Over the last year, hand sanitizer has become an essential part of our personal COVID-19 toolkits. And that's unlikely to change any time soon: the Centers for Disease Control and Prevention (CDC) recommends that even those who've been fully vaccinated continue to take steps to slow the spread of the coronavirus, which includes using hand sanitizer when soap and water aren't available.
So yeah, having a supply of hand sanitizer is a pretty sensible move. But don't go stockpiling until you know about hand sanitizer expirations.
Can-Hand-Sanitizer-Expire-Heres-What-Experts-Say-AdobeStock_49117041-gif , PhD, professor in the Department of Microbiology, Immunology, and Pathology at Colorado State University. "The concentration of the two active ingredients, alcohol and hydrogen peroxide, decreases over time," Dobos tells Health. "The alcohol concentration decreases through evaporation, and the hydrogen peroxide concentration decreases through conversion to water."
The good news is that if you use hand sanitizer regularly, you'll probably finish the bottle long before its expiration date. If it's stored unopened and in a cool, dry place, it could last up to 12-18 months, Dobos says. She suggests treating hand sanitizer like you do your sunscreen sprays and insect repellents and replacing it if it's not been used in about a year or so.
As an over-the-counter drug product, hand sanitizer generally must list an expiration date unless the manufacturer has data showing that the product is stable for more than three years, according to the US Food and Drug Administration (FDA).
"All items sold with pharmaceutically related uses are required to have expiration dates," William L. Schreiber, PhD, chair of the Department of Chemistry at Monmouth University in New Jersey, tells Health.
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Where you store your hand sanitizer affects its expiration
So yes, most hand sanitizers have expiration, or use by, dates. However, those dates are just estimates, since all sanitizers are stored or used under different conditions and, therefore, lose their potency at different rates.
One thing that's guaranteed to speed up the evaporation of the alcohol and the conversion of hydrogen peroxide to water (and therefore speed up the expiration date) is leaving it in a hot car, Schreiber warns; although it should be fine to keep a small bottle of it in your glovebox for short periods. (The FDA advises against storing hand sanitizer in a car during the summer months.)
"How long a sanitizer lasts is definitely a function of storage conditions," Schreiber says. "The alcohol will certainly evaporate faster in a hot car than most other storage conditions, rendering the product ineffective."
In general, the experts recommend storing hand sanitizer at a temperature of 45 to 75 degrees Fahrenheit, and always out of reach and sight of children.
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Is it safe to use expired hand sanitizer?
If you've realized you've been using hand sanitizer that's past its use by date, don't worry—it's not a massive issue, and it's definitely not harmful. "Expired hand sanitizer isn't dangerous," Dobos says. "But it is less effective."
And it's better to use expired hand sanitizer than nothing at all—a situation Dobos has found herself in. "When hiking or at the park with my kids, when there's nothing to wash our hands with—especially in winter when the water is turned off—expired hand sanitizer is definitely better than nothing," she says.
Expired hand sanitizer may be less effective because the disinfectant properties are weaker, but the physical motions you go through to apply it (known as mechanical washing) is still a plus, Dobos adds. "Since hand sanitizers also contain some glycerol (or aloe), this helps break up dirt with mechanical washing," she explains.
Schreiber advises using your best judgment. "If a bottle has never been opened, but is near or past its expiration date, it's likely to be OK," he says.
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Can you tell if hand sanitizer is expired?
Apart from checking the expiration date, it's not easy to tell if hand sanitizer is expired. "The alcohol used for hand sanitizer has to go through a process known as 'denaturation' (since it is not to be consumed), which results in a slight aroma," Dobos explains. The purpose of this process is to make it less appealing to ingest, according to the FDA. Basically, the denatured alcohol makes the hand sanitizer taste bad and deters kids from digesting it—once they've had a taste, they won't want to continue eating it.
While Dobos doesn't necessarily endorse "smelling" hand sanitizer, she suggests putting some on a surface and wafting your hand over it to smell, and therefore determining whether the alcohol content is still reasonably high. (FYI, the CDC recommends using hand sanitizers that contain a minimum of 60% alcohol.)
Another good indication that the alcohol content is still reasonably high is seeing how viscous (aka thick) the sanitizer is, Dobos adds. If it's looking pretty thick and gloopy, or takes longer to dry on application than it used to, it's probably time to replace it.
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