Most people know that washing your hands can help to prevent passing on nasty viruses and bacteria. But how many people just flick their hands under a dribbling tap and think that will do? Now hopeless hand washers will be caught with glowing green fingers by a good hand-washing test.
A new hand-washing training kit uses a cream containing a harmless dye that glows green in ultraviolet light to show up shoddy hand washing. Demonstrators put a blob of cream on people’s hands and send them away to wash them. When they come back, they are often amazed at how much glowing green dye remains on their fingers. If the dye were a microbe, they would be standing a good chance of infecting themselves and passing it on to other people.
The glowing cream can also be used to show how viruses such as those that cause colds and flu can survive on hard surfaces and be spread from hand to hand. Just touching a doorknob that has had a little of the special cream applied to it can make people’s fingers turn green under UV light — and then when they touch another person’s hand the green glow gets passed on.