Ventilation Requirements

Mechanical ventilation must be provided wherever welding or cutting is being performed under any of the following conditions:

• In a space of less than 10,000 cubic feet per welder
• In a room with a ceiling less than 16 feet high
• In confined spaces or where the welding space contains partitions, balconies, or other structural barriers to the extent that they significantly obstruct cross ventilation

Mechanical ventilation must consist of either general mechanical ventilation systems or local exhaust systems.

Local exhaust ventilation must consist of freely movable hoods intended to be placed by the operator as close as practicable to the work. This system must be of sufficient capacity and so arranged to remove fumes and smoke at the source and keep the concentration in the breathing zone within safe limits.

Oxygen is prohibited from use for ventilation purposes, comfort cooling, blowing dust from clothing, or for cleaning the work area.

Minimum Ventilation Rate

Such ventilation must be at the minimum rate of 2,000 cubic feet per minute per welder, except where local exhaust hoods and booths, or airline respirators approved by the Mine Safety and Health Administration and the National Institute for Occupational Safety and Health (NIOSH) are provided.

Contaminated air exhausted from a working space must be discharged into the open air or otherwise clear of the source of intake air. Natural ventilation is considered sufficient for welding or cutting operations where the restrictions listed above are not present.

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