No person, firm or corporation shall use within the City and County of San Francisco, hydrocyanic gas, cyanogen or chloropicrin, or any other poisonous, noxious or dangerous gases or fumes which are dangerous to the life or health of human beings, for the purpose of fumigating, without first obtaining a permit from the Director of Public Health so to do.
Provided, however, that nothing in this Section or Section 701 of this Article shall be construed to apply to any fumigations on property of the State of California, or to mandatory fumigations under the supervision of any department of the State of California, or U.S. government.
Provided, further, that fumigations with poisonous gases conducted in warehouses on property other than that of the State of California shall be so conducted as to comply with the safety measures approved by the Department of Public Health, and the person, firm or corporation responsible for such fumigation shall notify the Bureau of Fire Prevention and Public Safety of the San Francisco Fire Department as to the exact location of said fumigation, and the time that said fumigation is to take place.