Welding inside barge hopper tank

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# What types of ventilation can be used to remove air contaminants from a welder's breathing zone? (cont.) ## Mechanical Dilution Ventilation (cont.) See the OSH Answers on Industrial Ventilation for more information. ## Local Exhaust Ventilation Local exhaust ventilation (LEV) is always the preferred method of removing welding fumes and gases. It exhausts or removes the toxic gases, fumes, dusts, and vapours before they can mix with the room air. A well-designed welding helmet can help reduce a welder's exposure to welding fumes by diverting the plume away from the welder's breathing zone. ## What are some examples of Local Exhaust Ventilation? ## Downdraft Bench A downdraft bench has an open grid work surface. Air is drawn downward through the grid, drawing contaminants into exhaust ducting. Air speed must be great enough to prevent contaminants from accumulating and rising into the breathing zone. If workpieces are too large, they may block the ventilation airflow or cause pockets of high-velocity air (which could affect shielding gases). Exhaust ducts Cleanout doors Enclose base of table Slotted baffle - size slots for 2000 feet per minute (10 m/s) ## Moveable Hood Flexible ducting allows the capture hood to be moved where required. Provide an air velocity of at least 100 ft/min (0.5 m/s) across the welding arc. Place the hood as close as practical to the work. The optimal location for the hood is about 1 duct diameter from the arc. Welding - Ventilation CCOHS

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# Welding - Overview of Types and Hazards (cont.) ## Is there more than one type of welding process? There are over 70 different welding processes. The type of welding process used is related to the specific application. The most common processes are: - Shielded Metal Arc Welding (SMAW), also known as Manual Metal Arc Welding, MMAW. - Gas Tungsten Arc Welding (GTAW) or Tungsten Inert Gas (TIG) Welding. - Flux Cored Arc Welding (FCAW). - Gas Metal Arc Welding (GMAW), also known as Metal Inert Gas (MIG) Welding or hard wire welding. - Plasma Arc Welding (PAW), Plasma Arc Cutting (PAC) and Gouging - Submerged Arc Welding (SAW) - Resistance Spot Welding (RSW) or spot welding. - Air Carbon Arc Cutting (CAC-A) and Air Carbon Arc Gouging (CAG) - Oxyfuel Gas Welding (OFG), Cutting and Heating (oxygen-acetylene [oxyacetylene] (OAW) or oxygen-propane [oxy-propane] mixtures are the most common fuel mixtures used). ## What, in general, are the hazards associated with welding? Health hazards associated with welding, cutting, and brazing operations will depend on the composition and exposure level to welding fumes and gases, and to ultraviolet (UV) radiation. Health risks include respiratory irritation, metal fume fever, lung cancer, skin cancer, damage to the nervous system, asphyxiation, and other health risks. Safety hazards associated with these processes include burns, eye damage, electrical shock, cuts, injury to toes and fingers. Fires and explosions may also occur. Many of these hazards can be controlled with elimination and substitution controls (e.g., eliminate need for welding or using a using lower fume-generating welding process), engineering controls (e.g., local exhaust ventilation), work practices (e.g., remove coatings before welding, and worker training), and personal protective equipment (PPE)(e.g., respiratory protection). Risk assessments and occupational hygiene air sampling can be performed to determine health and safety risks and worker exp…

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# Welding - Ergonomics (cont.) ## What are some tips for a good working posture while welding? (cont.) - Position the welding item as flat as possible, on a horizontal surface, between waist and elbow height. Position stool or scaffolding at a comfortable height to allow working in a seated position. - Avoid working in one position for long periods of time. - Work with material slightly below elbow level when working in a sitting position. - Work with material between waist and elbow heights for comfort and precision when working in a standing position. - Use a footrest if standing for long periods. - Always store materials and tools within normal reach. - Use positioning aids to accommodate work posture. Turntable Scissor Lift What is an example of a standing workbench design? Standing Workbench Design Max Height 120 e 100 80 d C Physical dimension in cm. 60 C 40 20 0 [redacted identifier] [redacted identifier] Welder height in cm. What is an example of a seated workbench design? Welding - Ergonomics CCOHS

