Hot Work (including Welding, Cutting and Heating) >> Hot Work in Enclosed Spaces

Figure 1: Fire extinguisher ready for use during hot work.
Figure 1: Fire extinguisher ready for use during hot work.

Hot work is often performed in enclosed spaces and may expose workers to hazards. Listed below are the specific safety and health requirements for the majority of hot work operations. (Please see additional requirements for hot work in confined spaces and other locations.)

Specific Safety and Health Requirements

This module outlining the requirements for Hot Work in Enclosed Spaces must be reviewed for the basic requirements before reviewing the module regarding hot work requirements for Confined Spaces and Other Locations.

Note: Confined space entry is one of the leading hazards associated with barge cleaning. Review the Shipbreaking: Confined or Enclosed Spaces and Other Dangerous Atmospheres chapter for information on how to protect workers from this hazard.

Figure 2: Reviewing of Marine Chemist Certificate.

Potential Hazards

Figure 3: Removing of flammable and combustible material.

Workers performing hot work or working in spaces adjacent to hot work are exposed to the following risks:

Figure 4: Fire extinguisher ready for use during hot work.
  • Fire and explosions caused by flammable or combustible materials or airborne gases, vapors, and particulates
  • Toxic gases and metal fumes produced from the hot operations (such as nitrogen oxides, and lead fumes)
  • Ultraviolet radiation from electric arcs

Requirements and Example Solutions

Figure 5: Inspecting welding equipment.

Before beginning hot work, the following tasks must be performed:

Figure 6: Leak test

Remember: When hot work is being performed, it is the employer's responsibility to ensure that precautions are taken in adjacent spaces. [29 CFR 1915 Subpart P]

Figure 7: Burner wearing respirator, tinted face shield and leather gloves.
Figure 8: Welding UV screens.
Figure 9: Welding torch.
Figure 10: Inspection to maintain safe conditions.

Potential Hazards

The work space is initially inspected by a Certified Marine Chemist or a Shipyard Competent Person. Conditions may change during work so the Shipyard Competent Person must inspect the hot work area as often as necessary. If the Shipyard Competent Person discovers a change that could adversely alter safe conditions (such as ventilation failure, piping system leak, or hazardous materials spill), work must be stopped. Work may not be resumed until the affected space is visually inspected and re-evaluated (by a Marine Chemist, if a marine chemist certificate was issued) to meet requirements. [29 CFR 1915.15(f)]

Requirements and Example Solutions

Examples of items that can change conditions include:

  • Temperature changes: increased or decreased temperatures affect flammable and toxic vapor levels.
  • Type of work in tank: leaking torches, use of cleaning solvents, and removal of tank residue ("mucking out") may alter atmosphere.
  • Unattended tanks or spaces: if a period of time has elapsed, it is recommended that spaces be retested before re-entry and continuation of work.[29 CFR 1915 Subpart A and Subpart B]
  • Ballasting or trimming: changing the position of the vessel could release hazardous materials into a space or compartment.
  • Ventilation changes: ventilation duct damage or fans not in use.
  • It is recommends that tests before re-entry and continuation of work in unattended tanks and spaces should be conducted at the beginning of the shift and then at least every 24 hours between tests.
Figure 11: Deck edges guarded by temporary clamp-on guardrail.

Fall hazards are a leading cause of shipyard fatalities. Shipyard employees are often required to work in dangerous environments that may include fall hazards. Accidents involving elevation equipment such as ladders, scaffolds, and aerial lifts are often serious, even fatal. Workers also risk falls from open deck edges.

Potential Hazards

Deck Openings and Edges

  • Falls from deck edges
  • Falls from deck openings
  • Falls into open holes


  • Falls from ladders
  • Falls from scaffolds

Requirements and Example Solutions:

Personal Fall Protection

  • If fall hazards are identified through the Hazard Assessment required in 29 CFR 1915.152(b), employees must be protected from falls by the use of personal fall protection equipment. [29 CFR 1915.152(a)]
  • Guard rails may be used in lieu of personal fall protection, even though they are not required in shipbreaking. For guard rail specifications, see 29 CFR 1915.71(j).

Fall Protection for Scaffold Work

  • Guardrails or other appropriate fall protection must be used when working on scaffolds 5 feet above surfaces. [29 CFR 1915.71(j)]

For more detailed information, review Personal Fall Protection Equipment.

Figure 12: Local exhaust ventilation works.


Potential Hazards

Workers performing hot work operations are exposed to toxic gases and metal fumes (such as but not limited to nitrogen oxides, zinc, or iron oxide fumes) that may cause occupational illnesses.

Requirements and Example Solutions

Ventilation removes or dilutes metal fumes and gases generated by hot work. The following ventilation requirements must be met:

Figure 13: Typical gas manifold. Figure 14: Fire watch.

Potential Hazards

Workers performing hot work in enclosed spaces are exposed to the risk of fires from ignition of flammable or combustible materials in the space and from leaks of flammable gas into the space from hot work equipment.

Requirements and Example Solutions

Fires caused by hot work in enclosed spaces can be prevented with the following precautions:

  • Performing hot work in a safe location, or remove or cover fire hazards. [29 CFR 1915.503(a)]
  • Make suitable fire extinguishing equipment immediately available and ensure that personnel assigned to use this equipment are adequately trained. [29 CFR 1915 Subpart P]
  • Do not place gas manifolds in enclosed or confined spaces. [29 CFR 1915.55(e)(2)]
  • Take the above precautions in all adjacent spaces.[29 CFR 1915 Subpart P]

Note: OSHA Shipbreaking standards do not require a firewatch, however a firewatch is typically used and may be required by a marine chemist or local authority.

Figure 15: Respiratory protection. Figure 16: Welding PPE.

Potential Hazard

Injury and illness may be caused by hot work (such as welding fumes, UV light, sparks, noise, skin injury).

Example Solutions

Personal protective equipment is used during hot work to protect workers. A PPE program consists of the following:

For more specific information, see PPE Selection: Hot Work.