A pharmacists explains why it’s important to store lateral flow tests properly. 

You wouldn’t leave milk or food out in the heat for too long – but what about lateral flow tests?

With temperatures in many parts of the country set to soar beyond 30ºC in the coming days and week, anyone with Covid tests in their home might want to be aware of how to store them correctly – as getting too hot could damage them and alter their effectiveness.

“With temperatures reaching levels in the UK that are largely unheard of, it’s completely understandable to be concerned about safely storing your lateral flow test kits. Regular testing is one of the most important measures to protect against Covid-19, so it’s really vital to take good care of tests, to ensure you get the most accurate results,” says Giulia Guerrini, lead pharmacist at digital pharmacy Medino (medino.com).

“The guidance from the NHS is that your lateral flow test kits should be stored away from direct sunlight, at between 2ºC and 30ºC.

“That being said, you shouldn’t refrigerate them either, because storing your lateral flow kits at very cold temperatures can also reduce their reliability,” Guerrini adds.

So, unless you’re lucky enough to have air conditioning throughout your home and it’s naturally cool, you may want to think about where your lateral flow tests are being kept. Keeping them out of direct sunlight is key at all times – so be sure to move them away from areas like windowsills and worktops near windows that get a lot of sun.

“The easiest way to ensure your lateral flow kits stay in the best possible condition, no matter the weather, is to store them in a cool, dry place, out of the sun,” says Guerrini.

“For example, a medicine cabinet, kitchen cupboard or drawer will all protect the integrity of the tests, even in a heatwave.”

Why must Covid tests stay within this range?

“Storing the test at higher temperatures can irreversibly damage the swab, as well as the chemicals used in the test,” Guerrini explains.

“This means that when the time comes to take a test, your results will not be entirely reliable as the chemical make-up of the test will be altered.”