For over four decades, Henlex has committed to protecting welders and their colleagues from the dangers of welding fume. Fume particles, varying in size from 0.005 to 20 µm, can potentially deposit throughout the respiratory system. It’s widely recognized amongst welders that welding fume is toxic, but its carcinogenic nature might come as a surprise to some.

According to a report from the International Agency for Research on Cancer (IARC), welding smoke is considered a group 1 carcinogen to humans. Further, the American Conference of Governmental Industrial Hygienists (ACGIH) has classified several substances present in welding fume as carcinogenic.

This article will discuss the findings from various research studies and highlight a list of typical carcinogenic substances found in welding smoke. Additionally, we’ll provide useful advice to help welders protect themselves against cancer risks and other health concerns.

Welding fume is carcinogenic

As early as 1989, the International Agency for Research on Cancer, a branch of the World Health Organization, categorized welding fume as potentially carcinogenic. Though they suspected it, there wasn’t enough scientific data and evidence to conclusively establish this fact..

However, in 2017, the IARC definitively announced that welding smoke is carcinogenic to humans, regardless of the welding process or type of metal used. Additionally, this proclamation has been acknowledged and published by the Centers for Disease Control and Prevention, a part of the National Institute for Occupational Safety and Health (NIOSH).

Therefore, welding fume is now officially recognized as a known carcinogen that can induce lung cancer and is designated as a group 1 carcinogen, the agency’s categorization for agents that carry conclusive evidence of causing cancer in humans.

Potential Carcinogens Found in Welding Fume

The American Conference of Governmental Industrial Hygienists is a reputable organization in North America. Here’s how they classify metals and gases frequently found in welding fume.

Chromium (VI)A1
Titanium dioxideA3
Vanadium pentoxideA3
Chromium (III)A4
Iron OxideA4
Nickel (soluble compound)A4
Nitrogen dioxideA4
Nickel (metal)A5
A1 = Confirmed human carcinogen
A2 = Suspected human carcinogen
A3 = Confirmed animal carcinogen with unknown relevance to human
A4 = Not classifiable as a human carcinogen
A5 = Not suspected as a human carcinogen

Arsenic, commonly used in manufacturing alloys, typically lead or copper, can occasionally be present in welding fume. It’s identified as a confirmed human carcinogen.

Beryllium, employed as a hardening agent for copper, nickel, magnesium, and aluminum alloys, as well as electrical contacts due to its high heat capacity, can be found in welding fume. It’s a recognized human carcinogen and one of the culprits behind metal fume fever.

Hexavalent chromium can be found in fume from welding most stainless steels and high-alloy materials. Chromium is also included in the composition of welding rods or used as a plating material. High temperatures convert it to a hexavalent state, which is known to be carcinogenic for humans.

Cadmium oxides are often present in welding fume, as certain stainless steels and zinc alloys contain cadmium. It’s also used in coatings and plating. Cadmium is also present as an impurity in non-ferrous metals (zinc, lead, and copper), iron, and steel. It’s classified as a suspected human carcinogen.

Cobalt, Lead, Molybdenum, Titanium dioxide, and Vanadium pentoxide are confirmed animal carcinogens, with their impact on humans still to be confirmed through additional studies.



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Risks and Types of Cancer Linked to Welding Fume

Scientific research has demonstrated that lung cancer is more prevalent among welders than non-welders. However, evidence also suggests that welding can increase the risk of other forms of cancer, such as mesothelioma, throat cancer, bladder cancer, and kidney cancer.

An article published in 2017 in Saf Health Work demonstrated that welders are likely at a higher risk of developing lung cancer, mesothelioma, bladder cancer, and kidney cancer. Although more research is needed to validate this assertion definitively, especially to differentiate the effects of welding from smoking and asbestos exposure, the study found a 16% increased risk of lung cancer among welders and a 78% greater risk of mesothelioma than non-welders. Welding was also found to contribute to the 40% increased risk of bladder cancer and the 30% increased risk of kidney cancer.

As mentioned earlier, the International Agency for Research on Cancer has also concluded that inhaling welding smoke increases the risk of lung cancer.

