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Why you shouldn't throw out that expired COVID test just yet

covid test kit on table with green background
iHealth Labs

Editor's Note: Various varieties of at-home COVID-19 tests have also had their expiration dates extended by the FDA. Here are two additional resources:

You can check multiple brands here.
You can check Pilot COVID-19 At-Home Test distributed by Roche here.

The expiration date printed on your at-home COVID-19 test kits may not be accurate. Lost in the summer news cycle was the fact that the U.S. Food and Drug Administration approved an expiration date extension for the free tests offered by the federal government. These are the ones in the orange and white packaging as seen above.

The tests produced by iHealth Labs were granted a three month extension "based on the results of your ongoing stability studies," the FDA told iHealthin July 2022. That means, as of July, the tests are good for up to a year.

That same month, the company said, "We will continue to apply to (the) FDA for shelf-life extensions every three months based on our stability studies, and the new shelf-lives for our tests will apply to tests already produced as well as future production."

Some people have noticed the dates inside the test kits do not match the outside. In a statement to WVXU, the company says "This is because naturally each component/item has its own expiration date, but the expiration date printed on the box is determined by the item having the shortest shelf life. For our antigen tests, it’s the Test Cassette."

The company has a tool on its website to help you figure out the updated expiration date. All you'll need is the lot number on your packaging.

However, the company writes, "As of now, the shelf life of iHealth tests were extended to 12 months, making all our tests still valid to use."

Click here for the expiration checking tool.

Faulty tests

In October, the South Carolina Department of Health and Environmental Controlissued a release stating it had "determined that a limited number of the iHealth COVID-19 at-home test kits may have faulty result cartridges because of a manufacturer error. These may return inaccurate results, including an absent or very faint control line."

The agency says the affected lots are:

  • 221CO20130 Exp: 7/29/2022
  • 221CO20103 Exp: 7/2/2022
  • 221CO20124 Exp: 7/23/2022

How the FDA determines expiration dates

The FDA provides this Q&A in its FAQ:

"Q: How is the expiration date determined for an at-home COVID-19 diagnostic test? (4/28/22)

"A: COVID-19 test manufacturers perform studies to show how long after manufacturing COVID-19 tests perform as accurately as the day the test was manufactured. The shelf-life is how long the test should perform as expected and is measured from the date the test was manufactured. The expiration date listed on the box label for at-home COVID-19 tests is set at the end of the shelf-life and is the date through which the test is expected to perform as accurately as when manufactured.

"The testing to determine this time period is called stability testing because it is confirming the time period over which the performance is expected to remain stable. There are different types of stability testing. The most accurate is real-time stability testing, where the manufacturer stores the tests for the time period of the proposed shelf-life (plus a little extra time to ensure the expiration date can be relied upon) and then evaluates its ability to perform accurately. For example, for a proposed 12-month shelf-life, the manufacturer would evaluate the performance after storing the test for 13 months.

"In some cases, accelerated testing provides a faster way to estimate the stability of a test's performance over time by storing the test for a shorter time at a higher temperature, and then evaluating its ability to perform accurately. However, since accelerated testing only estimates the test stability, it does not provide as much assurance as real-time data, especially for longer time periods. Based on experience with tests and stability testing, accelerated testing typically provides sufficient assurance to label tests with a shelf-life of up to six months.

"Since it takes time for test manufacturers to perform stability testing, the FDA typically authorizes at-home COVID-19 tests with a shelf-life of about four to six months from the day the test was manufactured, based on initial study results, and it may be extended later as additional data is collected.   You can check the Expiration Date column of the List of Authorized At-Home OTC COVID-19 Diagnostic Tests to see if the expiration date for your at-home OTC COVID-19 test has been extended and how to find any new expiration date."

Updated: November 3, 2022 at 2:40 PM EDT
Various varieties of at-home COVID-19 tests have also had their expiration dates extended by the FDA. Here are two additional resources:

You can check multiple brands here.
You can check Pilot COVID-19 At-Home Test distributed by Roche here.
Senior Editor and reporter at WVXU with more than 20 years experience in public radio; formerly news and public affairs producer with WMUB. Would really like to meet your dog.