“Not many scientific studies have asked which are the most effective disinfecting agents to use against SARS-CoV-2, the virus that causes COVID-19, because it was discovered so recently,” says Siobain Duffy, associate professor of ecology at Rutgers University with expertise in emerging viruses and microbial evolution. “So scientists are assuming that what works against other coronaviruses can work against this one.”
“Each disinfecting chemical has its own specific instructions. But an important general rule is that you shouldn’t immediately wipe a cleaning solution off as soon as you’ve applied it to a surface. Let it sit there long enough to kill viruses first,” says Donald Schaffner, professor and extension specialist in food science with expertise in microbial risk assessment and handwashing.
The US Centers for Disease Control and Prevention recommends daily disinfection for frequently touched surfaces such as tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks.
If someone in your home is sick with flu-like symptoms, consider regularly disinfecting objects in your home, since SARS-CoV-2 has been shown to survive for 16 hours on plastics.
Whatever cleaning solution you use, let it remain in contact with the surface long enough to kill viruses and other pathogens. The time needed will depend on the chemical.
Don’t use different cleaning agents at the same time. Some household chemicals, if mixed, can create dangerous and poisonous gases.
Bleach can be diluted with cold water to make an effective disinfectant against bacteria, fungi, and many viruses including coronaviruses. You can typically use one-quarter cup of bleach per 1 gallon of cold water—but be sure to follow the directions on the label of your bleach.
You can dilute alcohol with water (or aloe vera to make hand sanitizer) but be sure to keep an alcohol concentration of around 70% to kill coronaviruses. Many hand sanitizers have a concentration of about 60% alcohol, and Lysol contains about 80%; these are all effective against coronaviruses.
Solutions of 70% alcohol should be left on surfaces for 30 seconds (including cellphones—but check the advice of the phone manufacturer to make sure you don’t void the warranty) to ensure they will kill viruses. Pure (100%) alcohol evaporates too quickly for this purpose.
A 70% alcohol solution with water will be very harsh on your hands and should not be used as a substitute for handwashing and/or hand sanitizer.
Hydrogen peroxide is typically sold in concentrations of about 3%. It can be used as is, or diluted to 0.5% concentration for effective use against coronaviruses on surfaces. It should be left on surfaces for one minute before wiping.
A study on influenza virus found that cleaning with a 10% solution of malt vinegar was effective, but few other studies have found vinegar to be able to kill a significant fraction of viruses or other microbes.