In 2017, the International Agency for Research on Cancer (IARC) released new scientific evidence showing that exposure to mild steel welding fume can cause lung cancer, and possibly kidney cancer, in humans. As a result, mild steel welding fume has been reclassified as a human carcinogen in the United Kingdom, and it is likely that other countries will follow suit. Moreover, this recent discovery indicates that all welding fume should be seen as potentially carcinogenic, and that measures will need to be taken in order to reduce the health hazards caused by welding fume exposure.
The reevaluation of mild steel welding fume
Some of the components of welding fume, such as oxides of chromium, nickel, cadmium and manganese, are known or suspected carcinogens. As stainless steel welding fume has a higher content of these alloying elements (as well as carbon) than mild steel welding fume does, the former was up until recently thought to be significantly more hazardous. What the IARC discovered is that while mild steel welding fume contains much lower concentrations of these elements, the concentrations are still potent enough to cause cancer in humans.
What makes welding fume dangerous
The fume created by welding processes is made up of solid particulates (ranging from 10 nanometers to 20 microns in size), which are formed when metallic vapours condense. Much of this fume is respirable and can penetrate deep into the lungs, where it can do significant harm and also spread into the bloodstream.
What further exacerbates the risk of exposure is that the act of welding requires the welder to locate his or her head – and, hence, breathing zone – close to the point of fume generation, as the welder simply needs to see the weld progressing. Unless there is adequate fume capture in place, the welder will be exposed to a high concentration of hazardous fumes.
The risk of welding fume exposure is not limited to welders
While the proximity to the fume source (and its significant fume concentration) puts the welder at an especially high risk of exposure, fugitive emissions may affect other personnel as well. This a key reason why effective at source capture is the recommended engineering control method, as it prevents the fume from entering and spreading throughout the general atmosphere. It is also for this reason that general ventilation without at source capture, with the welder alone wearing respiratory protection (once a common method of fume control), is no longer recommended.
Welding fume poses other health risks besides lung and kidney cancer
Welding fume exposure can lead to many illnesses and health complications. Inhalation of iron oxide particles can cause the benign lung disease Siderosis. A more serious affliction is that of metal fume fever, which is caused by beryllium, zinc and manganese, and may result in damages to the central nervous system. Fluorides often used in electrode coatings can cause irritation of the eyes, nose and throat, and long-term exposure can even result in bone and joint problems, and a chronic excess of fluid in the lungs. There have also been studies showing that the ultraviolet radiation from the welding process can contribute to skin cancer, just like the ultraviolet radiation from the sun. For welders, the neck and the area surrounding it (which is often unprotected) is especially prone to exposure.
Just having a welding fume extraction system in place will not suffice
At Nederman, we far too often see perfectly good fume extraction equipment pushed aside in workshops, as the welders do not appreciate the need to use it. Other times, we see equipment being used incorrectly, with capture hoods located too far away from the source of the fume to be effective, or even placed in such a position that the fume is drawn up through the operators breathing zone.
It is essential that the operator is trained to appreciate why the fume extraction equipment is there and how it should be used, for his or her personal benefit as well as that of the colleagues in the workplace. Being trained how to use fume extraction equipment properly should be as important as being trained to weld, as it could have life-saving consequences.
What is Nederman doing to increase welder safety?
Nederman has developed an industry-leading portfolio of at source fume capture products which minimise the welder’s exposure to hazardous welding fume. We are able to offer efficient solutions for any welding application, whether it is high air volume positionable extraction arms or low volume high vacuum extraction on the welding torch. The latter is becoming steadily more popular due to the development of lighter, more user friendly welding torches with built in extraction shrouds. These solutions come in the form of both single user machines (mobile or portable) such as FilterCart and Fume Eliminator, and multi user fixed extraction systems.
If you have any questions about this subject, or how we can help you find a suitable fume extraction system for your factory or workshop, do not hesitate to contact me. You can also read more about mild steel welding fume has been reclassified as a human carcinogen in the United Kingdom, the risks of dust and fume, as well as robotic welding fume extraction and many other related topics here in the Nederman Knowledge Center.