Welding Fume Regulations and Exposure Limits in Manitoba

Last updated in June 2024

We have been a pioneer in North America, providing welding fume extraction solutions since the 1980s. In this blog post, you will find the exposure limits in Manitoba for some of the most common hazardous metals and gases found in welding fume.

Fumes are formed when a metal is heated above its boiling point, and its vapors condense into very fine particles. Their size ranges from 0.005 to 20 µm, but most are smaller than 1 µm and may deposit throughout the respiratory system.

The fume composition depends on the material being welded, the electrode, the coatings, the flux, and the shielding gas, among other things. Air sampling is usually necessary to know which hazardous and regulated substances are in your working environment. But getting information on the composition of metals, gases, and consumables used in the welding process is usually a good start.

What particulates are potentially dangerous in welding fume?

Here is a list of some dangerous metals and gases commonly found in welding fume that will be covered on this page:

• 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

In Manitoba, companies must follow the Manitoba Workplace Safety and Health Act. Exposure limit regulations can be found in chapter 36.5. Here is some important 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 is no ACGIH threshold limit value, a competent person must establish one. Some conditions in the workplace or workers’ health could require the employer to establish a lower occupational exposure limit than the one from ACGIH to ensure their safety.

In short, in Manitoba, companies must establish their Occupational Exposure Limits (OEL) to ensure their workers’ safety. They must also use the ACGIH recommendations as the maximum OEL authorized.

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

Based on the Manitoba Workplace Safety and Health Act, the following limits are the maximum OELs a company in Manitoba could decide to establish if they are deemed safe for workers.

OEL	TWA	STEL	C
Welding Fumes	≤3mg/m3(r) ≤10mg/m3(i)	None	None

OEL	TWA	STEL	C
Aluminum	≤1mg/m3(r)	None	None
Antimony	≤0.5mg/m3	None	None
Arsenic	≤0.01mg/m3	None	None
Beryllium	≤0.05µg/m3(i)	None	None
Cadmium	≤2µg/m3(r)	None	None
Chromium (0)	≤0.5mg/m3(i)	None	None
Chromium (III)	≤3µg/m3(i)	None	None
Chromium (VI)	≤0.2µg/m3(i)	≤0.5µg/m3(i)	None
Cobalt	≤0.02mg/m3(i)	None	None
Copper	≤0.2mg/m3	None	None
Iron Oxide	≤5mg/m3(r)	None	None
Lead	≤0.05mg/m3	None	None
Manganese	≤0.02mg/m3(r) ≤0.1mg/m3(i)	None	None
Molybdenum	≤3mg/m3(r) ≤10mg/m3(i)	None	None
Nickel	≤1.5mg/m3(i)	None	None
Silver	≤0.1mg/m3	None	None
Tin, organic	≤0.1mg/m3	≤0.2mg/m3	None
Tin oxide & inorganic	≤2mg/m3(i)	None	None
Titanium	≤0.2mg/m3(r)	None	None
Vanadium	≤0.05mg/m3(i)	None	None
Zinc	≤2mg/m3(r)	≤10mg/m3(r)	None

OEL	TWA	STEL	C
Argon*	None	None	None
Carbon Dioxide	≤5,000ppm	≤30,000ppm	None
Carbon Monoxide	≤25ppm	None	None
Helium*	None	None	None
Hydrogen Fluoride	≤0.5ppm	None	≤2ppm
Nitric Oxide	≤25ppm	None	None
Nitrogen*	None	None	None
Nitrogen Dioxide	≤0.2ppm	None	None
Ozone	≤0.05ppm	None	None
Phosgene	None	None	≤0.02ppm

You can ensure these maximum OELs are still applicable with the links below.

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

Threshold Limit Values (TLV) are copyrighted by ACGIH and cannot be reproduced on other websites. You will find the links to the relevant pages on their website below. Use them to know the maximum OELs you could establish.

ACGIH has not published a recommendation regarding welding fumes in general. Therefore, they fall under the Particulates Not Otherwise Regulated category. The ACGIH recommendation, in this case, is a TLV-TWA of 3mg/m3 for respirable particles and 10mg/m3 for inhalable particles.

• Aluminum
• Antimony
• Arsenic
• Beryllium
• Cadmium
• Chromium
• Cobalt
• Copper
• Iron Oxide
• Lead
• Manganese
• Molybdenum
• Nickel
• Silver
• Tin, organic
• Tin oxide & inorganic
• Titanium
• Vanadium
• Zinc Oxide
• Argon*
• Carbon Dioxide
• Carbon Monoxide
• Helium*
• Hydrogen Fluoride
• Nitric Oxide
• Nitrogen*
• Nitrogen Dioxide
• Ozone
• Phosgene

* A concentration limit is not included because available oxygen is the limiting factor.

Health risks associated with breathing welding fumes

According to OSHA, the Centers for Disease Control and Prevention, the International Agency for Research on Cancer, and the CNESST (Quebec), breathing welding fumes could cause the following health effects:

• Eye, nose, and throat irritation
• Dizziness and nausea
• Breathing difficulties that could lead to suffocation or asphyxiation
• Metal fume fever
• Lung damage and various types of cancer
• Stomach ulcers
• Kidney damage
• Nervous system damage
• Manganism
• Chest pain
• Asthma
• Bleedings
• 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

These are good reasons to protect welders, meet the standards, and even extract pollutants as efficiently as possible. Welding fume extractors will be the best way to do so.

To learn more about welding fume regulations in another Canadian province or territory, feel free to use one of the links below to be directed to our article on the subject:

• Alberta
• British Columbia
• Newfoundland and Labrador
• New Brunswick
• Northwest Territories
• Nova Scotia
• Nunavut
• Ontario
• Prince Edward Island
• Quebec
• Saskatchewan
• Yukon