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1. 1 Please read this before using presentation This presentation is based on content presented at the 2008 Mines Safety Roadshow held in October 2008 It is made available for non-commercial use (e.g. toolbox meetings) subject to the condition that the PowerPoint file is not altered without permission from Resources Safety Supporting resources, such as brochures and posters, are available from Resources Safety For resources, information or clarification, please contact: [email protected] or visit www.docep.wa.gov.au/ResourcesSafety

2. Toolbox presentation: Arc welding hazards and safeguards – fumes and gases

3. Electric arc welding

4. Welding hazards Electric shock Radiation Burns Heat stress Fire Explosions Asphyxiation Fumes and gases These are some of the main hazards associated with welding. This presentation will look closely at fumes and briefly at gases. These are some of the main hazards associated with welding. This presentation will look closely at fumes and briefly at gases.

5. Hazards of fumes and gases What do you know about … your welding processes? composition of the fumes you work in? how well you are being protected from any toxic effects?

6. Fumes and gases produced by welding All types of welding will produce metal fumes Shield metal arc welding (SMAW) and manual metal arc welding (MMAW) Fumes Gas metal arc welding (GMAW) and metal inert gas (MIG) Ozone Carbon monoxide and other gases (depending on shielding gas used) Gas tungsten arc welding (GTAW) and tungsten inert gas (TIG) Ozone Carbon monoxide and other gases (depending on shielding gas used) UV radiation (more produced than in SMAW) Plasma arc welding (PAW) Gases Flux cored arc welding (FCAW) Fumes Quick overview of range of welding types and where fumes and gases featureQuick overview of range of welding types and where fumes and gases feature

7. Metal composition Stainless steel contains: iron nickel chromium manganese Mild (carbon) steel contains: iron generally contains more manganese than other metals These metals contain other elements. The ones mentioned above are ones that are in high concentrations and/or quite dangerous to health. These metals contain other elements. The ones mentioned above are ones that are in high concentrations and/or quite dangerous to health.

8. CONTAM database statistics 23% of people exposed to welding fumes exceed adjusted exposure standard (ES, based on 8 hr shift) 43% of samples that exceed the adjusted ES are at least two times over ES According to Journal of Occupational and Environmental Hygiene (2007), 72% of boilermakers exceed ES If shift length is < or > 8hrs, exposure standard must be adjusted If shift length is < or > 8hrs, exposure standard must be adjusted

9. Health effects of welding fumes Metal fume fever Acute flu-like respiratory illness Siderosis Occupational lung disease from inhalation of iron oxide fumes Toxic metal poisoning E.g. cadmium, beryllium Lung cancer Association with stainless steel (chromium and nickel) fumes only ‘Welder’s disease’ Manganism – collection of symptoms resulting from excessive manganese exposure Also called ‘Parkinson’s syndrome’ because it resembles Parkinson’s disease Effects of welding fumes can be long term, with a delayed onset. Therefore, research into occupational illnesses from welding fumes is difficult as it may take decades for symptoms to show. METAL FUME FEVER: quite common among welders. Predominately from over exposure to ZnO often from galvanised steel. Symptoms similar to the flu . Headache, chills, muscle aches, fever, thirst, nausea, gastrointestinal pain. Symptoms usually start several hours after over exposure. May last 6-24hours More likely to occur after time spent away from the job (ie: after weekend or holiday) No long term effects, absorbed and eliminated by body without chronic effects. SIDEROSIS: form of pneumoconiosis Pneumoconiosis is a lung disease caused from the inhalation of dust. Depending on the type of dust, variants of the disease are considered. Other well-known forms of pneumoconiosis are asbestosis, from asbestos dust and silicosis, from crystalline silica dust. LUNG DISEASE: the welding of stainless steel produces chromium and nickel fumes which can lead to lung cancer. Mild steel welding is believed to pose little risk. Studies suggest that welders may experience a 30-40% higher risk of developing lung cancer than the general population WELDERS’ DISEASE Manganese poisoning “manganism” Headache, spasms, leg weakness, psychosis, mental confusion Speech and balance problems Excessive salivation or sweating Manganese-induced parkinsonism Research has found that symptoms of Parkinson’s disease develop 15 years earlier in welders than the average populationEffects of welding fumes can be long term, with a delayed onset. Therefore, research into occupational illnesses from welding fumes is difficult as it may take decades for symptoms to show. METAL FUME FEVER: quite common among welders. Predominately from over exposure to ZnO often from galvanised steel. Symptoms similar to the flu . Headache, chills, muscle aches, fever, thirst, nausea, gastrointestinal pain. Symptoms usually start several hours after over exposure. May last 6-24hours More likely to occur after time spent away from the job (ie: after weekend or holiday) No long term effects, absorbed and eliminated by body without chronic effects. SIDEROSIS: form of pneumoconiosis Pneumoconiosis is a lung disease caused from the inhalation of dust. Depending on the type of dust, variants of the disease are considered. Other well-known forms of pneumoconiosis are asbestosis, from asbestos dust and silicosis, from crystalline silica dust. LUNG DISEASE: the welding of stainless steel produces chromium and nickel fumes which can lead to lung cancer. Mild steel welding is believed to pose little risk. Studies suggest that welders may experience a 30-40% higher risk of developing lung cancer than the general population WELDERS’ DISEASE Manganese poisoning “manganism” Headache, spasms, leg weakness, psychosis, mental confusion Speech and balance problems Excessive salivation or sweating Manganese-induced parkinsonism Research has found that symptoms of Parkinson’s disease develop 15 years earlier in welders than the average population

