Choking hazard

Young children should stay out of the kitchen, and not just because of hot
stoves. Most kitchens with a gas oven are polluted with unsafe levels of
nitrogen dioxide, according to a survey of 876 homes in England by the Building
Research Establishment in Watford. The concentrations of NO₂ in the air
frequently exceeded both the World Health Organization annual limit of 40
micrograms per cubic metre and the hourly limit of 200 milligrams per cubic
metre, says Jeff Llewellyn of the BRE. That’s high enough to make breathing
difficult for young children.