Hot Work: Welding, Cutting, and Brazing Fire Prevention

Sparks and slag from welding and cutting can start fires well away from the work, and the fumes can harm the people doing it. 29 CFR 1910.252 asks you to make the area fire safe before work starts, protect welders and helpers, and ventilate.

Who it applies to

Section 1910.252 is the "General requirements" section of Subpart Q (Welding, Cutting and Brazing) in OSHA's Part 1910 standards. Its fire prevention duties fall on management for work "on its property", on the supervisor, and on fire watchers (1910.252(a)(2)(xiii), (a)(2)(xiv), (a)(2)(iii)(B)). Paragraph (d), on industrial applications such as transmission pipelines, is not covered here.

What the standard requires

Basic precautions

• If the object cannot readily be moved, all movable fire hazards in the vicinity must be taken to a safe place (1910.252(a)(1)(i)).
• If the object cannot be moved and all the fire hazards cannot be removed, guards must be used to confine the heat, sparks, and slag, and to protect the immovable fire hazards (1910.252(a)(1)(ii)).
• If those two requirements cannot be followed, welding and cutting must not be performed (1910.252(a)(1)(iii)).

Preparing the area

• Authorization. Before cutting or welding is permitted, the individual responsible for authorizing it must inspect the area and designate the precautions to be followed, "preferably in the form of a written permit" (1910.252(a)(2)(iv)).
• Combustibles. Where practicable, all combustibles must be relocated at least 35 feet from the work site. Where that is impracticable, they must be protected with flameproofed covers or otherwise shielded with metal or asbestos guards or curtains (1910.252(a)(2)(vii)).
• Floors. Where combustible materials such as paper clippings or wood shavings are on the floor, it must be swept clean for a radius of 35 feet. Combustible floors must be kept wet, covered with damp sand, or protected by fire-resistant shields (1910.252(a)(2)(v)).
• Openings. Where floor openings or cracks cannot be closed, precautions must be taken so no readily combustible materials on the floor below are exposed to sparks. The same goes for cracks or holes in walls, open doorways, and open or broken windows (1910.252(a)(2)(i)).
• Ducts. Ducts and conveyor systems that might carry sparks to distant combustibles must be suitably protected or shut down (1910.252(a)(2)(viii)).
• Combustible walls. Near walls, partitions, ceiling, or roof of combustible construction, fire-resistant shields or guards must be provided (1910.252(a)(2)(ix)).
• Extinguishers. Suitable fire extinguishing equipment must be maintained in a state of readiness for instant use (1910.252(a)(2)(ii)).

Prohibited areas

Cutting or welding must not be permitted (1910.252(a)(2)(vi)):

• In areas not authorized by management.
• In sprinklered buildings while such protection is impaired.
• In the presence of explosive atmospheres (mixtures of flammable gases, vapors, liquids, or dusts with air), or explosive atmospheres that may develop inside uncleaned or improperly prepared tanks or equipment which have previously contained such materials, or that may develop in areas with an accumulation of combustible dusts.
• In areas near the storage of large quantities of exposed, readily ignitible materials.

Fire watch

Fire watchers are required whenever welding or cutting is performed in locations where other than a minor fire might develop, or where any of these conditions exist (1910.252(a)(2)(iii)(A)):

• Appreciable combustible material, in building construction or contents, closer than 35 feet to the point of operation.
• Appreciable combustibles more than 35 feet away but easily ignited by sparks.
• Wall or floor openings within a 35-foot radius that expose combustible material in adjacent areas, including concealed spaces in walls or floors.
• Combustible materials adjacent to the opposite side of metal partitions, walls, ceilings, or roofs that are likely to be ignited by conduction or radiation.

The watch must be maintained for at least a half hour after welding or cutting is completed (1910.252(a)(2)(iii)(B)).

Management and supervisors

Management must establish areas for cutting and welding, establish procedures for other areas, and designate an individual responsible for authorizing the work in areas not specifically designed for it (1910.252(a)(2)(xiii)(A), (B)). It must also advise all contractors about flammable materials or hazardous conditions of which they may not be aware (1910.252(a)(2)(xiii)(D)).

The supervisor must determine the combustible materials and hazardous areas present or likely to be present, protect combustibles from ignition, secure authorization from the designated management representative, and see that required fire watches are available at the site (1910.252(a)(2)(xiv)(B), (C), (D), (G)).

