Ventilation is used for three general purposes:

Remove air contaminants from a worker's breathing zone and work area,

Prevent the accumulation of flammable or combustible gases or vapours; and,

Prevent oxygen rich or oxygen deficient atmospheres.

For processes such as welding, brazing, soldering, and torch cutting, the primary purpose of ventilation is to remove air contaminants from the worker's breathing zone.

Different ventilation strategies may be needed in each case to remove air contaminants from the welder's breathing zone. General guidelines have been published in the CSA standard W117.2 Safety in welding, cutting, and allied processes, and the ANSI (American National Standards Institute) standard Z49.1 Safety in Welding and Cutting.

Whenever ventilation is used as a means of worker protection, the ventilation system should be used and maintained in accordance with acceptable procedures.

Where ventilation alone cannot adequately protect the welder, personal protective equipment (respirators) may also be used. Select the appropriate respirator according to the hazards present, any applicable legislation, and/or to the CSA standard Z94.4 Respiratory protection.

Please also see the OSH Answers on respirator selection, respirator care, and wearing a respirator.