Safety in Welding
07 September 2012
Arc welding and cutting processes, as well as other forms of welding, produce radiation. The quantity of radiation could be small, but in some cases ultraviolet or infrared radiation can go undetected. Such radiation can cause eye damage or skin burns. It is therefore necessary to use a welding helmet with the correct shade of filter plate, gloves and the correct clothing. Screen curtains can be used to protect other people in the vicinity. Safety glasses should have UV protective side shields. In addition, noise caused by welding can be hazardous, with temporary or permanent loss of hearing occurring. Ear muffs or ear plugs can be used as protection.
Electric shock from welding and cutting equipment is another danger that can result in injury or even death. When welding there are various components that are electrically energised, such as the welding circuit, the internal circuits, the reel of wire or the drive rolls. Incorrectly installed equipment or equipment which has not been properly grounded is normally the cause of electrical shocks during welding. To avoid electrical shock it is important to follow the instructions of the equipment in use. Employees should be trained on how to avoid electrical injuries. Principles such as not touching live electrical parts, having installations and maintenance done by qualified people, having the equipment grounded at all times and frequently inspecting power cords for open wires should be adhered to. When conditions are less than perfect it is important not to work alone, wear insulating gloves and rubber soled boots, while making use of mats and insulated electrode holders. Of course, water should be avoided under all circumstances.
Further possible hazards of welding include fire and explosions. The main danger comes from flying sparks. According to the American Welding Society, sparks can travel up to 10.7meters from the work area and can pass through or become lodged in cracks, clothing, pipe holes and other small openings in floors, walls or partitions. There are many combustible materials in and around a building which can catch alight from just one spark. Where flammable gases or liquids are present, such sparks can cause an explosion or even multiple explosions. In order to avoid fires and explosions it is necessary to follow the correct processes and procedures, use the correct equipment and remove as many combustible materials as possible – or at least cover such combustible material with fire resistant material. Fire resistant screens and blocking any openings can further protect the welder and the environment. It is important to ensure that the welding object has no combustible coating and no combustible internal structure.
As with all fire hazardous areas, it is essential to ensure that there is no possibility of a fire before, during and after welding; be careful of where hot slag is disposed of and keep a fire extinguisher close by.
The most common cause of electrical fire is overloading or incorrect size input conductors. The infamous Kinross mining disaster, during which 177 mine workers died, was caused by welding in an atmosphere containing reactive and toxic gases. A welder’s spark ignited plastic foam which lined the walls of a tunnel. The foam was used to stop water seepage, but contained a sealant called Rigiseal which gave off poisonous fumes when it burnt.
It is clear that safety in welding is an important factor, however, health and safety is not just incident related. There are health hazards related to welding that are not incident related. Such issues include repetitive motion injury, which is the result of repetitive reaching, bending, heavy lifting, using continuous force, working with vibrating equipment and incorrect posture. The result of repetitive motion injury and incorrect ergonomics in welding will reduce productivity, quality and worker satisfaction. It will also lead to increased absenteeism and increased staff turnover. Welding employees should look out for symptoms of repetitive motion injury, such as; less gripping strength, less range of motion, loss of muscle function, painful joints, tingling or numbness, shooting or stabbing pains, swelling or inflammation, stiffness or a burning sensation.
In order to avoid repetitive motion injury, fixed work positions or positions where the arms are raised above shoulder level should be avoided. The lighter the hand tool the better, alternatively hand tools can be suspended. Welders should be given enough opportunity to rest and the size of the workspace, the lighting, temperature, noise levels and the physical requirements of the job should be taken into account when health risks are being assessed. Welders should be aware of the dangers of the job and ensure that they are mentally ready, alert and can concentrate. Regulatory requirements can be found in The Minerals Act, 50 of 1991, The Mine Health and Safety Act 29 of 1996 and The Occupational Health and Safety Act, 85 of 1993.
Welding can be hazardous to health and safety, but for each type of hazard or injury there are safety procedures, protective gear and policies available to mitigate the risk. SAIW is soon introducing a new one week Health and Safety course, which will focus on safety precautions against electrical and gas risks. Legal requirements with regards to Health and Safety will also be addressed. The course will be suitable for anybody involved in welding. Enrolments for the course will open soon. Please check the SAIW website at www.saiw.co.za for announcements regarding when the course will commence.