Metal welding safety. Guidance Note. Practical advice for employers on controlling hazards when welding. June Background. How to use the table

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1 Guidance Note Metal welding safety Practical advice for employers on controlling hazards when welding. June 2011 Background Metal welding involves the application of heat to join two metals together. The heat is generated through electric currents (arc welding) or gases (gas welding). Welding is undertaken in many industries for purposes including the manufacture of machinery, tools and equipment and repair and maintenance work. Those most at risk of welding-related injuries are operators producing industrial or commercial machinery and fabricated metal products. How to use the table The table over the page lists and shows examples of the main hazards related to welding. It also includes the possible consequences of the hazard and provides a list of recommended controls. The zone numbers in the table refer to what is shown in the picture below. Main hazards The most common causes of injury from welding result from: manual handling fire, explosions and radiation exposure electric shock. Employers must provide a safe work environment for workers by implementing adequate controls for all identified workplace hazards Zone 1: Welding equipment Zone 2: The welding process Zone 3: Work pieces being welded Zone 4: Welding with gases Zone 5: The operator Zone 6: Welding workspace Note: This guidance note does not include information on welding in confined spaces or under water. GUI0145/01/

2 Zone 1: Welding equipment Welding equipment (body, hoses and hand gun) is worn, damaged or poorly maintained. Welding leads and hoses are not uncoiled before use. Worn or damaged electrical leads, power points and extension cords. The open circuit voltage is not reduced to a safe level. Welding currents are not grounded. Welding equipment can fail. Failure of hoses and fittings allows gas to escape resulting in a fire or explosion. Damaged electrical components can result in electric shocks to the operator. High currents passing through coiled leads can result in damage from heat increasing the risk of electric shock. Electrical faults can cause electric shock or, where they interact with flammable substances, burns. Operator receives an electric shock. Operator receives an electric shock. Regularly inspect and maintain welding equipment (including the insulation). Repair or discard damaged or worn parts (giving consideration to decommissioning processes). Store welding equipment where it cannot be damaged (particularly for portable or mobile oxy-fuel gas welding). Completely uncoil welding leads before use. Use cables that are appropriate for the current being carried. Maintain leads, power points and extension cords in good working condition. Ensure installation and servicing of electrical supply circuits is done by a qualified electrician. Regularly inspect insulation on cords and remove damaged cords from use. Ensure the open circuit voltage is within safe limits and, where necessary, use voltage limiting devices (VLDs). Ensure proper grounding methods have been applied within the welding area and they are in good working order. Zone 2: The welding process Lack of familiarity with the gases used or fumes produced during welding processes. Exposure to welding arc. Workers can become ill if dangerous fumes are not removed from the workplace. Operators can experience burns to skin and eyes from radiation (ultraviolet and infrared). Ensure familiarity with materials being used (such as gases, base metals, coatings and cleaners) and their possible health impact. Where necessary, engage a suitably qualified person such as an industrial hygienist to assist. Wear auto darkening helmets. Carry out welding processes in booths or use welding screens to protect nearby workers. 2

3 Fumes produced during welding processes. Workers can experience eye, skin and respiratory system irritation, nausea, headaches and dizziness. Dust and fumes can cause serious lung diseases and increase the risk of asthma and cancer and possibly lead to asphyxiation. Ensure fumes and gases are removed from the breathing zone. Eg. Ventilation. General ventilation When used by itself, ensure general ventilation removes welding fumes from the breathing zone (including on days with little wind). Mechanical ventilation Ensure the speed of the systems is great enough to draw fumes out of the breathing zone. Where the fumes are drawn downward, ensure work pieces do not cover too much of the ducting or the exhaust effect will be lost. Ensure mechanical ventilation removes fumes close to the source. Flexible ducting allows the capture device to be moved to the appropriate position (see picture). Ensure that fumes drawn outside are not able to re-enter the workplace. Ensure mechanical ventilation units are maintained in good working order. Undertake health surveillance to monitor workplace exposure to hazardous substances. Zone 3: Work pieces being welded Welding objects or plant that contain/have contained (with traces remaining) flammable or explosive substances or gases. Object being welded can explode or create a fire resulting in fatalities, burns or fractures to operator or nearby workers. Ensure welding activity is not performed on objects or plant in which a flammable substance has been manufactured, used, handled or stored unless it is completely free of the substance or gas. If the contents of the object or plant are unknown, it should be assumed that it contains flammable or explosive substances. 3

