How much Welding Fume does a welder breathe?
When resting, a human breathes around 7-8 litres of air per minute. A welder will typically breathe around 20 litres of air per minute. That fact alone tells you that welding is most certainly a physical profession. In a year, this means a welder will breathe approximately 2,300m3 of air. Knowing how many cubic metres of air a welder breathes per year allows us to calculate the quantity of welding fume an unprotected welder breathes in each year while working within the workplace exposure limits set by Safe Work Australia. We’ll then let you decide whether you think welding unprotected within the guidelines is the right move for you.
Australian workplace exposure limit for welding fume
The current Australian workplace exposure limit for general welding fume is 5 mg/m3 TWA (Time Weighted Average). This means that the maximum average airborne concentration of total welding fume when calculated over an 8-hour working day, over a five-day working week, must not exceed 5 milligrams of substance per cubic metre of air in the breathing zone (inside the welder’s welding helmet when worn).
Therefore, if a welder breathes 2,300m3 of air with 5mg of welding fume per cubic metre of air the welder may inhale up to 11.5 grams of welding fume per year. So, year on year, an unprotected welder operating within the workplace exposure limits can inhale up to 11 grams of a now known and classified carcinogen.
Welding and Cancer
“The incidence of cancer is usually dose related”3 meaning that “the greater the exposure to the carcinogen, the higher the risk of developing the cancer associated with that substance or mixture. Conversely, the smaller the exposure, the lower the probability of developing cancer”3. Welding fume was recently reclassified as a carcinogen, meaning that there is “sufficient evidence to establish a relationship between human exposure to this substance and the development of cancer” 3.
Therefore, the question remains, is welding unprotected within the Australian workplace exposure limits suitable for you? Is 11 grams of a known carcinogen too much?
Powered Air Purifying Respiratory Protection
A Powered Air Purifying Respirator or PAPR for short, like the Adflo PAPR connected to a Speedglas Welding Helmet reduces the welder’s exposure to 1/50th. If you, like many welders out there currently wear a disposable respirator or reusable respirator under your welding helmet you may be surprised to hear that a powered air respirator will give you 5 times the reduction in exposure to welding fume than what you are currently using. By making the switch you can increase your comfort and reduce your exposure to a known carcinogen.
A number of large Australian companies are now changing their stance on PPE for welders after the reclassification of welding fume by the IARC. Many companies are now strengthening their controls by enforcing the use of powered air purifying respirators (PAPR) to reduce welding fume exposure to “as low as reasonably practicable”.
If you weld, someone you care about welds or you work within the welding industry and would like to learn more about welding fume or welding helmets with powered air purifying respirators, please use our resources below:
3) Guidance on the interpretation of workplace exposure standards for airborne contaminants, Safe Work Australia, April 2013