(a) The dry heat method may be used to sanitize mattresses, box springs, or similar items covered in whole by a porous material or fabric.

(b) In sanitizing by the dry heat method a temperature of 230 degrees F. shall be maintained in all parts of an approved chamber for such a period of time as may be necessary for sanitization, which shall in no case be less than one hour and 15 minutes. All chambers shall be equipped with racks or devices and the articles to be sanitized shall be so placed therein so that complete circulation of heat and gases around every article being sanitized shall be attained. All chambers shall be insulated sufficiently to insure maintenance of temperature and shall be tightly sealed to prevent any leakage of gases. A thermostat shall be connected with the heating device to provide and maintain a reasonably uniform temperature at 230 degrees F. + (plus or minus) 5 degrees.

(c) The sanitization conditions of 230 degrees F. for not less than 1 hour and 15 minutes may be changed to conditions of 205 degrees F. for not less than 1 hour and 30 minutes for foam products which suffer physical degradation at the 230 degrees F. temperature.

(d) A suitable recording device approved by the bureau shall be installed and maintained to record the time and temperature prevailing during the entire operation.

(e) Each chamber in which the dry heat method of sanitization is performed shall be equipped with a fresh air inlet and an exhaust fan and duct discharging to the outside air. To clear the chamber of gases and fumes upon completion of the sanitization cycle, the fresh air inlet to the chamber shall be opened and the exhaust fan operated for 30 minutes or until all fumes have been exhausted through the discharge duct. The sanitized articles may then be removed from the chamber.

(f) When more than one sanitization chamber is operated on any premises by the same person, each chamber shall be permanently identified by a letter, beginning with “A” and proceeding in alphabetical order.