Welding is a procedure in which two metals are heated, melted and mixed to produce a joint between them. Welding is a technical field of its own, encompassing more than 70 different welding procedures. Some common types are shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), and submerged arc welding (SAW).
Welding procedures present certain health risks to operators and nearby workers, which include exposure to metallic vapors and ultraviolet radiation. Welding, cutting and brazing operations also present a risk of accidents such as burns, eye injuries, electric shocks and cuts. Most of these hazards can be avoided with engineering controls, training, and personal protective equipment (PPE). Preventing accidents during welding is an important element of construction site safety.
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Most common welding hazards
As previously mentioned, welding creates risks for both the welders and those working nearby. It is important to be aware of the risks associated with welding and take care to avoid accidents and injuries. Here is a list of the most common hazards and risks that welding poses:
Electric shock
During arc welding procedures, energized electrical circuits are used to melt metals. This creates a risk of electric shock, which happens when a welder touches two metal objects that have a voltage difference between them. Electrocution is a serious hazard during welding and can result in serious injury or death. Even though the electric shock is not lethal, it can cause welders to lose their balance and fall from a high surface ( Source: Welderhub.com).
Electric shock incidents are classified into two categories: primary voltage shock and secondary voltage shock.
- Primary voltage shock is extremely dangerous as it ranges from 230 to 260 volts. It can occur through direct contact with the interior of welding equipment and other grounded metals.
- The most common type is secondary voltage shock, which occurs when touching part of the electrode circuit, ranging from 20 to 100 volts.
A higher voltage can produce a higher current and there is a greater risk of death from electrocution. A 50-volt shock can be enough to injure or kill an operator, depending on conditions.
The key to avoiding electrical shock is adequate insulation and all equipment must be dry and in good condition. The following recommendations can reduce the risk of electrocution during welding:
- Avoid touching the metal parts of the electrode holder, especially if your skin or clothes are damp.
- Welders must wear gloves that are dry and in good condition.
- Provide rubber mats or other types of insulation for welders.
- Perform lockout and tagout procedures when making repairs; Only qualified technicians should repair welding equipment.
- Perform proper inspection of welding equipment and electrode holder before working.
- Take extra safety measures when working in damp locations, metal structures and tight spaces where you may need to kneel or work in uncomfortable positions.
Fire risks
Welding generates sparks that reach up to 35 feet and can cause a fire hazard. When this happens, workers with grease on their clothes are at the greatest risk of getting burned. Flammable chemicals should always be kept away from welding spaces to avoid any fire that could damage the entire installation. The following measures can help prevent fires during welding:
- Keep a fire extinguisher handy.
- Organize the workspace.
- Store combustible substances such as gasoline, wood, cardboard, and flammable chemicals away from the work space.
- Use fire-resistant shields if flammable materials cannot be moved.
- Dusty locations can create additional risks during welding. The high concentration of fine particles can oxidize without warning, which may result in a sudden fire or explosion.
Fumes and Gases
Welding exposes personnel to invisible gaseous vapors such as ozone, nitrogen, chromium oxides, nickel oxides and carbon monoxide. The level of damage depends on the gas, concentration and duration of exposure. Some diseases caused by welding fumes and gases are pneumonia, asthma, cancer and metal fume fever. Effects may also include irritation to the throat, lungs and eyes. The following recommendations can minimize exposure to fumes and gases:
- Keeping your head out of the smoke cloud.
- Use local ventilation and exhaust to remove harmful gases.
- Use approved breathing devices when ventilation is insufficient.
- Monitor contaminant levels to determine air quality.
- Read the material safety data sheet (MSDS) of the electrodes to know which vapors will be released.
Physical risks
There are many physical hazards present during welding activities, such as burns, eye injuries, cuts and crushed fingers. Physical risks can be drastically reduced with adequate Personal Protective Equipment (PPE). Appropriate PPE for welders includes:
- Welding helmets with side protection: Helmets offer protection against UV radiation, particles, debris and chemical burns. Adjusting the lens filters is necessary to protect your eyes, but also to see clearly during work.
- Respirators: Provide protection against gases and vapors.
- Fire-resistant clothing: Reduces the risk of burns caused by heat, fire and radiation.
- Hearing protection: Provides protection against noise and vibration in the workplace.
- Boots and gloves: Insulated flame-resistant gloves and rubber-soled boots protect welders from hazards such as electric shock and falling objects.
Conclusion
Welding safety measures are designed to protect workers from the hazards present during welding procedures. To minimize health problems and safety injuries on the job site, training sessions and regular inspection of welding equipment are important. Workers must be aware of the dangers present during welding activities and the corresponding precautions.
