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 British Columbia 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:
- 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
In British Columbia, companies must follow the Occupational Health and Safety Regulation. It contains legal requirements that must be met by all workplaces under the inspectional jurisdiction of WorkSafeBC. Part 5 is about chemical and biological agents.
Section G5.48-5 is interesting as it is about welding fumes. Here are some parts to know.
“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).”
In section G5.49, it is also said 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 also provides an informational page worth reading about welding fumes and gases. You will find a few tips on reducing the risks for workers, including using a process that generates fewer fumes, using local exhaust ventilation, improving general ventilation, etc.
If you have any questions about welding fume, do not hesitate to contact us. We will be happy to give you some insight, and we can even visit you for free in the US and Canada.
British Columbia – Threshold Limit Values for Welding Fume, Metals, and Gases
As mentioned earlier, WorkSpaceBC uses ACGIH Threshold Limit Values (TLVs) to establish most of the Exposure Limits. But some exceptions can be found in section R5.48-1. Here are a few of them that interest us when it comes to welding fume.
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 the other substances discussed on this page, ACGIH TLVs apply. 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 (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), 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
- 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 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:
- 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.