Welding fumes are notoriously toxic, and health and safety organizations constantly change the rules to ensure workers are protected. As a result, relying on general ventilation is rarely acceptable anymore, and welding fume extractors are more and more common. If you are considering buying one, I will give you all the information you need to get started.

Not only do welding fume extractors work, but they often are the only way to meet health and safety regulations. To get the best results: pick the proper extractor for your process, make sure to have the required airflow for efficient extraction, and ensure the extractor is used correctly by welders.

In this article, I will give you some information about exposure limits. You will also be introduced to different types of welding fume extractors and when to use each one of them. Finally, I will give you some guidelines to ensure there is enough airflow to get good results.

Do you need a fume extractor for welding?

General ventilation is rarely sufficient to prevent workers from breathing toxic welding fumes. In most cases, welding fume extractors are necessary to protect welders and meet health and safety rules. This is true for every welding process: MIG/GMAW, TIG/GTAW, Stick/SMAW, FCAW, etc.

In the US, OSHA has established the following Permissible Exposure Limits or PEL (weighted average concentration of a substance in the air over 8 hours inside the welder’s breathing zone):

  • Welding Fumes for iron, mild steel, or aluminum: 5 mg/m3
  • Hexavalent Chromium (mostly in stainless steel welding fumes): 5 μg/m3

Some substances sometimes found in welding fumes also need to be kept below their own PEL. It is especially true when welding stainless steel, cadmium, lead-coated steel, copper, nickel, or chrome. ACGIH also recommends a threshold limit value of 0.02 mg/m3 of manganese oxide in the welder’s breathing zone.

Each province or territory in Canada has established its exposure limit, usually between 3 and 10 mg/m3. Some jurisdictions also make a distinction between inhalable and respirable particles. In addition, several toxic substances found in welding fumes (such as chromium or nickel) also have their concentration limits. Consult the local Health and Safety Regulations or contact us to know more.

Here are the exposure limits for welding fumes in each Province and Territory 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
TWASTELC
ABALARAALARAALARA
BC 10mg/m3(i)*
3mg/m3(r)*
30mg/m3**
9mg/m3**
50mg/m3
15mg/m3
MB10mg/m3(i)*
3 mg/m3(r)*
NoneNone
NB 10mg/m3(i)*
3mg/m3(r)*
NoneNone
NL 10mg/m3(i)*
3mg/m3(r)*
30mg/m3**
9mg/m3**
50mg/m3
15mg/m3
NT5mg/m310mg/m3None
NS10mg/m3(i)*
3mg/m3(r)*
NoneNone
NU5mg/m310mg/m3None
ON10mg/m3(i)*
3 mg/m3(r)*
30mg/m3**
9mg/m3**
50mg/m3
15mg/m3
PE10mg/m3(i)*
3mg/m3(r)*
NoneNone
QC5mg/m315mg/m3 **25mg/m3
SK5mg/m310mg/m3None
YT5mg/m35mg/m3None

* Based on ACGIH recommendations.
** For 30 minutes during a workday.

Breathing welding fumes could cause the following health effects:

  • eye, nose, and throat irritation;
  • metal fume fever;
  • suffocation;
  • dizziness and nausea;
  • stomach ulcers;
  • kidney damage;
  • lung damage and various types of cancer;
  • nervous system damage;
  • prolonged exposure to manganese fume can cause Parkinson’s–like symptoms;
  • asphyxiation.

You can read the OSHA Fact Sheet about Welding Fumes for more information.

Fumes extractor are one of the ways to protect workers around welding operations as well, which is also very important.

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.

Henlex Inc.
1-800-922-2522
info@henlex.com

Different types of Welding Fumes Extractors

Fume extraction MIG gun

Fume extraction MIG guns are the best solution to control MIG welding fumes. They are extracted directly after the gas nozzle through the handle and a flexible hose covering the power cable. The vacuum will be provided either by a portable unit or a central system. Other than that, they work like conventional MIG guns, which means welders can work as they are used to without thinking about positioning a fume extraction device. On-tool extraction works for every weld length and position.

A case study showed that it possible to meet OSHA welding fumes PEL and the ACGIH manganese oxide recommendation with this technology. A steel parts manufacturer tested the AIRGOMIG gun over several days. An independent company was commissioned to perform air sampling according to methods and protocols recognized in Canada and the United States, the sampling filter being installed inside the welder’s helmet. The MIG gun was tested during 8-hour shifts over three days with solid, metal-core, and fluxed-core wires. The average welding fumes concentration was between 0.45 and 0.69 mg/m3 (more than five times below OSHA’s PEL), and manganese oxide was maintained below 0.015 mg/m3 (ACGIH recommends 0.020 mg/m3).

You can learn more about the pros and cons of fume extraction MIG guns here.

Fume extraction arm

Fume extraction arms are an excellent solution for every welding process. They are usually installed on walls, on the ceiling, or directly on a table and can be positioned as far as a foot or two away from the welding pool and still be very efficient. Some arms can cover as much as 600 square feet, depending on their length. Ohers are sold as portable units with a blower and filter. They need to be well positioned to be efficient.

Fume extraction nozzle

When a fume extraction MIG gun is not an option, and you need the flexibility an extraction arm can’t provide, it is possible to use fume extraction nozzles. They usually come with magnets or suction cups and should be placed a few inches away from the welding pool for good efficiency. This solution is inexpensive but requires a lot of repositioning from the welder.

Fume extraction hood

In general, fume extraction hoods cannot protect a welder as their head would be between the welding area and the hood itself. But they are perfect for robotic welding and offer an unmatched fume extraction efficiency in this case.

Downdraft table

There is a misconception that downdraft tables are suitable for welding fume extraction. But it is nonsense to extract welding fume naturally going up at high speeds from the bottom. So, either downdraft tables don’t work for welding fumes, or the airflow needed to make them efficient is cost-prohibitive. Use a downdraft table for plasma cutting or a grinding workstation, but not for welding.

The Best Way to Remove Welding Fumes for Each Process

ProcessMIG gunArmNozzleHoodTable
MIG / GMAWBestYesYesNoNo
TIG / GTAWNoBestYesNoNo
Fluxed-Cored / FCAWBestYesYesNoNo
Stick / SMAWNoBestYesNoNo
Robotic WeldingYesYes*NoBestNo
Aluminum WeldingBest**YesYesNoNo
Grinding***NoNoNoNoYes
Plasma Cutting****NoNoNoNoYes

* For a robot that welds in the same relatively small area (like a welding lathe, for example), it is possible to use a flexible arm to extract welding fumes.

** 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.

Minimum Airflows Required for Good Results

The airflow that will be needed depends on many factors, such as the welding parameters, the welding position, how close the extractor can be positioned, the welded materials, and coatings used. Nonetheless, here are some guidelines for the minimum airflow you should be expected to have 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

Contact us, and we will help you figure out the extractor and performance needed for your application. For MIG welding, you can also read the following article: Best Welding Fume Extractor for MIG Welding.

When selecting a vacuum unit, it is essential to understand that the maximum airflow advertised is irrelevant. What is crucial is the operational airflow, which is the airflow that the vacuum unit will provide once the fume extractors (and filtration system) are in use. It is very different because of the pressure drop in the system.

In the menu of this website, you will find the different welding processes. Click on the one that interests you to see which type of vacuum unit to use for each solution.

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.

1-800-922-2522
info@henlex.com