Key learning points
- Self-administered rapid antigen kits have an expiration date printed on the packaging.
- Proper storage of test kits is critical to ensuring they work properly and accurately.
- Using expired test kits is not recommended because they can give inaccurate results, experts say.
Rapid home COVID-19 testing (or rapid antigen testing) has become increasingly popular in recent months. These tests can be purchased over the counter and administered at home, with results in 30 minutes or less.
It is useful to have several of these rapid test kits at home if you are trying to distinguish whether you have allergies, the flu or COVID-19. They can also put you at ease before attending gatherings where you could endanger other people.
That said, don’t keep them too long as they have an expiration date.
When do rapid COVID tests expire?
Rapid antigen test kits can only be stored for a few months to a year.
“At home COVID-19 rapid antigen tests have an expiration date, which can be found on the box, and it’s important to verify this before starting the test,” Christopher Scuderi, DO, a primary care physician at the University of Florida Health Jacksonville, told IPS , to Verywell. “We continue to learn more about the stability of COVID-19 home tests or rapid antigen test kits.”
The shelf life of test kits generally varies between different manufacturers. For example, the RapCov Rapid COVID-19 Test can be stored for eight months. Meanwhile, the shelf life of two antigen tests, namely the BinaxNOW COVID-19 Ag Card and CareStart COVID-19 Antigen Test, was extended to 12 months after the Food and Drug Administration (FDA) reviewed their stability studies.
“To ensure the accuracy of the test, tests must be used within the correct time frame,” Scuderi said.
How should you store test kits?
The expiration date of the test kit is not the only factor that can affect the quality. The way you store it also matters.
“You should store your test according to the storage instructions on the package,” Scuderi said. “It is important to note that storage conditions are important and storing the test outside of these parameters can affect the accuracy of the test. Be sure to read the temperature and storage recommendations clearly before using a specific test.
Rapid antigen tests are not designed to withstand moisture, extreme humidity, or freezing temperatures. The Clip COVID Rapid Antigen Test, for example, should be stored at 59°F to 86°F (15°C to 30°C).
Tests should not be refrigerated or frozen. Although the BinaxNOW COVID-19 Ag card can be stored at 2 to 30°C, the test components should be at room temperature before use.
“Home tests are generally kept at room temperature, but that means a relatively regulated room temperature, not the back of a hot car or a car in the winter,” Sheldon Campbell, MD, PhD, FCAP, associate director of Yale Medicine’s clinical microbiology lab and professor of laboratory medicine at Yale School of Medicine, Verywell told. “Both extremely high temperatures and freeze-thaw can ruin these kits.”
In general, all individuals should follow the instructions provided in the box regarding the storage, expiration, and testing procedure of antigen tests to ensure they are working as intended.
“While these tests seem very simple, they are quite complicated little devices with many parts that have to work to give the correct answer,” Campbell said.
What this means for you?
COVID-19 Rapid Antigen Test Kits have an expiration date marked on the package. Do not use expired tests or you risk getting an inaccurate result.
Can you use an expired test?
Using an expired rapid antigen test is unwise.
“Depending on the design of the test, it may give you a false positive or negative test [result]’ said Campbell. “Do not do it. A wrong test is worse than none at all.”
Receiving a false result from a diagnostic test can be dangerous. If you get a false negative, you could infect others while going about your usual activities.
“If you use an expired rapid antigen test, the test results may not be accurate,” Scuderi said. “It’s important to note that antigen testing is very good at diagnosing a positive test, especially if you’re showing symptoms. If it’s positive, there’s a good chance you have COVID-19.”
Please note that symptomatic or not vaccinated individuals who receive a negative result are advised to retest.
“If you are symptomatic after being exposed to someone with COVID-19 and your rapid test is negative, you should call your primary care physician and consider getting a molecular PCR test,” Scuderi said. “Your primary care physician can help with diagnosis and treatment options if you test positive, and can also help determine how long you should be quarantined for, depending on your vaccination status and other health conditions.”
The information in this article is current as of the date listed, which means newer information may be available as you read this. For the latest updates on COVID-19, please visit our coronavirus news page.