A local government in central Japan has ordered smokers to complete a 45-minute “decontamination period” between stubbing out their last cigarette and using lifts in the city hall.

Staff at the administrative offices of the city of Ikoma, in Nara Prefecture, are being told to either take the stairs after a cigarette break or to wait for three quarters of an hour before using an elevator in the five-storey building.

The new regulation was introduced because “exhaled air from smokers could cause passive smoking and the impact is especially serious in closed spaces”, the local government said.

The office has, however, stopped short of imposing punishments upon anyone who ignores the rule.

“This is one measure we can take against the problem of passive smoking and we believe it is really important for human health, especially for children and pregnant women”, said Kosuke Izumi, a city government official.

Mr Izumi - not a smoker himself - says that city employees “understand and accept” the reasoning behind the ban, although some of the smokers have grumbled.