Welding hazards and the risk process

A welding shop’s hazards are easy to list and hard to manage. Everyone knows the arc is bright, the metal is hot and the fume is unpleasant. What is less obvious is which hazards cause the most harm in a particular shop, which ones cause harm that shows only years later, which controls actually work, and how to tell whether they are working. Generic procedures, copied from a template and filed in a folder, rarely answer those questions. A programme built on the shop’s own work, its own measurements and its own injury record does.

This chapter lists the hazards of welding and cutting, separates those that harm immediately from those that harm slowly, sets out the risk management process the work health and safety laws expect and the hierarchy of control that ranks the ways of managing a hazard, and shows how the running case’s coordinator used the shop’s injury record to decide where to begin.

The hazards

Figure 1Hazards of welding and cutting

	Source	Harm	When it shows
Fume and gases	metal particles, oxides and gases from the arc, flame, coatings and consumables	irritation, metal fume fever; lung disease; cancer	hours to decades
Radiation	ultraviolet, visible and infrared light from the arc and flame	arc eye; skin burns; eye damage; skin cancer	hours to years
Electricity	welding circuit and mains supply	shock, falls from shock, burns, death	immediately
Heat, sparks and fire	hot metal, spatter, slag, flames	burns; fires and explosions	immediately
Compressed and flammable gases	cylinders, hoses, fuel gases, shielding gases	fire, explosion, asphyxiation in confined spaces	immediately
Noise	arc, gouging, grinding, hammering	hearing loss, tinnitus	years
Manual handling and posture	heavy work, awkward positions, repetition	strains, back and shoulder injury	days to years
Heat stress	hot work in leathers, hot weather	heat illness	hours

The list divides into two groups that need quite different management. Burns, shocks, fires, cuts and arc eye happen immediately and visibly; the injured person knows at once, and the injury appears in the shop’s records. Lung disease, cancer, hearing loss and long-term musculoskeletal damage develop slowly, often over years, and by the time they appear the exposure that caused them is long past, often in another job. The immediate hazards dominate the injury record; the delayed ones may dominate the harm. A programme that manages only what appears in the injury record will miss much of what matters most.

The risk management process

The work health and safety laws in each Australian jurisdiction place a duty on the business to eliminate risks to health and safety so far as is reasonably practicable, and if a risk cannot be eliminated, to minimise it so far as is reasonably practicable. Safe Work Australia’s model codes describe a process for doing so.

Figure 2The risk management process applied to welding

1. 1Identify hazardswalk the shop; list each process, material, coating, location and task
2. 2Assess riskshow likely harm is and how severe; measure exposures where they can be measured
3. 3Control riskschoose controls by the hierarchy of control; put them in place
4. 4Review controlscheck that they work, by inspection, measurement and the record; revise when things change

The process is continuous, not a one-off exercise completed for an audit and then forgotten. New work, a new process, a change of consumable, a new building or an incident all start it again for the hazards they affect. Workers must be consulted throughout, because they know the work and the shortcuts, and because controls they helped design are far more likely to be used.

The hierarchy of control

Controls are not equally effective. The hierarchy of control ranks them, from those that remove the hazard to those that rely on people doing the right thing every time.

Figure 3The hierarchy of control with welding examples

	What it does	Welding examples
Elimination	removes the hazard altogether	bolt instead of weld; buy parts pre-fabricated; remove coatings away from welding
Substitution	replaces it with something less hazardous	lower-fume process or consumable; non-coated steel; plasma gouging instead of arc-air
Engineering controls	isolates people from the hazard	local exhaust ventilation; screens; positioners; voltage-reduction devices
Administrative controls	changes how work is done	permits; procedures; job rotation; training; signage
Personal protective equipment	protects the individual	helmets and filters; respirators; leathers; hearing protection

In welding, personal protective equipment is always needed, because the welder cannot be completely separated from the arc. But it is the last line of defence, not the first. A welder wearing a respirator in a shop with no extraction is protected only while the respirator fits, is worn and is in good condition, and everyone else in the shop breathes the fume. Extraction at the arc protects everyone, all the time. The hierarchy’s lesson is to work down it, using each level as far as is reasonably practicable before relying on the next.

