The FDA website has a breakdown showing the shelf life...

The FDA website has a breakdown showing the shelf life of about two-dozen COVID-19 at-home test kit brands. Credit: Newsday/William Perlman

Don’t toss out that at-home COVID-19 test kit just yet. You might be able to use it later than the box says.

More than 600 million free tests have been distributed to Americans under a government program begun earlier this year as the omicron surge peaked. That program ran out of money and was suspended this month. But while the labels on unused tests might list a past expiration date, the kits actually might not be expired.

Here are some questions and answers about when you should and shouldn't use tests past the label's expiration date.

How do I find out the latest I can still use a test and get valid results?

The answer depends on the manufacturer and batch number. Check details on the box against a list corresponding to each of the nearly two dozen test brands at fda.gov/medical-devices.

How can tests labeled with a specific expiration date be stretched to a later period?

The manufacturers provided the Food and Drug Administration with updated data to show that certain tests actually last longer than initially thought based on initial data. Some tests can be used for months beyond the expiration date listed on the box.

“Once the test manufacturer has more stability testing results, such as 12 or 18 months, the test manufacturer can contact the FDA to request that the FDA authorize a longer shelf-life,” the FDA said earlier this year.

Is the expiration date extended on every brand of COVID test?

No. Some tests, such as Watmind USA’s Speedy Swab Rapid COVID-19 Antigen Self-Test, Xiamen Boson Biotech Co. Ltd.'s Rapid SARS-CoV-2 Antigen Test Card and the Quidel Corp.'s QuickVue At-Home OTC COVID-19 Test, retain the listed expiration date, according to the FDA.

What happens if I use an expired test?

“COVID-19 tests and the parts they are made of may degrade, or break down, over time. Because of this, expired test kits could give inaccurate or invalid test results,” the FDA says.

Even if a test isn’t expired, are there factors that could produce inaccurate results?

Yes, if the test is taken in extreme heat or cold, according to the FDA.

“In order to ensure appropriate test performance with a test that is delivered to you in below freezing temperatures or in very hot temperatures, you should bring the package inside your home and leave it unopened at room temperature for at least two hours before opening it," the FDA says on its website.

"Once the package is at room temperature, you may open it and perform the test according to the authorized instructions for use. As long as the test line(s) appear as described in the instructions, you can be confident that the test is performing as it should. If the line(s) do not appear in the correct location(s) and within the correct time as shown in the test instructions when you perform the test, then the results may not be accurate, and a new test is needed to get an accurate result,” the administration says.

Why does the federal government say it has suspended the distribution of free at-home test kits?

Late last month, the government announced the indefinite suspension of those tests, saying Congress has not provided the necessary funding to keep the program going. Sign-up for the free tests stopped on Sept. 2.

Latest videos

Newsday LogoSUBSCRIBEUnlimited Digital AccessOnly 25¢for 5 months
ACT NOWSALE ENDS SOON | CANCEL ANYTIME