4 Welding objects are coated in unidentified paints or metal coatings. Pieces of slag or molten metal come away from work pieces and make contact with leads and hoses. Dangerous fumes can be generated when welding some coatings. This can cause respiratory distress, eye or skin irritations, headaches or nausea. Operators can receive an electric shock or an explosion can occur. Identify coatings on work pieces before commencing work and take actions to prevent exposure to dangerous fumes (this will vary depending on the coating). Where possible, elevate cables, hoses and wires. For example, suspend them on hangers or swing arms. Zone 4: Welding with gases Flames travel back down the gas hoses (known as flashback). Movement of heavy gas cylinders. Flashback can cause explosions and fires, burning the operator. Regular movement or replacement of gas cylinders requires awkward postures and high forces and may cause muscle sprains and strains. Ensure hoses are fitted with flashback arrestors at both ends. Consider piping gases into the building near workstations to eliminate the need for operators to manually handle cylinders (see picture). Gases are stored with incompatible chemicals or in inappropriate locations. Gases may explode injuring operators and nearby workers. Use mechanical aids to move cylinders. Consider using gases that require less frequent replacement. For example, LPG lasts longer than acetylene. Store gases in accordance with their classification and quantities (refer to the Australian Dangerous Goods Code). Store gas cylinders in well ventilated areas and protected from weather but not at the expense of ventilation. 4

5 Gas cylinders are not secured in location. If a cylinder falls over the valve at the top can be knocked off causing the cylinder to become a dangerous projectile that can strike and injure operators. Workers can also inhale the escaping gases which can damage the respiratory system or cause asphyxiation. Store gas cylinders in a safe location that is protected from the immediate welding area. Secure cylinders using gas cylinder holders or anchored chains to prevent tipping over (see picture). Zone 5: The operator Operators are inexperienced (eg apprentices, trainees and young workers) or not trained to perform welding safely. Lack of or inappropriate supervision. Welding is performed on the ground or requires awkward positions. Inexperienced or poorly trained operators are more likely to make mistakes increasing risk of injury. Unsupervised operators are at greater risk due to unsafe work practices. Awkward postures can result in muscular sprains and strains or fatigue. Ensure operators demonstrate competency and hold an appropriate certificate or have had required training or experience. Ensure operators are adequately supervised by a certified welding supervisor. Position work piece in the best working zone, between the shoulders and knees (eg using height adjustable benches or supports). Low risk Medium risk High risk 5

