While the provided documents don't explicitly mention Job Hazard Analysis (JHA) for welding, they do emphasize key safety measures that would be integrated into a JHA for welding activities. Here's a breakdown of essential considerations for welding safety, which would be included in a JHA:

1. Fire Prevention:

• Before starting any welding or cutting, the area must be inspected to ensure it is safe [1]. Combustible materials, dust, gas, or vapor should be removed, or alternate methods to render the area safe should be implemented [1]. Cutting and welding should be scheduled so that plant operations that might expose combustibles to ignition are not started during cutting or welding [2].
• Relocate combustibles at least 35 feet from the work site. If relocation is not possible, protect combustibles with flame-proofed covers or shields [3]. Ensure edges of covers are tight to prevent sparks from going under them [3].
• Ducts and conveyor systems that might carry sparks to distant combustibles should be suitably protected or shut down [3].
• When welding near combustible walls, partitions, ceilings, or roofs, provide fire-resistant shields or guards to prevent ignition [3].
• If welding on a metal wall, partition, ceiling, or roof, take precautions to prevent ignition of combustibles on the other side, preferably by relocating combustibles. If combustibles cannot be relocated, provide a fire watch on the opposite side of the work [3].
• A fully charged fire extinguisher must be available at all times during welding [4].

2. Personal Protective Equipment (PPE):

• Welders need to wear protective clothing appropriate for welding and use protective equipment for the welding job [4].
• Use helmets or hand shields during all arc welding or arc cutting operations, excluding submerged arc welding. Goggles should also be worn during arc welding or cutting operations to provide protection from injurious rays from adjacent work and from flying objects [5].
• For overhead welding and cutting, or welding and cutting in extremely confined spaces, ear protection is sometimes desirable [6].
• Where there is exposure to sharp or heavy falling objects, or a hazard of bumping in confined spaces, hard hats or head protectors must be used [6].

3. Ventilation and Air Quality:

• Welding work should be performed in well-ventilated areas 9, 20.
• Adequately vent all welding and cutting operations carried on in confined spaces to prevent the accumulation of toxic materials or possible oxygen deficiency [7]. All air replacing that withdrawn must be clean and respirable [7].
• In confined spaces, if it is not possible to provide such ventilation, use airline respirators or hose masks approved for this purpose by NIOSH [7].
• Provide mechanical ventilation when welding or cutting is done in a space of less than 10,000 cubic feet per welder, in a room having a ceiling height of less than 16 feet, or in confined spaces [8].
• Ensure that the amount of toxic fumes, gases, or dusts are below the maximum allowable concentration [9].

4. Electrical Safety:

• Turn the starter key switch to the "OFF" position and wait 4 seconds for electrical power to disconnect [10].
• Remove the negative (-) cable from the battery terminal 6, 9, 20.
• Attach the welder ground cable with 1 m {3'3"} away from the component being welded 6, 9.
• Make sure the welder ground is not located at a seal or bearing and that no bearings or seals separate the welder ground and the weld area 6, 9, 20.
• Check grounding of the welding machine frame and give special attention to safety ground connections of portable machines [11].
• Spread coiled welding cable out before use to avoid serious overheating and damage to insulation [11].
• Place electrode holders when not in use so that they cannot make electrical contact with persons, conducting objects, fuel, or compressed gas tanks [11].

5. Confined Spaces:

• Ventilation is a prerequisite to work in confined spaces [6].
• When welding or cutting is being performed in any confined spaces, gas cylinders and welding machines must be left on the outside [6].
• Where a welder must enter a confined space through a manhole or other small opening, provide means for quickly removing the welder in case of emergency. An attendant with a preplanned rescue procedure must be stationed outside to observe the welder at all times and be capable of putting rescue operations into effect [6].
• When arc welding is to be suspended for any substantial period of time, remove all electrodes from the holders and carefully locate the holders so that accidental contact cannot occur and the machine is disconnected from the power source 1, 3.
• When gas welding or cutting, close the torch valves and positively shut off the fuel-gas and oxygen supply to the torch at some point outside the confined area whenever the torch is not to be used for a substantial period of time 1, 3.

6. Cylinder Safety:

• Compressed or liquefied gas cylinders must be secured, preferably upright, and cannot fall or roll [1].
• Ensure that sparks, flames, or other sources of ignition are not allowed to come in contact with the cylinders, regulators, or hoses of a compressed or liquefied gas system [1].
• When gas welding or cutting, close the torch valves and positively shut off the fuel-gas and oxygen supply to the torch at some point outside the confined area whenever the torch is not to be used for a substantial period of time [6].

7. Equipment Maintenance:

• Workers assigned to operate or maintain arc welding equipment must be acquainted with the relevant safety requirements [11].
• Before starting operations, check all connections to the machine to make certain they are properly made. Firmly attach the work lead to the work and free magnetic work clamps from adherent metal particles of spatter on contact surfaces [11].
• Check for leaks of cooling water, shielding gas, or engine fuel [11].
• Determine that proper switching equipment for shutting down the machine is provided [11].
• Strictly follow printed rules and instructions covering the operation of equipment supplied by the manufacturers [11].

8. Specific Materials:

• In confined spaces, welding or cutting involving fluxes, coverings, or other materials that contain fluorine compounds must be performed in accordance with specific ventilation requirements [12].
• In confined spaces, welding or cutting involving zinc-bearing base or filler metals or metals coated with zinc-bearing materials must be performed in accordance with specific ventilation requirements [12].
• In confined spaces, welding involving lead-base metals must be performed in accordance with specific ventilation requirements. When welding or cutting operations involve metals containing lead, use local exhaust ventilation or airline respirators [12].

9. General Precautions:

• Always release the internal pressure of the hydraulic tank before performing inspection or maintenance procedures [10].
• Clear flammable items and provide a fire extinguisher [4].
• Remove paint from any surface to be welded. Painted surfaces produce unhealthy gases when welded 9, 20.
• After welding operations are completed, mark the hot metal or provide some other means of warning other workers [6].
• Management must establish areas for cutting and welding and establish procedures for cutting and welding in other areas [3].
• The supervisor must be responsible for the safe handling of the cutting or welding equipment and the safe use of the cutting or welding process [3].

By integrating these measures into a JHA, employers can systematically identify and mitigate hazards associated with welding tasks, promoting a safer working environment.