The Sanitary Ordinance, also known as the Cubic Air Ordinance was a law passed in San Francisco, California on July 29, 1870. The ostensible purpose of the law was to prevent unsafe tenement conditions as the city grew. Under the law, boarding houses were required to have 500 cubic feet (14,000 L) of air in a room for each occupant. The penalty for violating the ordinance was a fine of $10–$500, 5–90 days in jail, or both, imposed on both the landlord and the occupants.
Even though many areas of San Francisco had overcrowding, this ordinance was only enforced in Chinatown and was passed as an anti-Chinese measure by Thomas Mooney and Hugh Murray—President and Vice President, respectively, of the Anti-Coolie Association. They seized upon the dissatisfaction of White workers and submitted a request to the county board of supervisors for a sanitary measure against the Chinese. Because most Chinese could not afford a fine to stay out of jail, many chose to stay. The ordinance was eventually overturned due to overcrowding of the jails.