Lateral flow tests (LFTs) have become a normal part of our lives as we learn to live with COVID-19 and ride the Omicron wave.
But although the tests at home have reached record values in the last few weeks – with over 1.7 million COVID-19 virus tests Taken on Jan 3rd alone – confusion remains about how LFTs work, whether they’re safe, and how to get them right.
To help, Rich Quelch from pharmaceutical experts origin answers the questions we googled about LFTs, from reasonable to bizarre …
Should I report a negative lateral flow result?
The public is instructed to report any results of a lateral flow test, whether positive or negative.
This is helping scientists and governments better understand the spread of the virus across the country. With only positive results, the number of COVID-19 cases looks worse than it really is. Scientists also use the information to spot patterns and breakouts faster and more accurately.
Is COVID-19 in tap water?
A TikTok video showing a positive lateral flow test from tap water has been viewed more than 10 million times, causing the public to wonder if the tap water has COVID-19 levels.
The answer is no – all tap water is sanitized before it reaches our homes. Any positive result from a liquid sample that is not intended for testing can produce inaccurate and unpredictable results. With a shortage of LFTs, don’t waste a test kit proving it.
Can lateral flow tests cause cancer?
Misinformation is spreading around the internet about how excessive exposure to ethylene oxide – the liquid used to sterilize the swabs in LFTs – can cause cancer.
While contact with large amounts of ethylene oxide can be dangerous, only a tiny amount is used for sterilization to stop the spread of infection. The MHRA has publicly confirmed that ethylene oxide is a strictly controlled and safe method of sterilization.
Does a positive result count if it appears after 30 minutes?
After completing a lateral flow test, your result will be displayed within 30 minutes. If a weak positive line appears later, it is most likely a very weak contaminant or an extremely low virus concentration that would not be communicable.
For each test, set a timer for the waiting time specified in the instructions for the test kit.
Are negative lateral flow tests recyclable?
If you test regularly at home, LFTs can produce a lot of waste. But no matter what the result is, unfortunately none of the plastic items or plastic packaging is recyclable.
Whether a positive or negative result, put all used items in a plastic bag from the multipack, close it and dispose of it with the residual waste. When you have finished your home tests, the cardboard and paper folders can be recycled.
Can an LFT smear harm your brain?
While an LFT nasal smear can feel uncomfortable, there is no risk of the smear reaching or damaging your brain.
A nasal swab goes up a passageway that leads to the marine cavity, which is covered with soft, delicate tissue. At the top of this passage is your nasopharynx, where your nose meets your throat. We’re not used to feeling this part of our body, but the more tests you do, the more comfortable you will find the experience.
Can you reuse a negative LFT test?
With a shortage of LFT tests across the country due to unprecedented demand, it might be tempting to reuse a negative LFT test.
This should never be attempted and the result will not be accurate. Because the absorbent pad is already saturated and the binding reagents on the nitrocellulose membrane have already brought the test lines to the result. This process cannot be undone and a new sample cannot overwrite a previous result.
All parts of a used test kit should be discarded after the result has been read and recorded.