Welding - Health and Safety in
Part 15: Radiation (Ultraviolet, Infrared and Lasers)
Hazards of ultraviolet radiation from arc flash can affect both the eyes and skin and are covered elsewhere in this booklet.
The skin has its own warning mechanism for thermal radiation but the eyes do not. When exposed to heat, the eyes should be protected. See AS/NZS 1338.1:1992 Filters for eye protectors - Filters for protection against radiation generated in welding and allied operations.
The safety of laser cutting/welding processes will require specialist advice both in terms of the safe use of the equipment and personal protection.
See AS/NZS ISO 11553:2004 Safety of machinery - Laser processing machines - Safety requirements and the AS/NZS 2211 series on laser safety.
Part 16: Working Technique
Keeping the head out of the welding plume is an essential element of welding safety, as is good housekeeping.
Part 17: Noise and Vibration
Noise
Noise levels can be hazardous during some welding and metal cleaning processes.
The Department of Labour Approved Code of Practice for the Management of Noise in the Workplace should be followed to identify noise sources, assess their significance and apply control measures.
TN7 refers to Australian noise control practices, and should not be referred to for methods of noise assessment, as the New Zealand methods are different.
Audiometry will be required where employees are exposed to hazardous levels of noise to ensure that hearing is not damaged by exposure to it.
Vibration
The prolonged use of powered hand tools may expose welders to harmful levels of vibration, resulting in decreased blood circulation in the fingers. The effect of vibration is exacerbated when working in the cold. Vibration exposure can be reduced by:
- selecting the appropriate tool
- selecting a tool designed with ergonomic principles in mind
- regular maintenance
- wearing gloves.
Part 18: Manual Handling
Some welding tasks can involve heavy and/or repetitive manual handling or work with sustained awkward postures for long periods without a break.
The joint Department of Labour/ACC Code of Practice for Manual Handling should be used to identify hazards in manual handling tasks, assess their significance and devise controls.
Part 19: Hand Tool Fitness and Safety
Hand tools used during metal preparation and weld treatment can pose several types of hazard:
- hand tools can create sparks and ignite some welding gases
- electrically-powered tools (grinders) pose the risk of electric shock - check electrical safety regularly and use RCDs
- tools used for deslagging, grinding and chipping may pose hazards to the eyes - wear eye protection
- prolonged use of poorly maintained power hand tools can result in injuries from vibration
- the physical design of hand tools (if not based on ergonomic principles) can pose the risk of a musculoskeletal disorder. Relevant factors are tool weight, trigger design, grip/handle diameter and tool shape
- air-powered tools can discharge cold air over the hands
- using tools with wet/sweaty hands may compromise electrical safety and/or cause the hands to slip
- ensure any electrical or heat insulation on the tool handle remains intact
- grinding wheel hazards - safety principles must be adhered to.
See Occupational Overuse Syndrome (OOS) - Checklists for the Evaluation of Work
Part 20: Specific Requirements of the Health and Safety in Employment Act 1992
The Health and Safety in Employment (HSE) Act 1992 requires employers to take all the practicable steps open to them in the circumstances to prevent harm occurring to employees. This requirement is covered in the sections above and in TN7 and the Fume Minimisation Guidelines.
The HSE Act places some additional obligations on employers, including the requirements to:
- provide information, training and supervision to employees
- pay for protective equipment - in a range of circumstances
- when employees are exposed to significant hazards, to carry out (with each employee's informed consent) health monitoring
- involve employees in health and safety matters.
Information, Training and Supervision
Basics are covered previously in this booklet. TN7, equipment suppliers and experienced welders may be consulted for more information.
Information should be given in a manner the employee can understand and cover the items in this booklet plus what to do in emergency situations, (fire, explosion, electrocution, confined space collapse, burns, eye injuries and exposure to fumes).
Training should cover the right way to do the task, the hazards in it, how to prevent hazards causing harm, incident/damage reporting procedures and how to use PPE.
Supervision should continue until a welder is competent, and will always be required in some situations, such as confined space entry.
