In a laboratory more than two centuries ago, scientists harnessed the germ-killing power of chlorine for the first time - and production of bleaching powder began. No-one has identified a more ruthlessly efficient way of killing germs since.
The oldest things are often the best; Domestos arrived on the grime scene in 1929. It was originally sold in stone-ware jars that were refilled by door-to-door salesmen. Now you can even get it in pink plastic bottles with a specially-designed nozzle to hunt down germs in hard-to-reach places.
In the 1950s Domestos made a stand on health education in Britain - introducing public awareness campaigns helping to teach people how to prevent typhoid, dysentery and gastroenteritis.
Now more than 10 million households rely on Domestos to keep their homes safe from germs.