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CCOHS CCHST Canadian Centre for Occupational Health and Safety Centre canadien d'hygiène et de sécurité au travail Welding # Welding - Ventilation On this page Where can I find some general guidelines for welding ventilation? What types of ventilation can be used to remove air contaminants from a welder's breathing zone? What are some examples of Local Exhaust Ventilation? ## Where can I find some general guidelines for welding ventilation? Ventilation is used for three general purposes: - Remove air contaminants from a worker's breathing zone and work area, - Prevent the accumulation of flammable or combustible gases or vapours; and, - Prevent oxygen rich or oxygen deficient atmospheres. For processes such as welding, brazing, soldering, and torch cutting, the primary purpose of ventilation is to remove air contaminants from the worker's breathing zone. Different ventilation strategies may be needed in each case to remove air contaminants from the welder's breathing zone. General guidelines have been published in the CSA standard W117.2:19 (R2023) Safety in welding, cutting, and allied processes, and the ANSI (American National Standards Institute) standard Z49.1-2021 Safety in Welding, Cutting and Allied Processes. Whenever ventilation is used as a means of worker protection, the ventilation system should be used and maintained in accordance with acceptable procedures. Where ventilation alone cannot adequately protect the welder, personal protective equipment (respirators) may also be used. Select the appropriate respirator according to the hazards present, any applicable legislation, and/or to the CSA standard Z94.4:18 (R2023) Selection, Use and Care of Respirators. Welding - Ventilation CCOHS

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# What precautions should I take to prevent an electrical shock? (cont.) - Turn off the welding transformer during breaks or when not in use. Detach the remaining welding electrode on the electrode holder before leaving the welding area. - Do not hold or move the welding electrode holder and the welding return cable simultaneously when moving from one working position to another if the power source to the welding equipment has not been cut. ## What should I do in case of electric shock? - Call for medical help immediately. - DO NOT touch the victim with your "bare hands" until he or she is away from the live electrical source. - Turn off the power at the fuse box or circuit breaker panel if an appliance or electrical equipment is the electrical source or, if you can do it safely, turn off the appliance or electrical equipment and unplug it. Just turning off the equipment is not sufficient. - If the electricity cannot be turned off and the victim is still in contact with the electrical source, decide if you must move the victim or push the wire away from the victim (call for emergency help if the wire is a high-voltage power line). - If you must move a victim away from a live contact, you should insulate yourself. Wear dry gloves or cover your hands with a cloth and stand on dry insulating material like cardboard, wood, or clothes. Ensure you have good footing and will not slip or fall when trying to move the victim. - Use a dry piece of wood, broom or other dry, insulating object or material to move the wire or power source away from the victim or push the victim off the live electrical source. - Do not move the victim if there is a possibility of neck or spinal injuries (from a fall, for example) unless it is absolutely necessary. - Give artificial respiration if the victim is not breathing. - Give cardiopulmonary resuscitation (CPR) if the victim's heart has stopped (only if you are trained in CPR). - Cover burns with a sterile dressing. There may b…

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# Before performing hot work, what are some general good practices? Make sure you are following your hot work procedure. Also, consider the following items: - Make sure that all equipment is in good operating order before work starts. - Make sure that all appropriate personal protective devices are available at the site and each worker has been trained on how to use, clean, and store them properly. - Inspect the work area thoroughly before starting. Look for combustible materials in structures (partitions, walls, ceilings). - Move all flammable and combustible materials away from the work area. - If combustibles cannot be moved, cover them with fire-resistant blankets or shields. Protect gas lines and equipment from falling sparks, hot materials, and objects. - Make sure that all available fire suppression systems are in good repair and operable (e.g., sprinklers, hoses, extinguishers, etc.) - Make sure that appropriate fire extinguishers (e.g., ABC fire extinguishers) are available and easily accessible. - Sweep clean any combustible materials on floors around the work zone. Combustible floors must be kept wet with water or covered with fire-resistant blankets or damp sand. Use water ONLY if electrical circuits have been de-energized to prevent electrical shock. - Remove any spilled grease, oil, or other combustible liquid. - Vacuum away combustible debris from inside ventilation or other service duct openings to prevent ignition. Seal any cracks in ducts. Prevent sparks from entering into the duct work. Cover duct openings with a fire resistant barrier and inspect the ducts after work has concluded. - Make sure that the first-aid boxes are available and easily accessible. - Block off cracks between floorboards, along baseboards and walls, and under door openings, with a fire resistant material. Close doors and windows. - Cover wall or ceiling surfaces with a fire resistant and heat insulating material to prevent ignition and accumulation of h…