Monitoring
Environmental Monitoring
This may be required to assess the level of exposure to welding fumes, to monitor exposure to gases such as ozone or nitrogen oxides produced during certain welding processes or to monitor oxygen content or the build up of explosive gases in confined spaces.
Personal Health Monitoring
This must be carried out, with the person's informed consent, if they are faced with a significant hazard. The decision as to whether a significant hazard is faced rests with the employer.
Hearing, vision and lung function testing are typically monitored in welders. Biological monitoring to establish the absorption of substances such as lead or manganese will be appropriate if welders are exposed to these substances.
Exposure to welding fumes has been shown to cause a number of respiratory conditions, including fume fever, chemical pneumonitis, reversible bronchospasm and occupational asthma.
Biological monitoring may be necessary to follow the health of people exposed to welding fumes. See www.cdhb.govt.nz/chlabs/testsframe.htm.
Respiratory conditions arising as a consequence of welding fume exposure are best monitored by the following:
- a respiratory questionnaire given to the exposed employees and either self-administered or administered by an occupational health nurse.
- the use of serial peak flows. Peak flows measure the amount of air forcibly expelled from the lungs in one second. Various values or patterns are evident when the lungs are not functioning properly
- a peak flow meter is required (available from the occupational health nurse) and the recordings are usually done for a period of time at work and away from work (to give normal values)
- the Department of Labour recommends recording the best of three blows, repeated four times a day (before work, in the middle of work, at the end of work and as the person goes to bed at night) for two weeks, with some period of this two weeks being away from work.
- if the respiratory questionnaire or the peak flow recordings suggest a problem then more specific lung function testing and x-rays may be appropriate. This would be undertaken at the discretion of the investigating doctor or occupational health nurse (under the advice of the treating doctor).
Employee Participation
Employees must be involved in the development of health and safety procedures.
Part 21: Welding Fume Control Summary Worksheet
This worksheet can be used to obtain an idea of the level of protection required for different welding processes.
A. Select a process weighting factor
| Process | Weighting |
|---|---|
| Submerged arc welding
(remote operation) Laser cutting and welding Micro plasma Gas cutting (remote operation) |
0 |
| Submerged arc welding (manual) Submerged arc welding (multi arcs) |
2 |
| Brazing (manual operation) Gas tungsten arc welding (TIG) (manual operation) Gas welding and cutting (manual) Silver soldering (manual) Resistance spot welding (manual) Plasma cutting (under water table) Plasma arc welding Gas metal arc welding (MIG) (remote operation) Resistance seam welding (remote operation) Electroslag welding |
4 |
| MIG (hand-held) Manual metal arc welding (MMAW) Resistance seam welding (manual operation) Thermit welding Electrogas welding |
7 |
| Arc cutting Plasma arc gouging Air arc gouging Flux cored arc welding (manual and remote operation) |
9 |
| Plasma arc cutting | 15 |
B. Select a fume constituent weighting
| Fume group | Weighting |
|---|---|
| A Iron, aluminium, tin, titanium - less than 5% of group B or C or less than 0.05% of group D. |
0 |
| B Copper, magnesium, manganese, molybdenum, silver, tungsten, zinc. Flux fumes such as fluorides, rosin, phosphor acid, zinc chloride and boric acid. |
10 |
| C Barium, chromium, cobalt, lead, nickel, ozone, vanadium, phosgene, organic fume. |
20 |
| D Beryllium, cadmium. |
55 |
C. Select a work location weighting
| Work location | Weighting |
|---|---|
| Outdoor workspace | 0 |
| Open workspace | 12 |
| Limited workspace | 16 |
| Confined workspace | 24 |
D. Add the three weightings you obtain at A, B and C to determine the control actions needed as below:
| Sum of weighting factors | Controls |
|---|---|
| ≤ 9 | Natural ventilation |
| > 9 to 21 | Mechanical ventilation |
| > 21 to 54 | Local exhaust ventilation |
| > 54 | Local exhaust ventilation and respiratory protection |
