29 CFR 1910 Subpart Q: OSHA Welding and Hot Work

Regulatory citation: 29 CFR 1910 Subpart Q, Welding, Cutting and Brazing (1910.251–1910.255)

What Is OSHA's Welding, Cutting and Brazing Standard?

Subpart Q sets OSHA's general industry rules for welding, cutting and brazing. Section 1910.252 covers fire prevention, eye and body protection and ventilation. Sections 1910.253 through 1910.255 cover oxygen-fuel gas, arc and resistance welding. Construction welding is covered separately in 29 CFR 1926 Subpart J.

Why Hot Work Safety Matters

Sparks, slag and heat from hot work can travel beyond the work area and ignite combustibles, sometimes in hidden spaces. Fumes and arc radiation also harm workers.

Core Requirements

1. Move or Guard Fire Hazards

If the object being welded can be moved, it must be moved to a safe place. If it can't be moved, movable fire hazards must be removed or guards used to confine heat, sparks and slag. If neither can be done, welding and cutting must not be performed.

2. The 35-Foot Rule

Where practicable, combustibles must be relocated at least 35 feet from the work. Where they can't be moved, they must be protected with flameproofed covers or shielded. Floors must be swept clean of combustibles within 35 feet.

3. Fire Watch

A fire watcher is required where more than a minor fire could develop, including when appreciable combustibles are within 35 feet, openings expose combustibles in nearby areas, or combustibles on the other side of a metal wall or ceiling could be ignited by conduction. Fire watchers must have extinguishing equipment ready, be trained in its use and in sounding an alarm, and keep watch for at least a half hour after work is done.

4. Authorization

Before work begins, the person responsible for authorizing hot work must inspect the area and designate precautions, preferably in a written permit. Hot work is prohibited in areas not authorized by management, in sprinklered buildings where sprinklers are impaired, in explosive atmospheres and near large quantities of readily ignitable materials.

5. Management and Supervisor Duties

Management must designate welding areas, name a person to authorize hot work elsewhere, ensure welders and supervisors are trained, and warn contractors about fire hazards.

6. Cylinders, Ventilation and Eye Protection

Stored oxygen cylinders must be at least 20 feet from fuel-gas cylinders or separated by a noncombustible barrier at least 5 feet high with at least a half-hour fire rating. Mechanical ventilation is required in certain spaces, such as those with less than 10,000 cubic feet per welder. Arc welders need helmets or hand shields with proper filter lenses.

Common Compliance Approaches

Use a Hot Work Permit

A written permit records the area inspection, fire watch assignment and final sign-off.

Designate Welding Areas

Set up permanent welding areas built for hot work so permits are only needed elsewhere.

Brief Contractors

Tell outside welders about flammable materials and site hazards before they start.

Example: Hot Work in Practice

A maintenance welder needs to repair a steel rack in a warehouse that stores cardboard. The maintenance supervisor inspects the area, has pallets moved more than 35 feet away, covers a nearby floor opening, and issues a written permit. A trained coworker stands fire watch with an extinguisher during the job and stays for 30 minutes after welding ends.

Related regulations: OSHA Fire Extinguishers, OSHA PPE Standards, OSHA Respiratory Protection, HSE DSEAR.

Note: This summary reflects federal OSHA requirements. States with OSHA-approved State Plans may have additional or different requirements. Always check the current regulation text and any state rules that apply to you.

Frequently Asked Questions

What is OSHA's 35-foot rule for hot work?

Where practicable, combustibles must be moved at least 35 feet from welding or cutting, or protected with flameproofed covers or shields. A fire watch is required when appreciable combustibles remain within 35 feet.

How long must a fire watch last after welding?

Under 1910.252, the fire watch must be maintained for at least a half hour after welding or cutting is completed to detect and put out smoldering fires.

Does OSHA require a written hot work permit?

OSHA requires the area to be inspected and the precautions to be authorized by the responsible person before work starts, preferably in the form of a written permit. Many employers use written permits as standard practice.