Assessing risk with numbers

Many workplaces rate risks on a matrix of likelihood against consequence, giving each hazard a rating that sets its priority. The ratings are useful for ranking, but they are judgements. Where a hazard can be measured, measurement is far better: an exposure to fume, measured in the welder’s breathing zone, compared with the exposure standard; a noise level, measured at the ear, turned into a daily dose; an extraction hood’s capture velocity, measured at the point of welding. Measured hazards can be compared with standards, ranked by how far they exceed them, and checked again after controls are put in place to see whether the controls worked. The following chapters show how.

Materials that change the hazard

The same welding process can be far more hazardous on one material than another, because the material and anything on its surface end up in the fume. Galvanised steel’s zinc coating vaporises at the arc and causes metal fume fever, a flu-like illness that follows heavy exposure. Stainless steel’s chromium forms hexavalent chromium in the fume, a recognised cause of lung cancer, and its nickel is also a concern. Manganese, present in most steel consumables and at high levels in hardfacing and manganese steel electrodes, can damage the nervous system with prolonged exposure. Old paints may contain lead; some plated parts carry cadmium; oil, grease and some degreasing solvents decompose in the arc, and chlorinated solvents near the arc can form highly toxic phosgene. The hazard identification for each task therefore asks not only which process, but which base metal, which consumable and which coating, and the safety data sheets for consumables are read, not just filed.

Reasonably practicable

The duty is to eliminate or minimise risks so far as is reasonably practicable, which means doing what is reasonably able to be done, weighing the likelihood and severity of harm, what is known about the hazard and the ways of controlling it, the availability and suitability of those ways, and, only after all of that, the cost. Cost can justify not adopting a control only where it is grossly disproportionate to the risk. For welding fume, where the hazard is serious, well understood and controllable with readily available extraction, it is rarely reasonable to rely on respirators alone or to accept exposures above the standard because extraction would cost money. The coordinator’s business cases for extraction were written to show the risk first and the cost second.

The risk register

The results of the process are recorded in a risk register: each task or area, its hazards, the assessed risk, the controls in place, any measurements, the person responsible and the date of the next review. The register is short enough to be used, specific enough to match the shop, and reviewed whenever the work changes. The coordinator replaced the bought folder’s forty pages with a register of about sixty lines, one for each combination of process, material and location the shop actually used, each linked to the measurement or inspection that showed whether its controls worked.

When the work changes

Most serious incidents in welding shops happen when something is different: a new contract with a different material, a repair inside a tank, a rush job worked late with tired people, a new worker who has not been shown the extraction, a piece of equipment brought in from another site. The risk process is meant to be run again at each such change, and the coordinator added a simple trigger to the shop’s job planning: any job involving a new material or coating, a confined or enclosed space, work at height, work outside the shop or an unfamiliar process gets a short, documented risk assessment by the supervisor and the welders before it starts.

Health as well as safety

The duty covers health as well as safety, and the delayed hazards of welding are mostly health hazards. Managing them means measuring exposures, controlling them at the source, and, where the regulations require or the risk warrants, monitoring the health of exposed workers, as Chapter 10 describes. It also means recognising that some harm, such as a cancer caused by welding fume, may appear long after a worker has left the shop, so the records of exposures and controls are kept for the periods the regulations require.

The shop’s injury record

An injury record does not show everything, as the delayed hazards remind us, but it does show the immediate hazards clearly, and it is the place most shops start.

