Why you shouldn't keep your office mug on your desk.

Look around your office desk and chances are you have a mug (or maybe a few) sitting amongst the rest of the debris.

It’s probably your favourite mug, one you’ve claimed as your own from the office stash and keep on your desk to use daily (and to prevent anyone else from stealing it).

THROW IT OUT RIGHT NOW.

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Not only is it harbouring yesterday’s teabag, but it’s also a bacterial cesspool that could actually make you very sick.

“Colonies of germs are living in your favourite cup,” Charles Gerba, PhD, a professor of environmental microbiology at the University of Arizona recently told Men’s Health.

According to his research, 20 per cent of office mugs carry fecal bacteria while 90 per cent are covered in other germs.

Take your pick. Image: iStock

Oh god.

Apparently it's all to do with the way we clean them, with most people opting for a quick rinse with a bacteria-covered sponges rather than the dishwasher. Doing so means the bacteria transfers from sponge to mug, which it can survive in for three days.

Leave it on your desk unwashed over the weekend and it's even worse. (Post continues after gallery.)

Gerber says this allows germs to start reproducing immediately - and colonies of bacteria are able to grow even when there's nothing more than a coffee ring in your cup.

If you're still not convinced, you can expect similar results from any other crockery or cutlery you give a half-assed wash after use.

Image: iStock

Fortunately, there is a solution.

Gerber advises taking home your mug daily to be washed in the dishwasher (if there's not one in the office) and ensure that it goes through the dry cycle which will kill every last germ with the hottest temperatures.

If that's too much, at least wash it properly with hot water, soap and a paper towel. Please.

Image: iStock.