Furthermore, the Cancer Council suggests that exposure to welding fumes and UV radiation enhances the risk of developing melanoma of the eye, lung, and other cancers. They claim that scientific evidence implies exposure to all welding smoke, including mild steel welding smoke, can cause lung cancer. There is also limited evidence connecting it to kidney cancer.

Over the years, numerous other studies have indicated that welding elevates cancer risk, particularly lung cancer. A quick search on PubMed will give you many results proving this point.

It’s vital to recognize that the risk of developing cancer from welding depends on several factors, including:

  • The welding process and power settings
  • The material being welded (including the plating, solvents, and coatings such as paint or lubricants)
  • The consumables (electrode, wire, etc.)
  • The shielding gas or flux
  • The working conditions and environment (outside, inside, confined space)
  • The overall air quality in the working area
  • The efficiency of fume extraction and ventilation
  • The welder’s position to prevent inhalation of smoke and gases
  • The use of personal protective equipment
  • The duration of welding each day
  • The number of days welding per week
  • The number of years spent welding
  • The health condition of the worker

Other Health Effects Linked to Welding Fume

According to OSHA, the Centers for Disease Control and Prevention, the International Agency for Research on Cancer, and the CNESST (Canada), inhalation of welding fume could lead to health effects such as:

  • Irritation of the eyes, nose, and throat
  • Dizziness and nausea
  • Breathing difficulties potentially leading to suffocation or asphyxiation
  • Metal fume fever
  • Damage to the lungs
  • Stomach ulcers
  • Damage to the kidneys
  • Damage to the nervous system
  • Manganism (a neurological condition resembling Parkinson’s disease, caused by manganese smoke)
  • Chest pain
  • Asthma
  • Bleeding
  • Dermatitis or eczema
  • Kidney disease
  • Bone and joint disorders
  • Siderosis (iron oxide in lung tissue after inhalation)
  • Stannosis (tin oxide in lung tissue after inhalation)
  • Anthracosis (poisoning after inhalation of carbon dust)
  • Berylliosis (poisoning after inhalation of beryllium dust)
  • Accumulation of fluid in the lungs

Read more about the dangers and toxicity of welding fumes.

Cancer and Other Health Problem : Prevention Tips

Here are a few pointers to protect welders and others in the vicinity sustainably from cancer and other health issues caused by welding fume:

  1. Weld only when absolutely necessary. Other procedures can sometimes replace manual welding (bolts, fasteners, robotic welding).
  2. Separate welding operations from other workers (for instance, dedicate an area or building only for welding or at the very least, use welding screens).
  3. Choose welding processes that emit less smoke, such as submerged arc, TIG, and resistance welding. Conversely, MIG and flux core tend to generate more smoke. Altering power settings could also reduce smoke.
  4. Use consumables and materials that produce less toxic smoke. For example, you should remove paint or coatings. Avoid carcinogenic substances (arsenic, beryllium, hexavalent chromium, etc.) and hazardous metals (manganese, etc.).
  5. Use welding fume extractors. For more information, refer to our comprehensive article about welding fume extractors or MIG welding fume extraction if that’s the process you’re working with.
  6. Ensure welders position themselves to avoid inhaling fume and gases. For instance, they should not place their head between the weld pool and the fume extractor. Or they could use the wind to blow the smoke away when welding outdoors.
  7. Make sure your factory has adequate ventilation.
  8. If previous measures don’t sufficiently reduce exposure to safe levels, use personal protective equipment such as masks and respirators. They should be fitted individually for each worker.

Read more about our systematic step-by-step method to solve welding fume problems.

Permissible exposure limits for welding smoke, metal smoke, and gases are regulated and enforced by health and safety agencies like OSHA throughout North America. To learn more about the maximum permissible concentrations, you can read one of the following articles:

These articles will also provide recommendations from the American Conference of Governmental Industrial Hygienists (ACGIH).

Any Questions?

Feel free to contact us. We will help you protect your workers and comply with welding fumes standards anywhere in the US and Canada.