Is dirty hardware making you sick?

Take a look at your keyboard. Is last week's lunch still decorating the space bar? What about your phone? Does the earpiece look as greasy as a spoon in a truckers' café?

Office equipment harbours millions of germs - with telephones, keyboards and mice particularly fertile breeding grounds for nasties, claims IT equipment cleaning company PROtech IT Hygiene.

The average office desk is capable of supporting some 10 million microbes, said the cleaning company, and there are nearly 21,000 microbes per square inch in the average office.

Unsurprisingly, the filthiest equipment is the hardware that gets handled most. Telephones are the worst offenders, holding up to 25,127 microbes per square inch, while computer keyboards, which are well placed to catch morsels of lunch, sneezes and dead skin and hair, can be germ-ridden to the tune of 3,295 microbes per square inch and mice can harbour up to 1,676.

Enough dead skin falls off a human in a day to fill a teacup, according to the company, which said some cold and flu viruses can survive on surfaces for up to 72 hours.

Unclean office equipment can not only increase absenteeism among staff by exposing them to germs that cause colds and flu but may also cause the hardware itself to malfunction, the company warned.

While disinfecting equipment might be simple, getting staff to clean themselves is probably much harder: 31 per cent of men and 17 per cent of women admit they do not wash their hands after going to the toilet.