When awareness about the pandemic just started to spread several months ago, hand sanitizers were impossible to find in some places. So maybe you've bought a few bottles when you had the chance or you decided to rely on whatever you had lying around the house. In any case, it seems hand sanitizer is one of those products that we will continue living with as long as the virus still holds a threat. There are a few important signs to pay attention to, that are indicating it is time to replace your hand sanitizer.
1. When the cap has been off for too long
If you notice your hand sanitizer has been left open for a period of time that exceeds a whole day, it is necessary to replace it. This is because alcohol evaporates quickly, and it is exactly this disinfectant that makes hand sanitizer effective. Once it’s gone, the sanitizer’s potency is severely weakened.
2. When it's been exposed to heat
Another way in which the alcohol might evaporate is when the sanitizer is exposed to direct sunlight or leave it in a hot car for days at a time. According to the CDC, ethyl alcohol, the kind commonly used for hand sanitizers, starts to evaporate at room temperature. Make sure to store your sanitizer bottle in a cool, dry environment.
3. If it contains less than 60% alcohol
When you buy hand sanitizer, take a look at the list of ingredients. The active sterilizing ingredients in most hand sanitizers — gel and foam — are ethyl alcohol and isopropyl alcohol. The CDC recommends using a sanitizer with at least 60 percent alcohol content. It’s best to opt for products anywhere in the 60 to 95 percent range, as some of the alcohol inevitably evaporates with everyday use. If the sanitizer only contains 60 percent, to begin with, it may quickly become ineffective.
Don’t be alarmed if you see water on the list, too. While alcohol is a key ingredient of sanitizer, water is important as well. "There is some water in hand sanitizer that helps to dissolve proteins inside pathogens so the alcohol can then kill them," explains Samantha Yammine, PhD, a neuroscientist and stem cell biologist based in Canada.
4. When the expiration date passed
Hand sanitizers have a long shelf life, but they do have an expiration date. Each product must undergo a stability test to test its shelf life. According to experts, it is usually safe to assume your hand sanitizer has gone bad if three years have passed since you purchased it. However, do take a look at the date listed on the specific bottle you have as sometimes it can expire sooner, depending on the stability of the formula.
Using sanitizers past their expiration date is not dangerous. In fact, they may still be effective, as they still contain alcohol albeit below the recommended concentration. If you are unable to access new hand sanitizer, one that’s expired might be better than none. “Some alcohol is better than nothing,” says Alex Berezow, microbiologist and Vice President of Scientific Communications at the American Council on Science and Health.
6. When the smell seems unusual
If you can’t find the expiration date on the bottle and are unsure how old your hand sanitizer is, try to give it a good whiff. Once the sanitizer expires, some of the ingredients may start to emit odors that weren’t there before. Moreover, if the smell of ethanol is weaker it's a sure sign some alcohol has evaporated.