Whenever hydrocyanic acid gas and other dangerous gases and fumes are used for fumigation, a sufficient number of guards shall be kept at the entrance or entrances to the building or place to be fumigated, in order to prevent any person from entering such building or place while the gas remains therein. Such guards shall remain on duty until after the building or place is opened for airing, and until the gas has been completely dispelled from such building or place. The fumigator shall be responsible for reopening such building or place after the fumigation, and shall be responsible for seeing that such building or place is safe for human habitation before allowing persons to enter. (Ord. 3281)