The potential hazards of welding include harmful smoke (a mixture of fine particles – fumes – of metal and toxic gases), intense heat and sparks, loud noises, bright light, ultraviolet and infrared radiation. Exposure to welding fumes has been a common problem for welders, especially for those involved in railroad track and shipyard welding, automobile industry, construction, and heavy equipment manufacturing. Welding fumes are internationally classified as carcinogenic to humans (IARC classification group 2B).
The composition of welding fumes depends on the type of metals and the kind of welding rods being used. If they are made of iron or steel, the main component of the fume will be iron oxide. Welding on plated, galvanized, and painted metals generates fumes with cadmium, zinc oxide, or lead. Depending on the composition of their coating, welding rods can also generate fluoride and silica. Stainless steel fumes will contain Chromium Oxide and Nickel Oxide that can cause asthma. For this reason, stainless steel welding fume is considered to be more harmful than mild steel fume.
Other toxic gases that are created during welding include Carbon Monoxide, Nitrogen Dioxides, Cadmium, and Ozone. If welding operations are being done in the presence of Chlorinated Hydrocarbons, hazardous concentrations of highly toxic Phosgene and Hydrogen Chloride may be produced.
If you cut a metal coated with paint that contains lead, welding fumes will contain Lead Oxide, which may cause lead poisoning that is harmful to your nervous system, kidneys, and reproductive system.
When galvanized steel is arc-welded, the heat of the welding arc vaporizes the zinc coating, because the boiling point of zinc is below the melting point of steel. Adverse health effects of exposure to welding fumes and gases include chronic and acute poisoning, metal fume fever, irritation of the respiratory tract, emphysema, pneumoconiosis, and other diseases.
In addition to health hazards of metal fumes and toxic gases, welding operations involve hazards of burns from flame, arc, molten metal, heated surfaces, and metal splatter. If arc welding is done near solvents containing Chlorinated Hydrocarbons, the ultraviolet light can react with the solvents to form Phosgene, a gas that is deadly in any amounts.
Personal Protective Equipment (PPE) should always be used along with, but never instead of, engineering controls and safe work practices. Proper eye shields, helmets, and a powered air respirator (PAPR) system can provide protection for your lungs, head, and eyes. With proper PPE the amount of gas and hazards welders are exposed to can be significantly reduced. These items include N95 respirators, flame-resistant gloves, safety glasses or goggles, welding helmets with appropriate filter lenses and plates, leather aprons, and long-sleeved welding jackets. Even if you wear a welding helmet with a filter plate to protect from arc rays and weld sparks, safety goggles can protect further against slag chips, grinding fragments and other hazards that can ricochet under the helmet. Welding helmet filter lenses and plates must meet the test for transmission of radiant energy prescribed in ANSI/ISEA Z87.1-2015, American National Standard for Occupational and Educational Personal Eye and Face Protection Devices. According to OSHA 29 CFR 1910.252 (b)(2)(ii)(B), “Helmets and hand shields shall be arranged to protect the face, neck, and ears from direct radiant heat from the arc.”
Flame-resistant pants or overalls and steel-toed shoes are also required. Many work sites need to have ventilation in addition to ANSI standard PPE for welders and workers in the area to stay safe. Ventilation equipment that meets UL specifications, such as a RamFan Blower with ducting that eliminates the presence of harmful fumes in the welding area. This will help prevent welders and other workers from breathing high levels of airborne contaminants and provide adequate breathing air. Adequate ventilation depends on a few factors:
Since welders work with highly toxic materials, lockers should be provided so work clothes can be stored separately from personal clothing.
40-50 welders are hospitalized every year with pneumonia caused by welding fumes, and 2 of these welders die. It is important to encourage welders to protect themselves and to report any respiratory health concerns to their managers and seek medical help in case of exposure.
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