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Welding Hazards and Your Workplace

A recent article published by IARC (International Agency for Research on Cancer) estimates that 11 million workers worldwide have a job title of “welder” and an additional 110 million workers probably incur welding related exposures such as fumes, gases, radiation, asbestos, and solvents. The hazards from welding extend beyond the welders. People working with and near welders are also susceptible to the same carcinogens as the welders. It is also possible that the workers near the welders could be exposed to far higher levels of toxins if proper measures are not taken to contain the fumes and light radiation emitted from welding.

welding air filtration units in use

The three tables below list the known hazards produced by welding processes. This table is published by the Canadian Centre for Occupational Health and Safety. Additional information can be found on OSHA’s website as well.

Table 1
Source and Health Effect of Welding Fumes
Fume TypeSourceHealth Effect
AluminumAluminum component of some alloys, e.g., Inconels, copper, zinc, steel, magnesium, brass and filler materials.Respiratory irritant.
BerylliumHardening agent found in copper, magnesium, aluminum alloys and electrical contacts.“Metal Fume Fever.” A carcinogen. Other chronic effects include damage to the respiratory tract.
Cadmium OxidesStainless steel containing cadmium or plated materials, zinc alloy.Irritation of respiratory system, sore and dry throat, chest pain and breathing difficulty. Chronic effects include kidney damage and emphysema. Suspected carcinogen.
ChromiumMost stainless-steel and high-alloy materials, welding rods. Also used as plating material.Increased risk of lung cancer. Some individuals may develop skin irritation. Some forms are carcinogens (hexavalent chromium).
CopperAlloys such as Monel, brass, bronze. Also some welding rods.Acute effects include irritation of the eyes, nose and throat, nausea and “Metal Fume Fever.”
FluoridesCommon electrode coating and flux material for both low- and high-alloy steels.Acute effect is irritation of the eyes, nose and throat. Long-term exposures may result in bone and joint problems. Chronic effects also include excess fluid in the lungs.
Iron OxidesThe major contaminant in all iron or steel welding processes.Siderosis – a benign form of lung disease caused by particles deposited in the lungs. Acute symptoms include irritation of the nose and lungs. Tends to clear up when exposure stops.
LeadSolder, brass and bronze alloys, primer/coating on steels.Chronic effects to nervous system, kidneys, digestive system and mental capacity. Can cause lead poisoning.
ManganeseMost welding processes, especially high-tensile steels.“Metal Fume Fever.” Chronic effects may include central nervous system problems.
MolybdenumSteel alloys, iron, stainless steel, nickel alloys.Acute effects are eye, nose and throat irritation, and shortness of breath.
NickelStainless steel, Inconel, Monel, Hastelloy and other high-alloy materials, welding rods and plated steel.Acute effect is irritation of the eyes, nose and throat. Increased cancer risk has been noted in occupations other than welding. Also associated with dermatitis and lung problems.
VanadiumSome steel alloys, iron, stainless steel, nickel alloys.Acute effect is irritation of the eyes, skin and respiratory tract. Chronic effects include bronchitis, retinitis, fluid in the lungs and pneumonia.
ZincGalvanized and painted metal.Metal Fume Fever.


Table 2
Source and Health Effect of Welding Gases
Gas TypeSourceHealth Effect
Carbon MonoxideFormed in the arc.Absorbed readily into the bloodstream, causing headaches, dizziness or muscular weakness. High concentrations may result in unconsciousness and death
Hydrogen FluorideDecomposition of rod coatings.Irritating to the eyes and respiratory tract. Overexposure can cause lung, kidney, bone and liver damage. Chronic exposure can result in chronic irritation of the nose, throat and bronchi.
Nitrogen OxidesFormed in the arc.Eye, nose and throat irritation in low concentrations. Abnormal fluid in the lung and other serious effects at higher concentrations. Chronic effects include lung problems such as emphysema.
Oxygen DeficiencyWelding in confined spaces, and air displacement by shielding gas.Dizziness, mental confusion, asphyxiation and death.
OzoneFormed in the welding arc, especially during plasma-arc, MIG and TIG processes.Acute effects include fluid in the lungs and hemorrhaging. Very low concentrations (e.g., one part per million) cause headaches and dryness of the eyes. Chronic effects include significant changes in lung function.


Table 3
Source and Health Effect of Organic Vapors as a result of Welding
Gas TypeSourceHealth Effect
Aldehydes (such as formaldehyde)Metal coating with binders and pigments. Degreasing solventsIrritant to eyes and respiratory tract.
DiisocyanatesMetal with polyurethane paint.Eye, nose and throat irritation. High possibility of sensitization, producing asthmatic or other allergic symptoms, even at very low exposures.
PhosgeneMetal with residual degreasing solvents. (Phosgene is formed by reaction of the solvent and welding radiation.)Severe irritant to eyes, nose and respiratory system. Symptoms may be delayed.
PhosphineMetal coated with rust inhibitors. (Phosphine is formed by reaction of the rust inhibitor with welding radiation.)Irritant to eyes and respiratory system, can damage kidneys and other organs.

* Source of Tables: https://www.ccohs.ca/oshanswers/safety_haz/welding/fumes.html

The initial major concerns from welding are manganese and hexavalent chromium, where overexposure to manganese has been known to cause brain damage and hexavalent chromium can lead to cancer. In an article published in March 2017, IARC recently re-classified welding fumes and UV radiation as Group 1 carcinogens. They were previously classified in Group 2B as “possibly carcinogenic to humans”. According to the agency, its new classification for welding fumes is based on “substantial new evidence” from observational and experimental studies.

It is becoming more evident that there is increased motivation to protect workers from welding fumes and UV radiation. Exposure to welding fumes and UV radiation doesn’t just harm workers, you can lose your valuable employees if you don’t provide a clean and safe work environment. In many manufacturing facilities welding smoke and plant air pollution issues seem to disappear during the mild weather months. We hear this from a variety of potential customers. Opening doors and windows to provide plant ventilation seems to be a common practice. As the colder months begin to approach, these air pollutants seem to reappear. Many companies filter their air and temperature control their facilities year around. This route is a good practice because they are not simply passing those pollutants on to their neighbors. Passive welding smoke is similar to second hand cigarette smoke. We have realized changes in laws that have made restaurants and other indoor gathering places much safer. We are also realizing similar changes that will help to make the workplace a much safer place to be.

To determine if your company has air quality issues, you will need to perform air testing and evaluate your workplace for best practices. Industrial hygienists and testing laboratories that specialize in sampling air can be consulted to assist you to ensure your employees are protected.

Air Quality Engineering Inc. offers a wide range of filtration equipment to address welding smoke and a variety of other applications. We design and manufacture both source capture and ambient (whole shop) solutions. Contact us today so we can discuss your air filtration needs.