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The Food and Drug Administration just pointed out something about bottles of hand sanitizer people are hoarding during the coronavirus pandemic: They have an expiration date.

It's likely few notice the fine print while grabbing handfuls off shelves in recent weeks. It's hard enough just to find a bottle lately.

Should we worry, given 86,000 Americans have been infected with COVID-19?

The FDA has good and .

Good news: Adding some kind of expiration date is a standard on all over-the-counter drug products "unless they have data showing they are stable for more than three years," the agency said Thursday.

Bad news: "FDA does not have information on the stability or effectiveness of drug products past their expiration date."

So, if the expiration date on your is pre-2017, you're gambling on effectiveness.

The chief concern, according to Healthline.com, is that alcohol is a key ingredient of and it evaporates when exposed to air. If the bottle is not airtight, the percentage of alcohol diminishes.

"The manufacturer estimates how long it will take for the percentage of the to drop below 90% of the percentage stated on the label," Healthline.com says. "That time estimate becomes the expiration date."

The FDA is not offering advice on what to do with expired sanitizer, but emergency measures implemented to speed up production suggest the agency is willing to ignore expiration dates for the time being.

"Hand sanitizer produced under the temporary policies for hand sanitizer production and compounding may not have an expiration date listed because they are expected to be used during this public health emergency," the agency says.

Washing hands often with soap and water for at least 20 seconds is one way to stop the spread of the virus, according to the Centers for Disease Control and Prevention.

"If soap and water are not available, CDC recommends consumers use an alcohol-based hand sanitizer that contains at least 60% alcohol," the agency reports.

Meanwhile, "FDA recommends that consumers do not make their own hand sanitizer. If made incorrectly, hand sanitizer can be ineffective, and there have been reports of skin burns from homemade hand sanitizer."