Having pioneered the provision of welding fume extraction solutions in North America since the 1980s, we delve into the exposure limits in British Columbia for some of the most typical hazardous metals and gases present in welding fume in this blog post.
Fumes are created when a metal is heated beyond its boiling point and its vapors subsequently condense into extremely fine particles. Their size varies from 0.005 to 20 µm, but the bulk of them are under 1 µm and can deposit throughout the respiratory system.
The fume’s composition is influenced by the material being welded, the electrode, the flux, the coatings, and the shielding gas, among others. It’s typically essential to conduct air sampling to ascertain which hazardous and regulated substances are present in your work environment. However, an initial understanding of the composition of the metals, gases, and consumables used in the welding process can be beneficial.
What particulates are potentially dangerous in welding fume?
This page will cover a selection of hazardous metals and gases frequently detected in welding fumes:
- Iron oxide
- Manganese (learn more about manganese in welding fumes)
- Titanium dioxide
- Carbon Dioxide
- Carbon Monoxide
- Hydrogen Fluoride
- Nitric Oxide
- Nitrogen Dioxide
British Columbia Occupational Health and Safety Regulation – Welding Fume
Companies in British Columbia must comply with the Occupational Health and Safety Regulation. This regulation encompasses legal mandates that every workplace under the scrutiny of WorkSafeBC must fulfill. Part 5 is focuses on chemical and biological agents.
Section G5.48-5 is notable as it pertains to welding fumes. Here are some noteworthy segments.
“Except as otherwise determined by the Board, the employer must ensure that no worker is exposed to a substance that exceeds the ceiling limit, short-term exposure limit, or 8-hour TWA limit prescribed by ACGIH.”
“To determine the potential level of exposure to welding fumes, a systematic review of the base metal, electrode, and type of process is required. Information requirements for hazardous materials covered by WHMIS are found in sections 5.3-5.18 of the Regulation, and for all substances, in section 5.2. The safety data sheets (SDS) or other applicable information sources should be used to identify hazardous ingredients and expected products of reaction and decomposition. Information on electrodes, the metal(s) being welded or cut, and the specific type of welding process should also be identified.”
“Once the information on possible types of exposure has been determined, the Table of Exposure Limits for Chemical and Biological Substances should be consulted for the applicable exposure limit(s).”
Additionally, Section G5.49 states that: “If a substance referred to under section 5.48 is provided only with an 8-hour TWA limit, the employer must, in addition to the requirement of section 5.48, ensure that a worker’s exposure to the substance does not exceed three times the 8-hour TWA limit for more than a total of 30 minutes during the work period, and five times the 8-hour TWA limit at any time.”
WorkSafe BC has also created an informational page on welding fumes and gases, which offers several suggestions on reducing risks to workers. These include using a process that produces fewer fumes, implementing local exhaust ventilation, enhancing general ventilation, and more.
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British Columbia – Threshold Limit Values for Welding Fume, Metals, and Gases
As stated earlier, WorkSpaceBC uses ACGIH Threshold Limit Values (TLVs) to set the majority of Exposure Limits. However, certain exceptions exist as outlined in section R5.48-1. Here are a few relevant to welding fumes.
Abbreviations used in the table 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, no more than four times per day, with at least 60 minutes in between)
- C: Ceiling (concentration never to be exceeded)
- (r): Respirable dust (smaller than 4 µm)
- (t): Total dust
|Chromium (0) & (III)||0.5mg/m3||None||None|
|Chromium (VI), insoluble||0.01mg/m3||None||None|
|Chromium (VI), soluble||0.025mg/m3||None||None|
For all other substances mentioned on this page, ACGIH TLVs apply. Threshold Limit Values are copyrighted by ACGIH and cannot be reproduced on other websites. Nevertheless, you’ll find links to the relevant pages on their website below.
ACGIH has not issued a specific recommendation concerning welding fumes. Therefore, they are categorized under Particulates Not Otherwise Regulated. In this context, the ACGIH recommendation is a TLV-TWA of 3mg/m3 for respirable particles (smaller than 4 µm) and 10mg/m3 for inhalable particles (smaller than 100 µm).
- Zinc Oxide
- Nitric Oxide
* Simple asphyxiant: 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), inhaling welding fumes could result in various health issues, including:
- 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
- Chest pain
- 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 reasons underscore the importance of safeguarding welders, adhering to standards, and effectively removing pollutants. Welding fume extractors are the optimal tool for this purpose.
For more information on welding fume regulations in other Canadian provinces or territories, feel free to follow one of the links below to our corresponding article:
- Newfoundland and Labrador
- New Brunswick
- Northwest Territories
- Nova Scotia
- Prince Edward Island
Feel free to contact us. We will help you protect your workers and comply with welding fumes standards anywhere in the US and Canada.