This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at

Subchapter 7. General Industry Safety Orders
Group 16. Control of Hazardous Substances
Article 111. Fumigation

Return to index
New query

§5223. Fumigation in Buildings or Rooms Other Than Fumigation Vaults or Chambers.

(a) Whenever any building or section thereof, other than fumigation vaults or chambers, are fumigated with a poisonous gas:

(1) All cracks, holes, crevices, openings, and apertures in walls, floors, and ceilings shall be sealed so as to confine the gas to the rooms being fumigated.

(2) Doors and windows shall be closed and sealed; and legible warning signs shall be posted at all entrances or approaches. Signs shall state premises under fumigation and type of gas used and shall not be removed till fumigation and ventilation are complete.

(3) Employees releasing poisonous gases for fumigation shall wear respiratory protection of a type approved for use in the gas used.

(4) Fumigation of single rooms is forbidden unless such room constitutes a wing, floor, or other detached or semi-detached section of a building, or can be effectively sealed off from the remainder of the building.

(5) When a part of a building is to be fumigated, all adjoining rooms, including those above and below, and all other parts of the building or of adjacent buildings into which the gas may penetrate shall be vacated. Windows in such locations shall be open during fumigation.

(6) After the exposure is completed, premises shall be purged of fumigant and the air therein shall be tested. Employees shall not be allowed to enter the premises, except to make tests, until the concentration of fumigant is known to be safe. Employees making tests shall wear respiratory protection approved for use in the fumigant used.

(7) Purging or ventilation shall be carried out in such a manner as not to endanger employees.

(8) Where flammable fumigants are used, no source of ignition shall be allowed in premises being fumigated. When part of a building is being fumigated, no source of ignition shall be allowed in the rooms being fumigated or in adjoining rooms including those above and below, or in adjacent buildings into which gas may reasonably be expected to penetrate.


1. Renumbering of Section 5217 to Section 5223 filed 5-3-78 as procedural and organizational; effective upon filing (Register 78, No. 18).

2. Change without regulatory effect amending subsections (a)(2)-(3) filed 12-19-2002 pursuant to section 100, title 1, California Code of Regulations (Register 2002, No. 51).

Go BackGo Back to Article 111 Table of Contents