As pioneers in North America, we have been offering solutions for extracting welding fumes since the 1980s. In this blog post, you’ll discover the exposure limits for some of the most frequently encountered hazardous metals and gases in welding fumes in Manitoba.

Fumes are created when a metal is heated beyond its boiling point, leading to the condensation of its vapors into extremely tiny particles. These particles range in size from 0.005 to 20 µm, with most being less than 1 µm, which can deposit throughout the respiratory system.

The composition of the fume is dependent on various factors including the material being welded, the electrode, the coatings, the flux, and the shielding gas, among others. To identify the hazardous and regulated substances present in your work environment, air sampling is generally required. However, acquiring information about the composition of metals, gases, and consumables used in the welding process is a beneficial first step.

Which particulates pose potential dangers in welding fumes?

We will cover some hazardous metals and gases typically found in welding fumes in this article:

  • Aluminum
  • Antimony
  • Arsenic
  • Beryllium
  • Cadmium
  • Chromium
  • Cobalt
  • Copper
  • Iron oxide
  • Lead
  • Manganese (learn more about manganese in welding fumes)
  • Molybdenum
  • Nickel
  • Silver
  • Tin
  • Titanium dioxide
  • Vanadium
  • Zinc
  • Argon
  • Carbon Dioxide
  • Carbon Monoxide
  • Helium
  • Hydrogen Fluoride
  • Nitric Oxide
  • Nitrogen
  • Nitrogen Dioxide
  • Ozone
  • Phosgene

Manitoba Workplace Safety and Health Act – Welding Fume Regulations

In Manitoba, businesses are required to abide by the Manitoba Workplace Safety and Health Act. Regulations pertaining to exposure limits can be found in chapter 36.5. Below is some essential information.

“In the case of an airborne substance for which the ACGIH has established a threshold limit value, establish an occupational exposure limit for the substance that does not exceed the threshold limit value established by the ACGIH.”

“In the case of an airborne designated material, establish an occupational exposure limit for the material that is as close to zero as possible and does not exceed the threshold limit value established by the ACGIH.”

Designated material: “a chemical or biological substance which meets the criteria as a carcinogen, mutagen, respiratory sensitizer or reproductive toxin under the Hazardous Products Regulations.”

When there’s no threshold limit value established by ACGIH, a competent person must define one. Certain workplace conditions or workers’ health may require the employer to establish an occupational exposure limit lower than that recommended by ACGIH to ensure safety.

In essence, companies in Manitoba must define their Occupational Exposure Limits (OEL) to guarantee the safety of their workers, using the ACGIH recommendations as the maximum permissible OEL.

Abbreviations used in the tables below:

  • TWA: Time-Weighted Average for 8 hours
  • STEL: Short-Term Exposure Limit (maximum for 15 minutes, no more than four times per day, with at least 60 minutes in between)
  • C: Ceiling (must never be exceeded)
  • (i): Inhalable particles (smaller than 100 µm)
  • (r): Respirable particles (smaller than 4 µm)



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Manitoba – Occupational Exposure Limits for Welding Fume, Metals, and Gases

As per the Manitoba Workplace Safety and Health Act, the following limits are the maximum OELs a company in Manitoba may decide to establish, provided they are considered safe for workers.

Welding Fumes≤3mg/m3(r)
Chromium (0)≤0.5mg/m3(i)NoneNone
Chromium (III)≤3µg/m3(i)NoneNone
Chromium (VI)≤0.2µg/m3(i)≤0.5µg/m3(i)None
Iron Oxide≤5mg/m3(r)NoneNone
Tin, organic≤0.1mg/m3≤0.2mg/m3None
Tin oxide & inorganic≤2mg/m3(i)NoneNone
Carbon Dioxide≤5,000ppm≤30,000ppmNone
Carbon Monoxide≤25ppmNoneNone
Hydrogen Fluoride≤0.5ppmNone≤2ppm
Nitric Oxide≤25ppmNoneNone
Nitrogen Dioxide≤0.2ppmNoneNone
* A concentration limit is not included because available oxygen is the limiting factor.

You can verify the current applicability of these maximum OELs using the links below.

ACGIH – Threshold Limit Values for Welding Fume, Metals, and Gases

Threshold Limit Values (TLV) are copyrighted by ACGIH and cannot be replicated on other websites. Below, you will find links to relevant pages on their website. Utilize these to understand the maximum OELs you could establish.

ACGIH has not issued a general recommendation concerning welding fumes. Thus, they are categorized under Particulates Not Otherwise Regulated. For such cases, ACGIH recommends a TLV-TWA of 3mg/m3 for respirable particles and 10mg/m3 for inhalable particles.

* A concentration limit is not included as the availability of oxygen is the limiting factor.

Health Risks Associated with Inhalation of Welding Fumes

According to OSHA, the Centers for Disease Control and Prevention, the International Agency for Research on Cancer, and the CNESST (Quebec), inhaling welding fumes may lead to the following health issues:

  • Eye, nose, and throat irritation
  • Dizziness and nausea
  • Breathing difficulties potentially leading to suffocation or asphyxiation
  • Metal fume fever
  • Lung damage and various forms of cancer
  • Stomach ulcers
  • Kidney damage
  • Damage to the nervous system
  • Manganism
  • Chest pain
  • Asthma
  • Hemorrhaging
  • Dermatitis or eczema
  • Kidney disease
  • Disorders affecting bones and joints
  • Siderosis (inhalation of iron oxide resulting in lung tissue deposition)
  • Stannosis (inhalation of tin oxide resulting in lung tissue deposition)
  • Anthracosis (poisoning following inhalation of carbon dust)
  • Berylliosis (poisoning following inhalation of beryllium dust)
  • Accumulation of fluid in the lungs

These reasons underscore the importance of protecting welders, adhering to standards, and removing pollutants as effectively as possible. The best tool for this is a Welding fume extractor.

For more information about welding fume regulations in other Canadian provinces or territories, feel free to click on one of the links below, which will redirect you to our relevant article on the subject:

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.