Welding fumes are infamously dangerous, with their toxicity being a major concern for health and safety organizations that continually revise regulations to bolster worker protection. Consequently, general ventilation alone falls short of meeting these ever-evolving standards, necessitating the use of welding fume extractors. If you’re thinking about purchasing one, this article will provide comprehensive insights to guide your decision.
The efficacy of welding fume extractors isn’t up for debate – these machines are often instrumental in achieving compliance with health and safety standards. To optimize outcomes, it’s crucial to select an extractor compatible with your specific welding process, guarantee sufficient airflow for effective extraction, and ensure welders use the extractor properly.
In the forthcoming sections, this article will delve into details about permissible exposure limits, introduce you to various welding fume extractor types and their applicable situations, and offer guidelines on maintaining adequate airflow for optimal performance.
Do you need a fume extractor for welding?
In the vast majority of circumstances, general ventilation systems are insufficient in protecting workers from inhaling harmful welding fumes. Therefore, welding fume extractors have become essential tools to safeguard welders’ health and meet health and safety regulations. This holds true regardless of the welding process employed, be it MIG/GMAW, TIG/GTAW, Stick/SMAW, FCAW, and so forth.
In the US, the Occupational Safety and Health Administration (OSHA) has established Permissible Exposure Limits (PEL), which represent the maximum average concentration of a substance in the air within the welder’s breathing zone over an 8-hour period:
- For Welding Fumes from iron, mild steel, or aluminum: 5 mg/m3
- For Hexavalent Chromium (common in stainless steel welding fumes): 5 μg/m3
Furthermore, some elements found in welding fumes must not exceed their specific PELs. This stipulation is particularly relevant when welding materials such as stainless steel, cadmium, lead-coated steel, copper, nickel, or chrome. The ACGIH also proposes a threshold limit value of 0.02 mg/m3 for manganese oxide in the welder’s breathing zone.
In Canada, each province or territory sets its exposure limit, typically ranging from 3 to 10 mg/m3. Some jurisdictions differentiate between inhalable and respirable particles. Several toxic substances present in welding fumes, like chromium or nickel, also have established exposure limits. To learn more, consult your local Health and Safety Regulations or contact our team.
Below, we list the exposure limits for welding fumes across the various Provinces and Territories in Canada.
- TWA: Time-Weighted Average over 8 hours
- STEL: Short-Term Exposure Limit (maximum for 15 minutes, no more than four times per day with at least 60 minutes in between)
- C: Ceiling (must never be exceeded)
- (i): Inhalable particles (smaller than 100 µm)
- (r): Respirable particles (smaller than 4 µm)
- ALARA: As low as reasonably achievable
** For 30 minutes during a workday.
Breathing welding fumes could cause the following health effects:
- eye, nose, and throat irritation;
- metal fume fever;
- dizziness and nausea;
- stomach ulcers;
- kidney damage;
- lung damage and various types of cancer;
- nervous system damage;
- Parkinson’s–like symptoms from extended exposure to manganese fume;
For additional information, you can consult the OSHA Fact Sheet about Welding Fumes.
Remember, fume extractors can also serve as a vital safety measure for non-welding personnel in the vicinity of welding operations, which is another key consideration.
Different types of Welding Fumes Extractors
Fume extraction MIG gun
Fume extraction MIG guns are the optimal solution for controlling MIG welding fumes. These fumes are drawn away directly from the gas nozzle through the handle and a flexible hose that wraps around the power cable. The necessary vacuum can be produced either by a standalone portable unit or a centralized system. Apart from this functionality, these fume extractors operate similarly to conventional MIG guns, allowing welders to perform their tasks without the need to consider positioning a separate fume extraction device. This on-tool extraction is efficient for all weld lengths and positions.
A conducted case study demonstrates the capacity of this technology to meet OSHA’s Permissible Exposure Limit for welding fumes and the ACGIH’s recommendation for manganese oxide. A manufacturer of steel parts put the AIRGOMIG gun to the test over several days. An independent firm was hired to perform air sampling based on methods and protocols recognized in both Canada and the United States, with the sampling filter situated inside the welder’s helmet. The MIG gun underwent testing during 8-hour shifts for three days using solid, metal-core, and fluxed-core wires. The average concentration of welding fumes ranged between 0.45 and 0.69 mg/m3 (significantly below OSHA’s PEL), and the level of manganese oxide remained below 0.015 mg/m3 (when ACGIH recommends 0.020 mg/m3).
Discover more about the advantages and disadvantages of fume extraction MIG gun here.
Fume extraction arm
Fume extraction arms present a reliable solution for all welding processes. They are typically mounted on walls, ceilings, or directly on a table and can be positioned a foot or two from the welding pool while maintaining high efficiency. Certain arms can cover up to 600 square feet depending on their length. Other portable units come equipped with a blower and filter. Correct positioning is critical for optimal performance.
Fume extraction nozzle
f a MIG gun fume extractor is unsuitable and the flexibility of an extraction arm falls short of your needs, fume extraction nozzles may be the answer. These nozzles typically feature magnets or suction cups and must be positioned a few inches from the welding pool for effective operation. This solution is cost-effective but does demand frequent repositioning by the welder.
Fume extraction hood
While fume extraction hoods can’t adequately protect a welder (since the welder’s head would be positioned between the welding area and the hood), they are ideal for robotic welding, offering superior fume extraction efficiency in such scenarios.
Contrary to popular belief, downdraft tables are not suitable for welding fume extraction. Attempting to extract welding fumes that naturally rise at high speeds from below is impractical. As such, downdraft tables either prove ineffective for welding fumes, or the airflow required to make them functional is prohibitively expensive. Downdraft tables are better suited for plasma cutting or grinding workstations, but not for welding.
The Best Way to Remove Welding Fumes for Each Process
|MIG / GMAW||Best||Yes||Yes||No||No|
|TIG / GTAW||No||Best||Yes||No||No|
|Fluxed-Cored / FCAW||Best||Yes||Yes||No||No|
|Stick / SMAW||No||Best||Yes||No||No|
** When MIG welding aluminum, a fume extraction MIG gun such as AIRGOMIG will be the most efficient (with an aluminum liner). Otherwise, a flexible arm is to favor.
*** On-tool extraction is possible for grinders and would be the most efficient solution in most cases.
**** For a CNC plasma table, it is possible to extract at the source with a Teflon extraction nozzle.
Necessary Airflows for Effective Outcomes
The required airflow depends on several factors, including welding parameters, welding position, proximity of the extractor, materials being welded, and coatings in use. However, here are some general guidelines for the minimum airflow required at the extractor:
- Fume extraction MIG gun: 100 cfm
- 3” fume extraction arm: 200 cfm
- 4” fume extraction arm: 300 cfm
- 6” fume extraction arm: 500 cfm
- 8” fume extraction arm: 700 cfm (An 8” fume extraction arm is not recommended as it takes a lot of space and is expensive to buy and operate). See our article about the best fumes extractors for more information.
- 2” fume extraction nozzle: 100 cfm
- 3” fume extraction nozzle: 200 cfm
- 4” fume extraction nozzle: 300 cfm
Reach out to us for assistance in identifying the appropriate extractor and performance parameters for your application. For more insights on MIG welding, check out this article: Best Welding Fume Extractor for MIG Welding.
When choosing a vacuum unit, it’s important to note that the maximum advertised airflow is not as crucial as the operational airflow. The operational airflow is the airflow provided by the vacuum unit when the fume extractors (and filtration system) are active, and it will differ significantly due to pressure drop in the system.
Feel free to contact us. We will help you protect your workers and comply with welding fumes standards anywhere in the US and Canada.