Dishwashers were found to be particularly effective: the high-temperature spray, splashing against the crockery and cutlery, results in a nasty plume of toxic chemicals that escapes when the door is opened at the end of the cycle.

ECONOMIST: Indoor pollution

Dr Michel Alary, an Aids specialist in the department of medicine at Laval University and the Saint-Sacrement Hospital Research Centre, said that the extremely high temperatures in sub-Saharan African countries could prevent the gel working there if it requires room temperature to be effective.

BBC: Condoms