that are most readily available for home use. You can learn more about other disinfectants and sterilizing agents used in health care settings on the CDC’s Chemical Disinfectants for Infection Control webpage.
Alcohol-based disinfectants will contain either ethyl alcohol or isopropyl alcohol at various levels of strength (50% or greater). While alcohol primarily kills bacteria, it also has potent fungicidal and viricidal activity at concentrations above 60%.
According to the U.S. Centers for Disease Control and Prevention, the microbial action of alcohol is thought to be due to its ability to denature proteins. Straight ethyl alcohol is less bactericidal than alcohol mixed with water, as the presence of water allows proteins to be denatured more rapidly.
When it comes to viruses, different alcohols are more or less effective depending on the type of virus in question.
If using an alcohol-based disinfectant to inactivate and protect against coronaviruses on surfaces around your home, make sure it contains between 60% and 80% alcohol. According to the World Health Organization:
“Alcohol solutions containing 60–80% alcohol are most effective, with higher concentrations being less potent. This paradox results from the fact that proteins are not denatured easily in the absence of water …”
Chlorine disinfectants such as household bleach, which typically contains 5.25% to 6.15% sodium hypochlorite, have broad antimicrobial activity and effectively kills bacteria, fungi and viruses, including influenza viruses. It has several major biological drawbacks, however.
Also make sure you dilute bleach with cold water, as hot water will inactivate it, rendering it ineffective for sterilization. Ideally, use mask and gloves when using bleach. You should also dilute it before using. “Infection Prevention and Control of Epidemic- and Pandemic-Prone Acute Respiratory Infections in Health Care” recommends diluting bleach containing 5% sodium hypochlorite to 0.05% before using.
Hydrogen peroxide has the ability to kill or inactivate bacteria, viruses, spores, yeast and fungi. A list of brand name sterilants and disinfectants cleared by the U.S. Food and Drug Administration that contain 1% to 7.5% hydrogen peroxide can be found on the FDA’s website.
Commercially available 3% hydrogen peroxide is stable and effective for disinfecting a wide variety of surfaces. Contrary to bleach, hydrogen peroxide is molecularly very similar to water — it just has an additional oxygen atom — so it doesn’t produce any dangerous compounds when breaking down. Its inherent safety (provided you don’t drink it) makes it an excellent choice for home sanitation.
An even better alternative is accelerated hydrogen peroxide (AHP), sold under the brand name Rescue and some others. Compared to pharmaceutical grade 3% hydrogen peroxide, AHP works much faster, so you don’t need to wet the surface for as long. AHP can kill viruses in as little as 30 seconds.
Another common household staple that can be used to disinfect viruses is 10% malt vinegar (made from malted barley grain, which is also used to make beer; a second fermentation turns the ale into vinegar
While 10% malt vinegar appears to be effective enough as a viral disinfectant, distilled white vinegar with an ascetic acid range of 4% to 8% is a rather poor choice, according to Talk CLEAN to Me, a blog by experts in chemical disinfection for infection prevention:29
“… the various organic acid disinfectants … typically lack a broad spectrum of kill compared to higher level disinfectants such as bleach and hydrogen peroxide … You may be thinking ‘Hey, wait! Vinegar and acetic acid have been used for hundreds of years as methods of disinfection and sanitization.’
However, it is important to note that these only show strength against relatively easy to kill organisms such as pseudomonas. There is no current data that concludes that organic acids bolster a broad spectrum of kill.”
In short, white vinegar has a low speed of disinfection (you’d have to leave it on for at least 10 minutes), and kills only the most easily destroyed microbes. That said, you could boost the effectiveness of white vinegar by using it in combination with hydrogen peroxide.