Requirements for Non-Covered Metals
When welding or cutting is done on metals not covered by OSHA 1910.252, provide mechanical ventilation in the following locations:
- Spaces of less than 10,000 cubic feet (284 m3) per welder
- Rooms having a ceiling height of less than 16 feet (5 m)
- Confined spaces
- Welding spaces that contain partitions, balconies, or other structural barriers that significantly obstruct cross-ventilation
Minimum rates: Ventilation must be at the minimum rate of 2,000 cubic feet (57 m3 ) per minute per welder. An exception to this requirement is when approved local exhaust hoods and booths or respirators are provided. Natural ventilation is sufficient for welding or cutting operations where the restrictions above are not present.
Local exhaust hoods and booths: Mechanical local exhaust ventilation may be either of the following:
- Hoods: The welder should place freely movable hoods as near as possible to the welded work. These hoods should have a rate of airflow of 100 linear feet (30 m) per minute in the zone of welding at the hood farthest from the point of welding.
- Fixed enclosures: A fixed enclosure must include a top and at least two sides that surround the welding or cutting area, and it must provide airflow sufficient to maintain a velocity of at least 100 linear feet (30 m) per minute directed away from the welder.
Screens: When welding in a space entirely screened on all sides, arrange the screens so no serious restriction of ventilation exists. Mount the screens so they are about 2 feet (0.61 m) above the floor unless performing the work at so low a level that the screen is extended nearer to the floor to protect nearby workers from the glare of welding.
5-4. When is mechanical ventilation required where welding or cutting is done on metals not covered by OSHA 1910.252?
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