Regulations and Exposure Limits on Welding Fume in Nunavut

Being a leader in North America since the 1980s, we have been providing solutions for welding fume extraction. In this article, you will discover the exposure limits established in Nunavut for some of the most frequently encountered hazardous metals and gases present in welding fumes.

Fumes are produced when a metal is heated above its boiling point, leading to vapors that condense into extremely fine particles. These particles range from 0.005 to 20 µm in size, but most are less than 1 µm, and they can deposit throughout the respiratory system.

The composition of fumes depends on several factors including the material being welded, the electrode, coatings, flux, and shielding gas, among others. Air sampling is often required to identify the hazardous and regulated substances in your workplace. However, understanding the composition of metals, gases, and consumables used in the welding process is typically a useful starting point.

Which particulates in welding fumes are potentially harmful?

Here are some of the hazardous metals and gases commonly present in welding fumes that will be discussed 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

Nunavut Occupational Health and Safety Regulations for Welding Fumes

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

Part 6 of the regulations deals with General Health Requirements, including ventilation. Here are some pertinent excerpts in relation 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.”

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

In accordance with Occupational Health and Safety Regulations, the following are the Contamination Limits (CL) in Nunavut for welding fumes and some of their 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 a significant entity that studies hazardous materials and proposes exposure limits. Their recommendations influence numerous health and safety organizations throughout North America, thus, understanding their suggested Threshold Limit Values (TLV) is greatly beneficial.

ACGIH holds copyright over Threshold Limit Values and hence these cannot be copied onto other platforms. However, we have provided the relevant links to their website below for your convenience.

As ACGIH has not issued a specific recommendation for welding fumes, these are categorized under Particulates Not Otherwise Regulated. In such instances, the ACGIH proposes a TLV-TWAEV of 3mg/m3 for particles that can be inhaled and 10mg/m3 for particles that can be ingested.

• 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 Inhalation of Welding Fumes

As stated by entities like OSHA, the Centers for Disease Control and Prevention, the International Agency for Research on Cancer, and the CNESST (Quebec), the following health hazards could potentially arise from the inhalation of welding fumes:

• Accumulation of fluid in the lungs
• Anthracosis (poisoning following inhalation of carbon dust)
• Asthma
• Berylliosis (poisoning after inhalation of beryllium dust)
• Bleedings
• Bone and joint disorders
• Chest pain
• Dermatitis or eczema
• Dizziness and nausea
• Eye, nose, and throat irritation
• Kidney damage and disease
• Lung damage and various types of cancer
• Manganism
• Metal fume fever
• Nervous system damage
• Respiratory difficulties potentially leading to suffocation or asphyxiation
• Siderosis (accumulation of iron oxide in lung tissue following inhalation)
• Stannosis (deposition of tin oxide in lung tissue after inhalation)
• Stomach ulcers

These potential health risks underline the necessity to safeguard welders, adhere to the set standards, and strive for the highest possible efficiency in pollutant extraction. Welding fume extractors are considered the optimal method for this purpose.

For further insights on the regulations surrounding welding fumes in other Canadian provinces or territories, please refer to the following links to navigate to our respective articles on the subject:

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

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.

1-866-800-8421
info@airgomig.com