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# How do coatings affect the composition of welding fumes? Vapours or fumes can come from coatings and residues on metal being welded. Some ingredients in coatings can have toxic effects. These ingredients include: - metal working fluids, oils, and rust inhibitors - zinc on galvanized steel (vaporizes to produce zinc oxide fume) - cadmium plating - chromates - vapours from paints and solvents - lead oxide primer paints - plastic coatings Metal Coatings - A Source of Hazardous Fumes ## How do I remove the coatings? - Remove coatings from the weld area to minimize the fume. The removal of coating will also improve weld quality. - Use stripping products to remove coatings. Make sure to remove any residues before welding. - Use wet slurry vacuum removal techniques for removing very toxic coatings. - Do not grind coatings. Grinding dust may be toxic. - Follow appropriate safety procedures and use the necessary personal protective equipment during the coating removal process, which will be based on risk assessments, manufacturer's instructions, and potential exposures. Welding - Fumes And Gases CCOHS

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CCOHS CCHST Canadian Centre for Occupational Health and Safety Centre canadien d'hygiène et de sécurité au travail Welding # Welding - Ergonomics ## On this page What are ergonomic risk factors associated with welding? What are some tips for a good working posture while welding? What is an example of a standing workbench design? What is an example of a seated workbench design? What should I know before lifting cylinders manually? What should I know when moving cylinders? What should I know about lighting and colour? ## What are ergonomic risk factors associated with welding? - Lifting heavy loads (cylinders, cables, etc.). - Awkward body postures (outreached arms, awkward position of neck and head, kneeling/squatting). - Static body positioning (long duration of tasks, manual precision). - Continuous force (grip strength). ## What are some tips for a good working posture while welding? - Learn to recognize symptoms of work-related musculoskeletal disorders (WMSDs; also called repetitive strain injuries or RSIs). Repeated uncomfortable postures and tasks can cause injury. - Avoid awkward body positions which cause fatigue and reduce concentration. - Always use your hand to lower your helmet. Do not use a "jerking" motion of your neck and head. - Position yourself in a stable, comfortable posture. Welding - Ergonomics CCOHS

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# Welding - Electrical Safety (cont.) ## Completion of Circuit through the Body (cont.) Live wire Incoming power One wire is connected to the ground Ground Completion of an electric circuit through ground # What precautions should I take to prevent an electrical shock? - Make sure all cables are in good condition with no bare insulation or frayed wires to minimize the extent of live parts. - When changing the welding electrode, there is a danger of shock equal to the no-load voltage output of the welding machine. The shock can be lethal under certain conditions (such as the welding current path, amount of electric current passing though the body, and working conditions (e.g., hot, moist)). - Be careful to not touch the body, especially the face or neck, when repositioning the electrode. - Protect cables from vehicular traffic or other hazards so the cables are not damaged, cut, or pinched. - Make sure that the rod holder is insulated. - Do not replace the welding electrode with a bare hand, or with a wet welding glove. - Always keep the hands and the body dry during a welding operation. - Avoid standing in water, on wet surfaces, or working with wet hands or wearing sweaty garments. - Do not dip energized (hot) electrode holders in water. Avoid direct contact with the live parts of welding equipment and the workpiece. - Ground the work or metal to be welded to a good electrical ground. Always insulate yourself from the work and ground. - Wear proper protective equipment, such as rubber boots and rubber pads, if performing arc welding in wet or high humidity conditions. Wear rubber gloves under the welding gloves. - If the welding operation must be done on steel or other conductive material, use an insulating mat under the operator. - Place the welding transformer in a close vicinity. In case of an incident, the transformer can be switched off quickly to cut off the power source. Welding - Electrical Safety CCOHS