6 Manual movement of heavy materials and work pieces. Electrodes or welding wire are touched with bare hands when in the holder or welding gun. Holding welding gun under the armpit. Repetitive squeezing of welding handles or triggers. Lack of, inappropriate or damaged personal protective equipment (PPE) or respiratory protective equipment (RPE) worn by operator and nearby workers. Operator can experience muscular sprains and strains or fatigue. Operator will receive an electric shock if these are touched with bare skin. Electric shock (sweating increases conductivity). Operators can experience strains from frequently performing the same task. Cracked or damaged helmets or inappropriate filters can expose operators to radiation causing eye damage. Synthetic clothing can easily catch fire. Molten metal and sparks can enter pockets and cuffs or make contact with bare hands resulting in burns. Dust and fumes can cause serious lung diseases increasing the risk of asthma and lung cancers. Design the work environment so that excessive physical effort is not required to move materials. Eg use mechanical aids or adjustable rotator or fixture (jigs) to align parts. Ensure electrodes and welding wire in their holder or the welding guns are never touched with bare hands. Never hold welding guns under the armpit. Automate the welding process or reorganise work practices to eliminate exposure. Ensure operators are provided with and use task appropriate PPE and RPE that is in good condition. Ensure workers are trained on how to correctly use their PPE and RPE. Store PPE close to workstations where it can t be damaged or contaminated. Ensure operators wear: task appropriate auto darkening helmets fire resistant protective clothing, such as raw hide operators jacket, cotton heat vests and long cuff welding gloves/gauntlets insulating gloves rubber soled boots designed for welding tasks securely fitting RPE where RPE is assessed as necessary. Zone 6: Welding workspace Welding in a non-designated area. Welding in an uncontrolled open air environment. Open flames and sparks from welding can ignite flammable substances produced from work nearby causing burns or fractures to workers. Changes in weather can cause an explosion if gases travel into areas with an ignition source. Operators can receive an electric shock if welding equipment gets wet. Where possible, set up designated welding areas. Ensure a competent and experienced person has undertaken a hot work permit prior to commencing welding processes. Assess the environment where the welding is to be done before work starts and if necessary change the location. Make sure welding area and equipment is dry before work starts. Never weld near incompatible substances (including where they are stored). 6

7 Welding near flammable substances or materials. This includes objects, machinery or equipment that contain, or has contained flammable substances, or in areas containing dusts, grains, or paperwork. Workspace is untidy. For example, cables running across the floor and waste not regularly removed. Substances near the object being welded can explode or catch fire, or welding sparks can ignite materials or dust in the work area resulting in burns or fractures. Workers can trip over objects (cables, work materials) or slip on spills. Never weld near flammable substances such as those in objects, machinery or equipment unless they are rendered free of the substance. Remove flammable or toxic materials from the welding area before work is carried out. Inspect and clean work areas regularly. Organise the work areas to minimise the number of cables and position them where they cannot be stepped or tripped on. Eg suspend hoses off the ground (see picture) or coil hoses when not in use. Consider installing hoses and cables underground. Use boom-mounted wire feeders to eliminate the lifting of feeders and cable cutter off ground (see picture). Regularly clean work areas to reduce clutter and prevent the build up of flammable materials including dust. 7

8 Welding on wet or poorly insulated floor. Excessive noise from welding processes Lack of, or poorly maintained, emergency management plan and emergency equipment (including lack of training on how to use it). Operator can receive an electric shock. Operator and nearby workers can suffer hearing loss. Operators cannot effectively respond in emergency situation such as explosions or fire, and will receive burns or fatal injuries. Where possible, work should be performed on dry insulated surfaces such as wooden platforms or insulating mats. Where possible, control noise at the source. Provide operators with appropriate hearing protection for the level of noise exposure. Where necessary, undertake audiometric testing of both the work area and operators and put controls in place. Ensure the workplace has fire safety equipment such as alarm systems, fire extinguishers, hydrants, hoses and fire blankets. Regularly inspect and test fire safety equipment as per equipment requirements. Have an emergency plan in place. Ensure workers have been trained in emergency procedures. Further information and guidance Contact the WorkSafe Victoria Advisory Service on or go to worksafe.vic.gov.au Related WorkSafe publications A guide to safety in the metal fabrication industry Metal Fabrication Improving health and safety through layout and design AS Safety in welding and allied processes. Part 1: Fire precautions AS Safety in welding and allied processes. Part 2: Electrical Australian Dangerous Goods Code Note: This guidance material has been prepared using the best information available to the Victorian WorkCover Authority, and should be used for general use only. Any information about legislative obligations or responsibilities included in this material is only applicable to the circumstances described in the material. You should always check the legislation referred to in this material and make your own judgement about what action you may need to take to ensure you have complied with the law. Accordingly, the Victorian WorkCover Authority cannot be held responsible and extends no warranties as to the suitability of the information for your specific circumstances; or actions taken by third parties as a result of information contained in the guidance material. 8