Whether you’re concerned about cold and flu season or the recent epidemic of coronavirus disease 2019 (COVID-19), you’ve probably heard that washing your hands is the most effective way to protect against germs. If soap and water aren’t available, hand sanitizer is the next best thing to keep your family safe and healthy. But is that old Purell rattling around underneath the bathroom sink still potent enough for an on-the-go clean-up? Or should you stick to brand-new bottles?
Does hand sanitizer expire?
The short answer is: Yes, hand sanitizer does expire. You should find an expiration date on the label or listed on the bottom of the container. As an over-the-counter topical antiseptic product, hand sanitizer is regulated by the U.S. Food and Drug Administration (FDA), and is required to either have a printed expiration date or have a shelf life of three years. That means if you can’t find an expiration date on your bottle of hand sanitizer, you should assume it will expire about three years after you purchased it.
What causes hand sanitizer to expire? Over time, alcohol evaporates from hand sanitizer products, reducing the potency, explains Robert Williams, MD, a family medicine doctor and geriatrician in Lakewood, Colorado, and a medical advisor for eMediHealth.
“It is considered expired when the amount of the sanitizer’s antibacterial agent decreases below 95% of its stated level,” says Dr. Williams.
Hand sanitizers typically fall into two categories: alcohol and non-alcohol based. The FDA currently allows marketing of ethyl alcohol (most common) and isopropyl alcohol as alcohol-based sanitizers, and benzalkonium chloride as a non-alcohol based sanitizer. Sanitizers with an alcohol concentration between 60% and 95% are considered the most effective. But all that alcohol can dry out your hands with repeated use (so don’t forget to moisturize!). Non-alcohol-based sanitizers typically contain benzalkonium chloride as their active ingredient. These types of hand sanitizers are often gentler on the skin, but they are not considered as effective as alcohol-based sanitizers.
Does expired hand sanitizer still work?
Hand sanitizer, though less potent after its expiration date, will still kill some germs. “It’s completely safe to use even after its expiration date but won’t be as effective in eliminating germs as a fresh batch,” says Dr. Williams.
“If you use enough of it to scrub your hands, it’ll reduce the number of microorganisms on them,” he says. “But it’s always best to wash your hands with soap and water.”
When you’re ready to throw away your old or expired bottle of hand sanitizer to buy a new one, make sure you’re doing it safely, says Kristi C. Torres, Pharm.D., a member of the SingleCare Medical Review Board from Austin, Texas.
“Alcohol-based hand sanitizers are actually flammable liquids at room temperature,” she explains. “If disposing in a home setting, follow your jurisdiction’s policies for disposing of flammable fluids.”
Hand sanitizer vs. hand-washing
In the fight against illnesses, hand-washing should always be your first line of defense, says Dr. Williams. These illnesses may include stomach bugs and parasites like Clostridium difficile, cryptosporidium, and norovirus. Fun fact: October 15 is Global Handwashing Day!
“Washing your hands with soap and water is always the go-to solution for reducing the amount of germs on hands,” he says. The Centers for Disease Control and Prevention (CDC) agrees and recommends a five-step approach to proper hand-washing:
- Use clean running water (it can be warm or cold) to wet your hands before soaping up.
- Lather, including the back of your hands, under your nails, and between your fingers.
- Scrub for at least 20 seconds, or the equivalent of singing the “Happy Birthday” song two times.
- Rinse your hands.
- Dry your hands on a clean towel or let them air dry.
If you aren’t able to wash your hands, that’s when hand sanitizer becomes a valuable substitute antiseptic. Choose an alcohol-based sanitizer, and one that has an alcohol content of at least 60% (you can check that on the label). If the concentration is below 60%, it may not kill as many types of germs or may simply slow down the growth of germs rather than eliminate them. Just like hand-washing, there’s a right way to use hand sanitizer, according to the CDC:
- Squeeze or pump the recommended amount into one palm.
- Rub your hands together, coating every surface (don’t forget the backs!) until the gel has dried. That will take around 20 seconds.
If your hands have visible dirt or grime or have come in contact with a harmful chemical (such as pesticide, for instance), you will want to clean them with soap and water—hand sanitizer will likely not be a very effective disinfectant in those situations.
Remember, hand-washing is always best, but hand sanitizers have their place.
“Hand sanitizers are not guaranteed to keep you completely safe from the spread of any illness—they don’t eliminate all kinds of microbes but are effective in reducing a number of them,” says Dr. Williams. “So, it’s always good to keep your hands clean, wash them with soap and water, and keep a bottle of hand sanitizer on standby in order to reduce the amount of germs you come in contact with by touching objects.”