10. Health effects of welding gases Carbon monoxide Affects blood’s ability to carry oxygen Ozone and nitrogen oxides Irritate nose, throat, eyes, ears and lungs Nitrogen oxides can cause fluid in the lungs CO combines with haemoglobin, thereby lowering the O2 carrying capacity of the blood. Therefore, CO exposure is a particular concern for welders with heart disease. Nitrogen oxides are formed in larger quantities if nitrogen used in shielding gas Oxides of nitrogen unlikely to be generated at levels approaching the exposure standards (Journal of Occupational and Environmental Hygiene, 2007) Oxides of nitrogen may be problem with plasma cutting processes using nitrogen additions to shielding gas. (Journal of Occupational and Environmental Hygiene, 2007) Ozone formed in larger quantities when using argon as shielding gas. Ozone= suspected lung carcinogen. According to Journal of Occupational and Environmental Hygiene, 2007, “Most welding processes with visible arc generate levels of ozone which place the welder at some risk of exceeding the exposure standard unless controls are implemented.”CO combines with haemoglobin, thereby lowering the O2 carrying capacity of the blood. Therefore, CO exposure is a particular concern for welders with heart disease. Nitrogen oxides are formed in larger quantities if nitrogen used in shielding gas Oxides of nitrogen unlikely to be generated at levels approaching the exposure standards (Journal of Occupational and Environmental Hygiene, 2007) Oxides of nitrogen may be problem with plasma cutting processes using nitrogen additions to shielding gas. (Journal of Occupational and Environmental Hygiene, 2007) Ozone formed in larger quantities when using argon as shielding gas. Ozone= suspected lung carcinogen. According to Journal of Occupational and Environmental Hygiene, 2007, “Most welding processes with visible arc generate levels of ozone which place the welder at some risk of exceeding the exposure standard unless controls are implemented.”

11. Control measures - elimination Eliminate need for welding Buy new equipment Metal coatings add to the fumes produced Safely remove rust inhibitors, paints, degreasers or other coatings before welding begins (band 20-25 mm to be removed each side of weld line)

12. Control measures - substitution Change welding consumables (main contributor to fumes) Avoid wires, electrodes, fluxes with high concentrations of hazardous substances – nickel, chromium, manganese, cadmium, lead, beryllium Substitute lithium silicate or organic binder for sodium or potassium silicates – reduces hazardous chromium VI content in fumes during stainless steel welding Change welding processes Least to most fumes – SAW, GTAW, GMAW, MMAW, FCAW Change shielding gases Fumes reduced by about 20% when mixture of argon and carbon dioxide used instead of carbon dioxide Decrease voltage Produces less fumes

13. Control measures – engineering Use local exhaust ventilation (LEV) Keep exhaust extractions as close to fume source as reasonably practicable Position duct in line with fumes’ natural direction of movement Effective LEV needs 0.5 m/s minimum air velocity Most gas shields can handle air velocity of 2 m/s around weld zone Fixed installations – side- or down-draft benches, partially or completely enclosed booths Portable installations – movable hoods attached to flexible ducts Fume extractors attached to welding gun – can capture 95% of welding fumes In a good exhaust ventilation system, one LEV duct should be able to be turned on without the others being on. In a good exhaust ventilation system, one LEV duct should be able to be turned on without the others being on.