Figure 4Injuries recorded in the shop over three years, by type

Eye injuries: arc eye and foreign bodies14 number of recorded injuries

Burns11 number of recorded injuries

Cuts and lacerations9 number of recorded injuries

Strains and sprains8 number of recorded injuries

Other4 number of recorded injuries

Eye injuries headed the record, made up of arc eye, mostly among workers near welding rather than the welders themselves, and particles in the eye from grinding and chipping. Burns came next, mostly from spatter entering gaps in clothing and from picking up hot work. The coordinator’s first actions followed: screens between welding bays and walkways, safety glasses for everyone on the shop floor at all times, a rule that grinding and chipping be done with face shields over glasses, and fire-resistant clothing without gaps at the neck and cuffs. Within a year, eye injuries had fallen from an average of nearly five a year to two, and burns from nearly four a year to one, and the committee kept watching both figures closely in case the improvement faded once the changes were no longer new.

Looking beyond the record

The coordinator also commissioned measurements of what the record could not show: fume exposures for welders on each main process, noise levels at the welding, grinding and gouging stations, and the extraction systems’ performance. Those measurements, described in later chapters, showed fume exposures above the exposure standard for some welders on flux-cored work in enclosed areas, and noise levels that made hearing protection essential at the grinding stations. Neither had appeared in three years of injury records.

Consultation

The work health and safety laws require consultation with workers on matters that affect their health and safety, including identifying hazards and deciding on controls. The coordinator set up a small health and safety committee with three welders, a supervisor and the coordinator, which walked the shop each month, reviewed the measurements and incidents, and proposed controls. The welders’ knowledge of the work was decisive: it was a welder who pointed out that the fume extraction arms were too short to reach the far end of the larger jigs, so welders simply did not use them there.

Contractors and visitors

A shop’s duty extends to everyone at the workplace: contractors who install or repair equipment, delivery drivers, visitors and customers inspecting work. Arc eye among people walking past welding bays was a large part of the running case’s eye injuries. Screens, marked walkways, safety glasses at the entrance and an induction for contractors that covers the welding hazards protect people who do not weld and may not know what the arc can do.

The running case: the first year’s plan

This is an illustration. The coordinator’s first-year plan ranked the shop’s hazards by their measured or recorded risk and by how practicable the controls were: screens and eye protection first, because they were quick and the injuries were frequent; extraction improvements second, because the fume measurements showed exposures above the standard; noise controls and hearing protection third; a review of electrical equipment, gas cylinders and hot work permits fourth; and an ergonomic review of the larger jigs fifth. Each item had an owner, a date and a measure of success, and the committee reviewed progress monthly.

A failure: the folder

This is an illustration. Before the coordinator’s appointment, the shop’s safety system had been a folder of procedures bought from a consultant, covering every welding hazard in general terms. It had been signed by every worker at induction and never opened since. It required fume extraction to be used, but did not say where the extraction was or whether it worked; it required eye protection, but not for people walking past.

An inspector from the regulator, visiting after a burn injury, found the procedures did not match the work and that no exposures had ever been measured. The improvement notice that followed was what led to the coordinator’s appointment.

Exercise: ranking two controls

Fume measurements show that welders in an enclosed bay are exposed to about three times the exposure standard while welding. One option is to issue powered air-purifying respirators to the bay’s four welders, at about A$2,000 each plus A$400 a year each in filters and maintenance. Another is to install local exhaust ventilation at the four stations, at about A$24,000 installed and A$1,500 a year to run and maintain, which trials show would bring exposures below the standard without respirators. Which does the hierarchy of control favour, and what do the costs look like over five years?

The hierarchy favours local exhaust ventilation, an engineering control that reduces the fume for everyone in the bay, all the time, without depending on each welder wearing and maintaining a respirator correctly.

Over five years, the respirators cost about 4 × 2,000 + 5 × 4 × 400 = A$16,000, and the extraction about 24,000 + 5 × 1,500 = A$31,500. The extraction costs more, but it protects the welders’ helpers and passers-by as well, and does not fail when a respirator is worn poorly or left on the bench. Respirators may still be needed for tasks the extraction cannot reach, but as a supplement, not the main control.