Hot Work JSA (Welding, Cutting, Grinding)

Hot work starts fires that begin hours after the welder has packed up, which is why the fire watch requirement extends past the end of the work rather than ending with it. Sparks travel, slag falls through gaps nobody mapped, and the smouldering starts somewhere out of sight.

The second half of a hot work JSA is the fume. Welding fume is a mixture that depends on the base metal, the consumable and the coating — and stainless or chrome-plated material puts hexavalent chromium, a carcinogen with its own OSHA standard, into the breathing zone.

What the work involves

• Preparing the area — removing or protecting combustibles
• Setting up cylinders, regulators, leads and ventilation
• Welding, cutting, brazing or grinding
• Maintaining a fire watch during and after the work
• Shutting down, purging and securing equipment

Hazards and controls

Controls are listed in hierarchy order — the further down the list a control sits, the less it should be carrying on its own.

1. Fire or explosion started by sparks, slag or the flame

• Eliminate: move the work to a designated area away from combustibles, or move the combustibles — relocation first, always.
• Engineering: fire-resistant blankets and screens; cover or seal openings, drains and gaps where sparks could fall through to a lower level.
• Administrative: hot work permit naming the area, the precautions and the fire watch; a watch maintained during the work and for at least half an hour afterwards, with authority to stop the job.
• Engineering: extinguishers or a charged hose at the point of work, not down the corridor.

29 CFR 1926.352(a) requires combustible material to be relocated at least 35 feet from the work site, or otherwise protected, before welding, cutting or heating. 29 CFR 1926.352(e) requires a fire watch to be maintained for at least 30 minutes after completion of welding or cutting operations to detect and extinguish possible smouldering fires.

2. Overexposure to welding fume, including hexavalent chromium

• Substitute: a process or consumable that generates less fume; remove coatings before cutting rather than burning through them.
• Engineering: local exhaust ventilation at the arc, or mechanical ventilation sized for the space — the control that actually keeps fume out of the breathing zone.
• Administrative: exposure assessment where stainless, chrome, galvanized or coated metal is involved; medical surveillance where the standard requires it.
• PPE: respiratory protection selected on the assessment, under a written respirator program.

29 CFR 1926.353(a) requires mechanical ventilation or local exhaust to keep welding fume and smoke within safe limits in confined spaces and other situations it specifies. 29 CFR 1926.1126 is the construction hexavalent chromium standard, setting the permissible exposure limit, exposure determination, controls and medical surveillance for work that generates it — stainless and coated metal welding included.

3. Compressed gas cylinder failure, leak or flashback

• Engineering: cylinders secured upright, valve caps on when not in use, stored away from heat and from each other by the required separation.
• Engineering: flashback arrestors and check valves on fuel gas and oxygen lines; regulators matched to the gas.
• Administrative: leak-test connections with a solution, never a flame; never use oxygen as compressed air or to blow down clothing; close valves and bleed lines at shutdown.

29 CFR 1926.350(a) sets the transporting, moving and storing requirements for compressed gas cylinders, including valve protection caps and securing cylinders against falling. 29 CFR 1926.350(d) sets the service piping and hose requirements for fuel gas and oxygen, including leak testing and the condition of hose and connections.

4. Arc eye, burns and UV exposure to the welder and to bystanders

• Engineering: welding screens or curtains so passers-by are not flashed; shield the work area.
• Administrative: warn anyone working nearby before striking an arc; keep bystanders out of the line of sight.
• PPE: helmet with the correct filter shade for the process and current, flame-resistant clothing covering skin, gauntlets and boots.

29 CFR 1926.102(b) requires employees exposed to the hazards of welding to be provided with eye and face protection with filter lenses of a suitable protective shade. 29 CFR 1926.351(e) requires employees exposed to the hazards of arc welding to be protected, and bystanders to be protected by shields or warned not to watch the arc.

5. Hot work inside a tank, vessel or other confined space

• Eliminate: do the work outside the space wherever the job allows.
• Engineering: purge and test the atmosphere; continuous forced ventilation; remove the gas supply and torch from the space whenever it is left unattended.
• Administrative: permit-required confined space entry procedures with an attendant and rescue arrangements, on top of the hot work permit — both, not either.

29 CFR 1926.352(g) requires that where welding is done in a confined space and the torch is left unattended, the gas supply be shut off at a point outside the space and the torch and hose removed from it. 29 CFR 1926.1203 requires confined spaces to be evaluated and, where they are permit-required, entry to be controlled by a written permit program.

A worked example row

This is how one line of the finished JSA reads, with the risk bands scored on the same 4-band matrix the generator prints:

Related work activities

• Confined Space Entry JSA
• Live Electrical Work JSA
• Hazardous Chemical Handling JSA