The dangers of welding fume have been well documented in recent times, following it’s reclassification as ‘Carcinogenic to humans’ by the International Agency for Research on Cancer (IARC). The increased awareness around the health hazards associated with welding fume has seen many Australian and New Zealand welders, and their employers, change their stance on welder’s respiratory protection.
In looking to address the risks and hazards of welding fume exposure, it is best practice to use a hierarchy of controls. The idea is that the highest priority items within the hierarchy not only do the most to reduce fumes and worker exposure, they also put the least burden of responsibility on the welder.
While these controls provide effective ways to minimise respiratory exposure to hazardous particulates and gases, each has certain limitations.
1. Modify or substitute the welding process
Where possible, look to substitute welding processes for other processes which generate less fumes or eliminate the most toxic contaminants. This also extends to reviewing the use of consumable options to see if there are less-toxic alternatives.
Control limitations: substitution may not always be possible e.g. when the end-product requires stainless steel (chromium).
2. Engineering controls
Engineering controls include modifying enclosures around the welder, or the general ventilation of the workshop, or local exhaust controls. Local exhaust ventilation systems can be used to remove fume and gases from the welder’s breathing zone. To remove the maximum amount of fume and gases, any air extraction inlet should be located as close to the plume source as possible. It is also important that any exhaust points are kept away from other workers.
Control limitations: ventilation can sometimes be difficult to achieve due to conflicting needs of the welder. Examples of these needs may be mobility, heating/cooling or shielding gases.
3. Work practices
Workers should position themselves in respect of the fume source as efficiently as possible to avoid or reduce exposure. For example, when working in an open or outdoor environment, welders can position themselves to be upwind. Or when working indoors, this could mean taking advantage of any natural drafts by positioning themselves to keep fume and gases away from themselves and other workers.
Control limitations: space-restricted work pieces or welding environments may not allow for positional alternatives
4. Personal respiratory equipment
In addition to steps 1 to 3, we always recommend personal respiratory protection to achieve the best protection and comfort. Depending on the environment, appropriate respiratory protection may include the use of a disposable or reusable respirator, powered air or supplied air respirator.
Control limitations: establishing a respiratory protection program including selection and ongoing training on product care & maintenance.
By using the hierarchy of controls outlined above, welders can ensure they reduce exposure to welding fumes. Welders should understand the hazards of the materials they are working with reference to relevant Safety Data Sheets and identification of size and scale of exposures to welding fume. OH&S Regulations require employers to provide information and training for workers on exposure to hazardous materials in the workplace.