14. Down draft benches Down draft benches help to prevent fumes from passing through the welder’s breathing zone

15. Enclosed booth Extraction via exhaust system from roof Local exhaust ventilation also needed, to direct plume away from welder’s breathing zone Offer noise protection Extraction via roof means that fumes pass through welder’s breathing zone, if local exhaust ventilation is also implemented, fume can be drawn away from breathing zone by LEV and any fume that remains in booth is then extracted by the extraction system in the booth’s roof. Fully enclosed booths are particularly advised for plasma arc cutting, flux cored arc welding, arc air gouging and other high fume producing processes. Booth offers great protection for others in the workshop from fumes and noise. In this booth, the roof can move across to weld larger items in the booth next to it. Extraction via roof means that fumes pass through welder’s breathing zone, if local exhaust ventilation is also implemented, fume can be drawn away from breathing zone by LEV and any fume that remains in booth is then extracted by the extraction system in the booth’s roof. Fully enclosed booths are particularly advised for plasma arc cutting, flux cored arc welding, arc air gouging and other high fume producing processes. Booth offers great protection for others in the workshop from fumes and noise. In this booth, the roof can move across to weld larger items in the booth next to it.

16. Portable exhaust ventilation Good in circumstances where lots of fumes are produced and extra ventilation is required or where welding does not normally take place, or in confined spaces Good in circumstances where lots of fumes are produced and extra ventilation is required or where welding does not normally take place, or in confined spaces

17. Control measures – engineering (continued) Use general ventilation Must be well designed so clean air flows past workers, contaminated air drawn away from workers Not as effective as local exhaust ventilation Should only be used for low toxicity substances Fans will dilute and help to move fumes along (consider where to!)

18. Control measures - administrative Good work practices can reduce exposure to fumes Keep face out of the line of plume Do not remove face shield until plume has dispersed Remove surface coatings before welding begins Have work clothes washed on-site (restrict spread of contaminants) Reduce duration and frequency of task Limit time any one welder is exposed to high fume concentrations Promote no-smoking policy Smoking increases susceptibility to adverse health effects from welding fumes

19. Control measures – administrative (continued) Training How to recognise harmful substances (metal coatings, degreasers, rust inhibitors) Use of MSDSs to identify presence of metals such as cadmium, nickel, chromium, lead, beryllium and manganese Ways to reduce overall fume production Ways to reduce fume exposure Care and maintenance of PPE Consult with ventilation experts and colleagues Monitor and review processes

20. Control measures – PPE (respiratory) Respirators should be worn during all welding processes Level of respiratory protection required depends on amount of time spent welding toxicity of fumes whether gases may also be present ventilation of work area Protection in accordance with AS/NZS 1715 and AS/NZS 1716 To be effective, respirator must fit welder’s face properly. Facial hair will interfere with the closeness of fit. Expert advice (from hygienists or physicians) may be needed to correctly select respiratory protection so that it can best protect from the hazards associated with the task at hand. To be effective, respirator must fit welder’s face properly. Facial hair will interfere with the closeness of fit. Expert advice (from hygienists or physicians) may be needed to correctly select respiratory protection so that it can best protect from the hazards associated with the task at hand.

21. Control measures – PPE (respiratory) (continued) Class P3 respirator protects against all particulates including highly toxic material (e.g. beryllium, cadmium) Combination of particulate and gas filters may be necessary Welding aluminium, galvanised steel or stainless steel requires added protection (e.g. powered air purifying respirator, additional ventilation) Respirators with one filter to each side fit better under welding shields than respirator with only one filter at the front Additional protection may be required in some circumstances. Check MSDS Additional protection may be required in some circumstances. Check MSDS

22. Powered air purifying respirators

23. Summary of hazards from fumes and gases All welding processes pose a health risk, some more than others Best way to protect yourself from risks is through: avoiding more hazardous substances, where practicable adequate ventilation exhaust systems good work practices being familiar with the materials you are using (read the MSDS) wearing appropriate, well-fitted and maintained PPE Outdoors or open work space: general ventilation Limited work space: local exhaust ventilation Confined space: respirator, local exhaust ventilation, communication strategy, rescue plan If unsure, consult a hygienist and avoid fumes

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