A typical elevator button harbours nearly 40 times as many germs as a public toilet seat, researchers have found.
A study carried out in hotels, restaurants, banks, offices and airports found 313 'colony forming units' of bacteria on every square centimetre of lift button.
The equivalent surface area of toilet seat had only eight units.
The bacteria on the lift buttons could include stomach bugs such as E.coli, the researchers say.
'In a busy building, a lift button can be touched by dozens of people who will have come into contact with all kinds of bacteria every hour," the Daily Mail quoted Dr Nicholas Moon, from Microban Europe, which carried out the research for the University of Arizona in the U.S., as saying.
'Even if the buttons are cleaned regularly, the potential for the build up of bacteria is high,' he added.