Containers and confined spaces

• All hollow spaces, cavities, or containers must be vented to permit the escape of air or gases before preheating, cutting, or welding. The text adds that purging with inert gas "is recommended" (1910.252(a)(3)(ii)).
• No hot work may be done on used drums, barrels, tanks, or other containers until they have been cleaned so thoroughly as to make absolutely certain that no flammable materials are present, and no substances that might produce flammable or toxic vapors when heated. Any pipe lines or connections to the drum or vessel must be disconnected or blanked (1910.252(a)(3)(i)).
• In confined spaces, gas cylinders and welding machines must be left outside (1910.252(b)(4)(iii)).
• Where a welder must enter a confined space through a manhole or other small opening, means must be provided for quickly removing him in an emergency. When safety belts and lifelines are used for this, they must be attached so his body cannot be jammed in a small exit opening. The same paragraph requires an attendant with a preplanned rescue procedure to be stationed outside to observe the welder at all times and be capable of putting rescue operations into effect (1910.252(b)(4)(iv)).
• In confined spaces, when arc welding is suspended for a substantial period, such as lunch or overnight, electrodes must be removed from the holders and the machine disconnected from the power source (1910.252(a)(4)(i)). For gas welding or cutting, the torch valves must be closed and the gas supply positively shut off outside the confined area whenever the torch is not to be used for a substantial period. Where practicable, the torch and hose must also be removed from the confined space (1910.252(a)(4)(ii)).

Eye protection and clothing

• Helmets or hand shields must be used during all arc welding or arc cutting, excluding submerged arc welding. Helpers or attendants must be provided with proper eye protection (1910.252(b)(2)(i)(A)).
• Goggles or other suitable eye protection must be used during all gas welding or oxygen cutting (1910.252(b)(2)(i)(B)).
• Exposed employees must be protected by personal protective equipment under 1910.132 (1910.252(b)(3)).

Ventilation

• Ventilation must keep toxic fumes, gases, or dusts below the maximum allowable concentration in 1910.1000 (1910.252(c)(1)(iii)).
• For metals not covered in paragraphs (c)(5) through (c)(12), the text says mechanical ventilation must be provided and then lists three situations, with no linking word between them: (A) in a space of less than 10,000 cubic feet per welder; (B) in a room having a ceiling height of less than 16 feet; (C) in confined spaces or where partitions, balconies, or other structural barriers significantly obstruct cross ventilation (1910.252(c)(2)(i)). The next paragraph calls these "restrictions" and says natural ventilation is considered sufficient where they are not present. The minimum mechanical rate is 2,000 cubic feet per minute per welder, except where local exhaust hoods and booths under paragraph (c)(3), or approved airline respirators, are provided (1910.252(c)(2)(ii)).
• Confined spaces must be adequately ventilated to prevent the accumulation of toxic materials or possible oxygen deficiency. Where that is impossible, NIOSH-approved airline respirators or hose masks must be used (1910.252(c)(4)(i), (c)(4)(ii)).
• In areas immediately hazardous to life, a NIOSH-approved full-facepiece, pressure-demand self-contained breathing apparatus, or a combination full-facepiece, pressure-demand supplied-air respirator with an auxiliary self-contained air supply, must be used (1910.252(c)(4)(iii)).
• Where welders and helpers in confined spaces are provided with hose masks, hose masks with blowers, or self-contained breathing equipment, a worker must be stationed outside the space to insure the safety of those working within (1910.252(c)(4)(iv)).
• Fluorine compounds, zinc, lead, beryllium, cadmium, mercury, cleaning compounds, and stainless steel cutting each have their own paragraph (1910.252(c)(5) through (c)(12)).

Training

• Management must insist that cutters or welders and their supervisors are suitably trained in the safe operation of their equipment and the safe use of the process (1910.252(a)(2)(xiii)(C)).
• Fire watchers must be trained in the use of their fire extinguishing equipment and be familiar with facilities for sounding an alarm (1910.252(a)(2)(iii)(B)).
• Employees must be trained in accordance with 1910.1200 on the potentially hazardous materials in fluxes, coatings, coverings, and filler metals (1910.252(c)(1)(iv)).

The paragraphs reviewed for this guide set no retraining interval.

Written programs and records

The permit wording is "preferably in the form of a written permit", so the text does not make the written form mandatory (1910.252(a)(2)(iv)). You must include the potentially hazardous materials used in or released by welding and cutting in your hazard communication program (1910.252(c)(1)(iv)). The paragraphs reviewed set no record retention period.

Easy-to-miss requirements

• Where floors have been wet down, personnel operating arc welding or cutting equipment must be protected from possible shock (1910.252(a)(2)(v)).
• When welding on a metal wall, partition, ceiling, or roof, a fire watch on the opposite side is required where combustibles there are not relocated (1910.252(a)(2)(x)).
• Oxygen must never be used for ventilation (1910.252(c)(4)(v)).

Related guides

Fire extinguishers, Confined spaces, Respiratory protection, and Eye and face protection.

Source

This guide is based on the text of 29 CFR 1910.252 as published on osha.gov. The regulation itself always controls. States that run their own OSHA-approved State Plans may have additional or stricter rules.