You already know you need to replace your toothbrush, smoke-detector batteries, kitchen sponges, sunscreen, and other common items on a regular schedule. I started thinking about all these disinfectants, sanitizers, masks, and gloves we've been using this past year. Let's review when to replace those products, especially as these kind of products do lose potency over time.
All disinfectants and sanitizers gradually lose potency, making them less effective at neutralizing COVID-19 or any viral disease.
First, do you know the difference between a "disinfectant" and a hand "sanitizer"? Let's review:
Sanitizing: Reducing, not killing, the number and growth of bacteria, viruses, and fungi. We should regularly sanitize food preparation areas, doorknobs, light switches, computer services, mobile phones, faucets, stair rails, and bed linens.
Disinfecting: Killing viruses and germs and microscopic organisms. Stopping the spread of infectious microbes. We don’t always need a disinfectant. Overusing disinfectant products can create resistant microbes. However, we DO need a disinfectant when there is someone ill in the house or someone has a compromised immune system.
Read more about which products actually kill viruses (and which do not).
Disinfectant products for households, designed to eliminate pathogens on contaminated surfaces, come in the form of liquids, sprays, and wipes. Instructions for use say to apply any disinfectant product until the treated surface is visibly wet, then allow it to dry for a certain amount of time, specified on the label, often called the “dwell time“—the amount of time a disinfectant must remain wet on a surface to properly disinfect it.
- Although experts tell us to “check the expiration date” on each bottle, spray can, or container of wipes, that can pose a challenge. With so many brands, so many different products, and so many ways/locations of posting a date, I can’t offer one sure way to find it on any given container.
- You’ll find many disinfectant containers, including chlorine bleach, stamped with a code specifying the precise day of a product’s manufacture. This allows you to determine the expiration date, once you know how long an unopened product will remain potent.
- Unopened, a bottle of chlorine bleach begins to lose its potency 6 months after its date of manufacture, and will become 20 percent less effective within a year.
- Check the bottle to find a stamped-on string of letters and numbers. If you see the code B5205507, B5 identifies the plant that manufactured this particular product; 20 represents the year of its manufacture (2020), and 55 presents the 55th day of 2020 (February 24). The final two numbers are simply another manufacturing identification code. Given that bleach expires after about 6 months, use basic math to determine that this bottle would have expired on August 24, 2020. (Calculate day numbers using a calendar like this.)
- Once the bottle is opened, the bleach deteriorates even faster. Exposure to light or to temperatures much above or below room temperature will further accelerate the process.
- To effectively neutralize Covid viruses, a bottle of liquid bleach should contain at least 6 percent sodium hypochlorite, the active disinfecting ingredient. I checked two bottles of unopened bleach in my laundry area and one in the bathroom, only to discover two of them contained only 3 percent sodium hypochlorite. I couldn’t find a code stamped anywhere on the third bottle. So while all this bleach will be okay for removing stains and eliminating mildew, it won’t disinfect virus-contaminated surfaces. Check the label and search for the code before you buy.
- If, like me, you use a 10 percent chlorine bleach solution (1 part bleach to 9 parts water) to disinfect cutting boards, door handles, and other hard surfaces, it will retain its potency for only 24 hours. You’ll need to make a fresh batch every day you use it. Using a very small spray bottle will help prevent waste.
- Don’t pour expired bleach down the drain or toilet if you’re on a home septic system, because the remaining sodium hypochlorite may cause environmental damage. Continue using the product for stain removal and simple household cleaning applications until it’s gone.
- Always apply and use disinfectants according to package directions. Remember, they are intended for disinfecting surfaces. Don’t use disinfectant liquids, sprays, and wipes on hands or other parts of the human body.
Remember: experts agree the best hand sanitizer is a vigorous, 20-second scrub with plain soap and water. Worth repeating: The best hand sanitizer is a vigorous, 20-second scrub with plain soap and water. However, if you're in the car or don't have soap and water available, hand sanitizers have a role.
- Use commercial hand sanitizers containing at least 60 percent ethanol when you don’t have soap and water available. Use the amount recommended on the bottle of sanitizer, and rub vigorously until it dries, or let it dry without wiping it off.
- The U.S. Food & Drug Administration (FDA) regulates hand sanitizers as over-the-counter (OTC) drugs. Approved OTC drugs, including hand sanitizer, will be effective, unopened and maintained at room temperature, for three years. There should be an expiration date listed on the container. (Remember that no OTC drugs, including hand sanitizers, have been proven to prevent Covid.)
- Don’t confuse antibacterial soaps and washes with hand sanitizer. Covid is a viral disease, not a bacterial disease, and antibacterial products will not neutralize virus particles. (FYI, the FDA hasn’t found antibacterial products any more effective at killing bacteria than plain soap and water, and they may hasten the spread of antibiotic-resistant bacteria.)
- To ease an earlier shortage of hand sanitizers, FDA issued guidelines that allowed some companies to manufacture hand sanitizers. Some of these products don’t not have an expiration date listed because the FDA expected them to be ordered and used quickly.
- And no, you can not make a reliably safe and effective sanitizer at home, and you can’t boost the potency of a commercial brand of sanitizer by adding isopropyl or ethyl alcohol to it.
Take the FDA 10-question quiz to test your knowledge about hand sanitizers. Each answer links to a web source that further explains the answer.
* Disinfecting and sanitizing products aren’t like perishable foods that “go bad” after their expiration dates. Sanitizers and disinfectants may lose some or all of their disinfecting potency, but using them as directed after their expiration date won’t harm surfaces or your hands.
Can you reuse a face mask? The quick answer is maybe, depending on the type of mask, whether you’ve put it on, worn it, and taken it off correctly, where you’ve been while wearing it, and where you store it after use. Infectious disease experts say:
- Rule number one for any type of face mask: Don’t touch the mask anywhere except for its ear loops or other straps. Invisible virus particles attached to the mask’s outer or interior surface may transfer to your hands, and from your hands to other surfaces, to people in your household, your clothes, your face, or your hair.
- Wash your hands both before putting on and after removing a face mask, just to be sure.
- Don’t reuse any face mask that’s visibly dirty, stained, torn, or stretched beyond its original shape.
- Fabric masks can be sanitized simply by washing them after removing the carbon filter, if you’ve used one between the layers of fabric.
- To store a disposable N95 or paper mask for reuse, drop it into a clean paper bag and quarantine it there for at least a day. Keep a few extra masks on hand to rotate with the quarantined masks. Don’t share bags with other members of your household.
- Public health experts suggest wearing gloves to protect against coronavirus only when you’re disinfecting high-touch surfaces that might be contaminated. Don’t wash or reuse the gloves, but toss them immediately into a covered trash container. Then wash your hands.
- When you’re out shopping, public health experts say to forget the gloves and just keep your hands bare, and wash or use hand sanitizer immediately afterward you’ve completed your tasks. For one thing, it’s difficult to remove possibly contaminated, thin, disposable gloves without contaminating yourself.
- Experts would rather see people practice "good hand hygiene." Wash your hands before you get to the store, when you leave the store, and after you unload your purchases at home.
- If you're going to use the glove to pump gas, here's the rule: One Task. Only. Do it. Then PITCH the glove. Otherwise, you're going to contaminate yourself later with whatever you touched with gloves on in the store.
- Washing surgical gloves with sanitizer or soap and water may create microscopic tears that could also let virus particles through.
Cleaning And Disinfecting Your Home: Everyday Steps and Extra Steps When Someone Is Sick
Q&A for Consumers | Hand Sanitizers and COVID-19
Reviewed and edited for medical accuracy by infectious disease expert Dr. Judy Stone