All forms of welding produce large clouds of toxic smoke that can quickly cause debilitating and incurable health conditions. Metal-arc welding is considered especially hazardous but there are effective measures that can be put into practice to safeguard the welder and anyone in the vicinity.
What's In The Smoke?
In reality, the vapour that is emitted during welding is a deadly combination of metal dust and gas. The dust particles measure an average of 0.0001 mm, a size so small that they only appear to become visible as smoke when gathered together in vast quantities. Undetectable and as light as air, the dust can easily be inhaled and settle in the respiratory system where it has the potential to cause cancer and other long term diseases. The composition of welding smoke regularly includes an unpleasant range of toxic substances. Arsenic, lead, asbestos and carbon monoxide are just a few of the more familiar substances. Others include cadmium oxide and manganese oxide which are both particularly poisonous while high doses of nitrogen oxide can prove to be fatal. Ozone, a pale blue gas with a distinctive aroma, forms as a result of the extremely high temperatures involved in gas-arc welding and can have a deadly effect. Welding smoke contains various combinations of dust particles depending on the form of welding and the type of metal being worked.
Stainless steel releases nickel and chromium which are both highly carcinogenic. Welders exposed to a variety of dust compounds including lead oxide, zinc and cobalt during work on galvanised metal frequently suffer from flu-like symptoms such as coughs and muscle cramps. Short term welding ailments include fatigue, irritated eyes, nausea, shortness of breath and bronchitis. Long term health problems can range from emphysema to lung cancer.
Aluminium And Ozone Gas
The dangers of working with aluminium are frequently underestimated. During welding, this lightweight metal releases fumes that primarily contain aluminium oxide. These spherical-shaped dust particles can measure as little as ten nanometres and cause a range of conditions such as bronchitis and the metal specific aluminosis, commonly known as aluminium lung, an incurable disease of the lung. Although MIG (metal inert gas) welding is one of the most popular procedures for welding aluminium, the high temperatures involved encourage the formation of a much higher concentration of the gas ozone. It is produced by a series of chemical reactions between the aluminium smelt, oxygen and ultra-violet radiation. The UV rays are intensified when reflected in the shiny surface of the aluminium and are powerful enough to continue creating ozone at a considerable distance from the welding.
Welding is a hazardous occupation but there are many safeguards that can help prevent contamination from harmful dust or smoke. Disposable dust masks and high quality industrial helmets with an integral air supply can help prevent the inhalation of dust. Extractor fans are essential for helping to keep the air clear but are usually situated at some distance from the welding. Open doors and windows provide ventilation but can help to distribute the dust, endangering other workers who are nearby. The most effective safety measure is the removal of the hazardous dust from as near to the welding as possible.
A localised exhaust system is the most effective solution as it removes the dust from the source. Lightweight and mobile, such units can easily be manoeuvred into position with the minimum of effort during welding. They have powerful levels of suction to vacuum the dust before it can disperse. Exhaust hoods that can fully rotate through 360 degrees offer a flexibility that is convenient to use while using welding equipment. In addition, the exhaust arms often have a reach of up to four metres allowing effective dust removal when welding large sections. Electro-static filters and cartridges provide superior filtration of dust.
Welding is a skill that unfortunately produces a deadly cocktail of poisonous dust and smoke with potentially life-threatening side effects. A thorough understanding of the individual metals and their compositions is the first line of defence. Investing in the highest quality equipment and mobile fume extractors is the most effective way of safeguarding health.