Welding Fume Regulations and Exposure Limits in Quebec

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 Quebec 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 (learn more about aluminum welding fume)
• 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

Quebec Regulation Respecting Occupational Health and Safety – Welding Fume

In Quebec, companies must follow the Regulation respecting occupational health and safety. Permissible Exposure Values (PEV) for gases, dust, fumes, vapors, or mists in the work environment can be found in Schedule I. Chapter 107 stipulates that fume extractors are required for welding.

“Local ventilation: Any localized source at a stationary workstation that emits dusts, gases, fumes, vapours or mists shall be equipped with a local exhaust ventilation system for trapping the dusts, gases, fumes, vapours or mists at their source.”

Division V introduces the permissible exposure value table: “No worker in an establishment shall be exposed to a concentration of airborne oxygen below 19.5% in volume at normal atmospheric pressure; gases, fumes, vapours, dusts or mists, beyond the limits provided for in Schedule I.”

Finally, there is an important note in Schedule I.

“EXCURSION LIMITS: These limits apply to substances which do not have a short-term exposure value. Provided the time-weighted average exposure value is not exceeded, excursions in exposure levels may exceed 3 times that value for a cumulative period not exceeding a total of 30 minutes during a workday. Notwithstanding the foregoing, none of those excursions in exposure levels may exceed 5 times the time-weighted average exposure value during any length of time whatsoever.”

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Quebec – Permissible Exposure Values for Welding Fume, Metals, and Gases

Based on the Regulation Respecting Occupational Health and Safety, the following limits are the applicable PEVs in Quebec for welding fume and some of its components.

Abbreviations used in the tables below:

• TWAEV: The time-weighted average concentration for an 8-hour workday and a 40-hour workweek
• STEV: Short-Term Exposure Value (maximum time-weighted average concentration for 15 minutes, no more than four times per day, with at least 60 minutes in between)
• C: Ceiling (concentration never to be exceeded)
• (i): Inhalable dust (smaller than 100 µm)
• (r): Respirable dust (smaller than 4 µm)
• (t): Total dust

PEV	TWAEV	STEV
Welding Fumes	5mg/m3	None

PEV	TWAEV	STEV
Aluminum	5mg/m3(r)	None
Antimony	0.5mg/m3	None
Arsenic*	0.01mg/m3	None
Beryllium*	0.15µg/m3	None
Cadmium	0.01 mg/m3	None
Chromium metal & (III)	0.5mg/m3	None
Chromium (VI)*	0.001mg/m3	None
Cobalt	0.02mg/m3(i)	None
Copper	0.2mg/m3	None
Iron Oxide	5mg/m3	None
Lead	0.05mg/m3	None
Manganese	0.2mg/m3(i) 0.05mg/m3(r)	None
Molybdenum	3mg/m3(r) 10mg/m3(i)	None
Nickel	1.5mg/m3(i)	None
Silver	0.1mg/m3	None
Tin metal & oxide	2mg/m3(i)	None
Titanium dioxide	10mg/m3(t)	None
Vanadium pentoxide	0.05mg/m3(i)	None
Zinc oxide	2mg/m3(r)	10mg/m3(r)

PEV	TWAEV	STEV	C
Argon*	None	None	None
Carbon Dioxide	5,000ppm	30,000ppm	None
Carbon Monoxide	35ppm	200ppm	None
Helium*	None	None	None
Hydrogen Fluoride**	None	None	3ppm
Nitric Oxide	25ppm	None	None
Nitrogen*	None	None	None
Nitrogen Dioxide	3ppm	None	None
Ozone**	None	None	0.1ppm
Phosgene	0.1ppm	None	None

As a reminder, according to regulations: “Provided the time-weighted average exposure value is not exceeded, excursions in exposure levels may exceed 3 times that value for a cumulative period not exceeding a total of 30 minutes during a workday. Notwithstanding the foregoing, none of those excursions in exposure levels may exceed 5 times the time-weighted average exposure value during any length of time whatsoever.”

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, 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
• Nunavut
• Ontario
• Prince Edward Island
• Saskatchewan
• Yukon