text: During application, the building is enclosed and filled with the gas for a period of time, usually at least 16–18 hours, sometimes as long as 72 hours.  The building must then be ventilated, generally for at least 6 hours, before occupants can return. California regulations are such that the tent will be on for three to five days, which includes ventilation.  In the US, sulfuryl fluoride must be transported in a vehicle marked with "Inhalation Hazard 2" placards. Most states require a license or certification for the individual applying the fumigant.
  The concentration is continuously monitored and maintained at the specified level using electronic equipment. Possible leakages are also checked by low range electronic detectors.  Reentry to the home is allowed when the concentration level is at or below 5 ppm. Sulfuryl fluoride is colorless and odorless, however, during the fumigation process, a warning agent called chloropicrin is first released into the building to ensure that no occupants remain.  Tent fumigation is the most effective treatment for the extermination of known and unknown infestations of wood-destroying insects. Heat is the only other approved method for whole structure treatment for termites in California.  Sulfuryl fluoride provides no protection from future infestations, although heavy re-infestation can take several years since drywood termites have slower growing colonies than ground termites.