9 dos and don’ts of disinfecting

Keeping your home, office, and other public spaces clean has become even more of a priority since the COVID pandemic. But using powerful cleaning chemicals improperly can do more harm than good. It’s important to learn the best and safest ways to use them—and how often.

Do we really need to clean so much?

It’s normal to keep our spaces clean if we’re concerned about spreading viruses or bacteria, but do we need to scour our entire home?

Every single surface doesn’t need to be disinfected, notes Elizabeth Scott, PhD, Professor Emerita of Simmons University and home and community hygiene and infection control consultant in Boston.

Instead, Scott recommends an approach called “targeted hygiene,” which entails focusing on areas that are most involved in the transmission of disease. In layperson’s terms, that means addressing common-touch surfaces such as:

• Counters and tabletops
• Appliance surfaces
• Doorknobs
• Light switches
• Bathroom fixtures and toilets
• Phones and tablets
• Computer keyboards
• Remote controls
• Bedside tables

And if any other surfaces become visibly dirty, disinfect them, too, just to be safe.

Cleaning vs. disinfecting

Before you bring out the disinfectants, the first step is to clean the area in question. Cleaning means using soap and water to remove debris and dirt from surfaces. While taking this step does not kill germs, it can help lower their numbers and the risk of them spreading. Plus, a buildup of dirt can reduce the effectiveness of disinfectants.

Disinfecting comes next and involves using products to kill germs. This process does not necessarily remove grime from surfaces (which makes the first step important), but when you kill germs on a surface after cleaning, you lower the risk of spreading infection even more.

“All told, disinfection implies cleaning followed by the use of a chemical that reduces or eliminates bacteria and viruses,” says Scott. Bleach, ammonia, hydrogen peroxide and 70 percent rubbing alcohol are disinfectants that can be used safely at home, as long as you follow these guidelines:

Do consider the type of surface—and rinse after cleaning

Depending on the surface you’re disinfecting, it’s often a good idea to rinse with water afterwards. For example, bleach and peroxide can discolor or damage certain types of countertops if the chemicals are left to stand on them. Because bleach can corrode metal, it’s also advisable to use other products on faucets and stainless steel.

Do follow directions on cleaners and disinfectants

Daniel E. Brooks, MD, Research Medical Director of Banner Poison and Drug Information Center in Phoenix says that products’ directions are comprehensive and can help you use them safely and effectively. Unsure of how to handle electronics? Wipes or sprays containing at least 70 percent alcohol can disinfect screens. Just remember to dry your gadgets thoroughly so liquids don’t remain on them.

Do take steps for cleaner air

Some germs, including flu viruses and the virus that causes COVID, can spread through the air, especially in indoor spaces with poor ventilation. Keep windows open when possible and use exhaust fans. If you have a central heating, ventilation, and air conditioning system (HVAC) with a filter, it can help to keep the filter fresh and set the fan to “on.” You can also use a small high-efficiency particulate air (HEPA) cleaner.

Try out the Centers for Disease Control and Prevention’s (CDC) Interactive Home Ventilation Tool online to look at the difference you can make when you make a few fresh-air changes.

Don’t use disinfectants in close spaces, like closets

Exposure to cleaning product fumes can contribute to respiratory distress. To prevent this, make sure there is a good amount of ventilation where you’re cleaning. If there isn’t a window that can be opened, consider running a fan to promote air movement.

Do wear rubber gloves

They help protect your skin from harsh chemicals. Wash your hands with soap and water for 20 seconds after you take the gloves off.

Don’t disinfect foods

“Even before COVID, people were cleaning food or fruits with stuff like hydrogen peroxide, and all of that is completely unnecessary. There's no science behind it,” Dr. Brooks says. “It’s potentially harmful. Cleaning fruits and vegetables and foods with hydrogen peroxide does not promote health.”

That said, if you have a wooden or plastic cutting board that can’t be placed in the dishwasher, you can disinfect it with a solution of one tablespoon of unscented chlorine bleach per gallon of water (more on mixing ratios below). Saturate the surface with the solution, let it stand for several minutes, rinse thoroughly with water, then air dry or dab with paper towels.

Don’t use vinegar solutions to disinfect

“There is plenty of evidence that so-called home remedies such as vinegar and water are not effective at disinfecting inanimate surfaces,” Scott says. “Using them can leave people with a false sense of security.” Although some research suggests that vinegar cleans surfaces and helps kill some bacteria, it doesn’t do so as effectively as commercial cleaners, and it does not work with viruses, including the virus that causes COVID.

So, if you’re cleaning things like mirrors, break out the vinegar solution. But, Scott notes, “to safely and effectively disinfect an area such as a food prep surface or a common-touch surface, the recommendation is to use the appropriate dilution of household bleach or other disinfectant such as Lysol, following the label recommendations.”

Don’t mix chemicals

Avoid mixing any cleaning chemicals or disinfectants with anything besides water. “Combining chemicals poses a risk of unknown synergistic effects,” Brooks says. In other words: “You could actually start a chemical reaction that generates heat or gas, which could lead to eye injury or pulmonary or lung injury.”

Some common chemicals you should never mix include:

• Ammonia (often found in glass cleaner and some paints) and bleach
• Bleach and any acid (including vinegar; any lime, calcium or rust removal products; glass or toilet or drain cleaners; and dishwashing detergents)
• Bleach and rubbing alcohol
• Hydrogen peroxide and vinegar
• Hydrogen peroxide and bleach

Do dilute concentrated products with water

“The safest way to do it is to add the cleaning agent into water,” Brooks says. Many product labels explain the product-to-water ratio to use, but for a basic bleach disinfecting solution, mix five tablespoons (or 1/3 cup) of bleach for each gallon of water, or use four teaspoons of bleach per quart of water. Just remember to use your solution within 24 hours. The bleach will fade in strength and can cause certain plastic containers to deteriorate in the meantime.

Do use common sense

“You can prevent injuries and exposures just by using your head,” Brooks says. Needless to say, only use household cleaners and disinfectants on surfaces in your environment, and never eat, drink or inject them. And always keep chemicals away from children.

If you have any questions about the safety, use, or handling of any chemicals, don’t take a chance—call Poison Control at 1-800-222-1222 for more information.