A designated hot work area is an area specifically designed and approved for hot work by the CSUDH EH&S. These areas do not require Hot Work Permits. Designated hot work areas must be inspected upon initial assignment and after any fire related incident or near miss. Re-inspections must be completed every three years, or if there is a change to the space.
Design and Maintenance of Designated Hot Work Areas
- Must be constructed of non-flammable or fire-resistive walls, doors and floor
- Openings or cracks in walls, floors, ducts or shafts must be tightly covered to prevent the passage of sparks to adjacent or hidden areas. If they cannot be covered, they must be shielded by metal fire-resistance guards. Fire-safe curtains must be provided to prevent passage of sparks or slag out of the designated hot work area.
- Must be segregated from other areas of the building with non-flammable partitions. Partitions must be securely connected to the floor with no gaps between the floor and the partition.
- Openings in partitions must be protected by welding-grade curtains or other permanent physical barriers either attached to the structure or of rugged portable construction.
- Adjacent hot work stations must be separated with flame-resistant screens or shields.
- Hot work areas must be separated from personnel in adjacent areas with use of flame-resistant screens or shields.
- Flammable materials must be removed or isolated from adjacent areas by appropriate shielding to prevent ignition from sparks, slag or heat.
- If indoors, must have adequate ventilation or smoke filtration.
- Must be equipped with both portable fire extinguishers and fire alarm systems.
- Must have signage labeling the area “Designated Hot Work Area”.
- Equipment that contains (or has contained) flammable materials must be thoroughly cleaned, dried and purged prior to performing hot work.
- Good housekeeping must be maintained.
- Keep gasses separated.
- Remove all dust, debris, flammable objects and substances from the area.
- Keep floors clean and free from trip, slip and fall hazards at all times.
Ventilation in Designated Hot Work Areas
Ventilation within the designated hot work area must be sufficient to keep concentrations of airborne contaminants that may be released during hot work below the Cal/OSHA Permissible Exposure Limits (PEL). If building ventilation is insufficient, mechanical ventilation (e.g., exhaust fans or smoke filters) must be provided. If action levels are still exceeded then operators must wear respirators.
Mechanical ventilation can include local exhaust, forced air, and/or general air movement. Local exhaust ventilation is preferred and should as close as practicable to the hot work. Forced ventilation includes fans that deliver air to workers. Forced air systems should be positioned so they move fresh air across the worker’s face. Avoid Canopy style hoods where fumes can pass from a work area through the workers breathing zone and then up and out.
General Building Ventilation
General mechanical ventilation may be necessary in addition to forced ventilation. Examples include roof fans, wall or window exhaust fans, and similar large area air movers. General mechanical ventilation is not generally effective by itself, and should be used to augment local exhaust or forced ventilation.
In locations where conditioned air or space-logistics prevent direct exhaust of smoke, a local smoke remover may be used. Smoke removers scrub hot work smoke and particulates from the air and exhaust the air back into the work area.
Cylinder Storage and Use
- Position welding fuel-gas cylinders valve end up when in use.
- Keep tops of acetylene cylinders clear of materials or obstacles which could damage the safety device or interfere with the quick closing of the valve.
- Store liquefied gases valve end up.
- Secure cylinders in an upright position with two non-combustible chains or straps. The top strap must be 1/3 of the distance from the top of the cylinder and the bottom chain 1/3 distance from the bottom.
- Store at adequate distance from welding or cutting operations so that sparks, hot slag, or flame will not reach them or have fire-resistant shields.
- Separate welding-gas cylinders by a distance of 20 feet or with a non-combustible metal partition at least 60 inches high.
For all hot work being performed in non-designated hot work areas a hot work permit must be completed. A completed and signed permit must be emailed to EH&S@csudh.edu and posted at the job site. For emergency hot work tasks, permits must be completed and posted at the job site and emailed to EH&S@csudh.edu within 1 business day after the job starts. The permit must be completed by the Permit Authorizing Individual (PAI) and permits for indoor work and outdoor work require separate hot work permits, see appendix for hot work permit.