02 Nov Weld Fume Hazards and How to Protect Yourself
Welding fuses two metal pieces together melting the base metal and a filler material forming a joint that is often stronger than the base metal. The heating of the base metal and filler causes vapours to emanate from the arc concentrating into extremely fine particles that can be exceedingly bad for human health. We have summarised some of the best practices for protecting yourself and others around you from the dangers of the welding fumes.
What is in Welding Fumes?
Welding fumes occur when a metals temperature is elevated above its boiling point. When this occurs, the metals vapours concentrate into solid particulates that are a combination of the metal being welded and the electrode. The resulting fumes are an intricate combination of silicates, fluorides and metallic oxides. The composition of welding fumes can differ depending on the type of metal and flux being used:
- Welding stainless steel produces lower amount of iron and a greater amount of nickel or hexavalent chromium.
- Mild steel welding fumes consists of mainly iron and trace amounts of metal additives like copper, titanium, cobalt, molybdenum, vanadium, hex chromium, manganese and nickel.
- Nickel alloys contains very scarce amounts of iron and has much more nickel.
- Fluxes made from fluoride or silica generates fluoride fumes, metallic silicates and amorphous silica.
Protect Yourself from Welding Fumes!
- Coatings– The safest practice with coated steel is to remove the coating completely before welding so as to prevent the coating from becoming toxic vapours from the heat of the arc. This can usually be performed with an angle grinder and flap wheel.
- Welding Outdoors– Welders working outdoors should always position themselves so that they are working upwind of the arc so that the majority of the weld fumes will travel away from them.
- Welding Indoors– When proper natural ventilation is not possible local exhaust ventilation systems should be used to help clear the welders breathing from gases and fumes. To be sure that the greatest number of fumes possible are being removed when using a local exhaust ventilation system make sure to keep the extractor guns and vacuum nozzles as close to the plume source as possible. Also, flexible exhaust systems can be used to draw the fumes away from the welder but always be sure that the ventilation is also aimed away from other workers as well.
- Confined Spaces– When welding in confined spaces always use sufficient mechanical ventilation or airline respirators and make sure to avoid blockage of ventilation equipment.
- Respiratory Mask– Always be sure to wear respiratory protection if ventilation cannot reduce fume exposures to safe levels.