(Radio Iowa) – With cases of COVID-19 rising again, the federal government has re-started its program of offering Americans free at-home testing kits. A health official says Iowans should double-check the expiration date on any older kits they have before throwing them out — and before using them. Brian Benson, executive director of UnityPoint Health’s Pharmacy Department, says the solution you mix with the swab or the indicator panel could go bad over time. “You might get a false positive, meaning, it could indicate that you have COVID when you don’t, or you could get a false negative where it would say you don’t have COVID and you do,” Benson says, “so the accuracy could be suspect.”

The feds are now offering up to four at-home rapid tests to each household that requests them, though the tests do expire after a number of months. Benson says if you’re not sure how old your COVID test might be, don’t use it. “If there’s a question on the test and you can’t find any data, and it’s been sitting in your closet for a while or your cupboard for a while,” Benson says, “it’s probably best to, when in doubt, throw it out and get a brand new one and use that.”

The Food and Drug Administration’s website (fda.gov) has a section that indicates whether expiration dates on various tests have been extended. Order the free tests at: COVIDTests.gov.