There are two types of disinfection supplies that are commonly used for disinfection: 1) disinfectants and 2) hand sanitizes. Disinfectants are antimicrobial agents designed to inactivate or destroy microorganisms on inert surfaces. Disinfectants are frequently used in hospitals, dental surgeries, kitchens, and bathrooms to kill infectious organisms.
Along with the outbreak of infectious diseases such as COVID-19, many people have started using disinfectants in households as well.
Hand sanitizes can be also viewed as a type of disinfectants, but they are used exclusively for hand hygiene. Many health-related organizations, including the U.S. Centers for Disease Control and Prevention (CDC), have explained the advantages and limitations of disinfectants and hand sanitizes. They are summarized Table 1 and the details are delineated below.
Table 1. Advantages and limitations of disinfectants and hand sanitizers
CDC has suggested a list of recommendations to fight against COVID-19, and using disinfectants is one of them. In particular, CDC recommends to clean and disinfect frequently touched surfaces and objects such as tables, countertops, light switches, doorknobs, and cabinet handles.
Although the spread and transmission of viruses happen most frequently from person-to-person via respiratory droplets, current evidence suggests that COVID-19 may remain viable for hours to days on surfaces made from a variety of materials.
Therefore, at least theoretically, COVID-19 can be transferred from any infected person to surfaces, and then from the surfaces to another person. As such, disinfecting visibly dirty surfaces is recommended for the prevention of COVID-19 and other viral respiratory illnesses in households and community settings. For these reasons, the Environmental Protection Agency (EPA) has recently released a list of registered disinfectant products that have been qualified for use against SARS-CoV-2, the novel coronavirus that causes COVID-19.
Hand sanitizers have a long history since 1966 when a student nurse patented the idea of an alcohol-based gel to clean hands in the absence of handwashing facilities. However, it was not until the swine flu pandemic in 2009 that the product went from being used in institutions to the wide usage by the public. Similarly, the demand for hand sanitizers skyrocketed along with the outbreak of COVID-19.
As almost everyone is aware of these days, washing with warm water and soap is the gold standard for hand hygiene and preventing the spread of COVID-19. Washing with warm water and soap removes oils from our hands that can harbor microbes. However, hand sanitizers can also protect against disease-causing microbes, especially in situations when soap and water are not available. Hand sanitizers are proven to be effective in reducing the number and type of microbes. For these reasons, CDC and other health-related organizations recommend using hand sanitizers when soap and water are not accessible.
In general, there are two types of hand sanitizers: alcohol-based and alcohol-free hand sanitizers. Alcohol-based hand sanitizers contain varying amounts and types of alcohol, often between 60% and 95% and usually isopropyl alcohol, ethanol or n-propanol. Only alcohol-based hand sanitizers are known to be able to kill most germs.
Alcohol-free hand sanitizers contain quarternary ammonium compounds (e.g., benzalkonium chloride) instead of alcohol, which can reduce microbes but are less effective than alcohol. Alcohol-based hand sanitizers are effective not only at killing bacteria but also against viruses. In particular, alcohol attacks and destroys the envelope protein that surrounds some viruses, including the virus that causes COVID-19 (SARS-CoV-2). Since this envelope protein is vital for a virus’s survival and multiplication, alcohol-based hand sanitizers can eliminate the virus by destroying the envelope protein.
However, not all alcohol-based hand sanitizers are effective at killing viruses. CDC recommends the use of alcohol-based hand sanitizers with greater than 60% ethanol or 70% isopropanol in order to kill most viruses. Hand sanitizers with less than 60% ethanol or 70% isopropanol are less effective at killing bacteria and fungi and may only reduce the growth of germs rather than killing them.