Welding Fume Regulations and Exposure Limits in Nunavut

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 applicable in Nunavut 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

Nunavut Occupational Health and Safety Regulations – Welding Fume

Employers must comply with the Occupational Health and Safety Regulations in Nunavut.

Ventilation regulations can be found in Part 6 (General Health Requirements). Here are a few relevant quotes when it comes to welding.

“An employer shall ensure the adequate ventilation of a work site; and, to the extent that is reasonably possible, render harmless, and prevent the accumulation of, any contaminants or impurities in the air by providing an adequate supply of clean and wholesome air and maintaining its circulation throughout the work site.”

“An employer shall provide a mechanical ventilation system at a work site that is sufficient and suitable to protect workers against inhalation of a contaminant and to prevent accumulation of the contaminant […] if any work, activity or process at the work site gives off a dust, fume, gas, mist, aerosol, vapour or other airborne contaminant that is hazardous to workers.”

“An employer shall, to the extent that is reasonably possible, ensure that a mechanical ventilation system […] includes local exhaust ventilation that is installed and maintained at or near the point of origin of the contaminant so as to effectively prevent the contaminant from entering the air of the work site.”

Finally, Contamination Limits can be found in Schedule O.

“If a chemical or biological substance set out in Schedule O is present at a work site, an employer shall, to the extent that is reasonably possible, provide adequate engineering controls to ensure that the contamination limit set out in Schedule O is not exceeded; and take steps to ensure that workers’ personal exposure does not exceed the contamination limits set out in Schedule O.”

Regarding general ventilation, although not explicitly stated, the general consensus is that a minimum of 4 air changes per hour is required for industrial buildings, including those with welding operations. In confined spaces, the minimum recommended is 10 air changes per hour, though 20 or more may be necessary.

Any questions? Ask them directly in the chat at the bottom right of your screen or during one of our webinars.

Nunavut – Contamination Limits for Welding Fume, Metals, and Gases

Based on Occupational Health and Safety Regulations, the following limits are the applicable Contamination Limits (CL) in Nunavut for welding fume and some of its components.

Abbreviations used in the tables below:

• TWA: The Time-Weighted Average concentration for an 8-hour workday
• STEL: Short-Term Exposure Limit (maximum time-weighted average concentration for 15 minutes)
• C: Ceiling (concentration never to be exceeded)

CL	TWA	STEL
Welding Fumes	5mg/m3	10mg/m3

CL	TWA	STEL
Aluminum	10mg/m3	20mg/m3
Antimony	0.5mg/m3	1.5mg/m3
Arsenic	0.01mg/m3	0.03mg/m3
Beryllium	2µg/m3	0.01mg/m3
Cadmium, total	0.01mg/m3	0.03mg/m3
Cadmium, respirable**	2µg/m3	6µg/m3
Chromium metal and (III)	0.5mg/m3	1.5mg/m3
Chromium (VI), soluble	0.05mg/m3	0.15mg/m3
Chromium (VI), insoluble	0.01mg/m3	0.03mg/m3
Cobalt	0.02mg/m3	0.06mg/m3
Copper	0.2mg/m3	0.6mg/m3
Iron Oxide	5mg/m3	10mg/m3
Lead	0.05mg/m3	0.15mg/m3
Manganese	0.2mg/m3	0.6mg/m3
Molybdenum, inhalable*	10mg/m3	20mg/m3
Molybdenum, respirable**	3mg/m3	6mg/m3
Nickel, inhalable*	1.5mg/m3	3mg/m3
Silver	0.1mg/m3	0.3mg/m3
Tin metal and oxide	2mg/m3	4mg/m3
Titanium dioxide	10mg/m3	20mg/m3
Vanadium pentoxide, respirable**	0.05mg/m3	0.15mg/m3
Zinc oxide, respirable**	2mg/m3	10mg/m3

CL	TWA	STEL	C
Argon*	None	None	None
Carbon Dioxide	5,000ppm	30,000ppm	None
Carbon Monoxide	25ppm	190ppm	None
Helium*	None	None	None
Hydrogen Fluoride	0.5ppm	None	2ppm
Nitric Oxide	25ppm	38ppm	None
Nitrogen*	None	None	None
Nitrogen Dioxide	3ppm	5ppm	None
Ozone	0.05ppm	0.15ppm	None
Phosgene	0.1ppm	0.3ppm	None

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

The American Conference of Governmental Industrial Hygienists (ACGIH) is an important organization researching hazardous substances and recommending exposure limits. They influence most health and safety organizations in North America, and knowing their recommended Threshold Limit Values (TLV) is very valuable.

Threshold Limit Values are copyrighted by ACGIH and cannot be reproduced on other websites. However, you will find the links to the relevant pages on their website below.

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-TWAEV 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
• Manitoba
• Newfoundland and Labrador
• New Brunswick
• Northwest Territories
• Nova Scotia
• Ontario
• Prince Edward Island
• Quebec
• Saskatchewan
• Yukon