Welding fume extraction – challenges and opportunities
The Complete Guide to Fume Extraction
When it comes to controlling air quality, welding fume extraction is becoming increasingly important in industrial production. Welders and other employees in the production hall are exposed to these dangerous fumes, which can even cause permanent damage to health, such as cancer. Everyone must be protected from welding fumes. The regulations for this have become even stricter. But where do you start when dealing with this topic for the first time? What can be done to ideally collect welding fumes at the source of their origin and prevent them from spreading? And what options are available?
Download the free eBook that covers the various options available. Get information on the key performance metrics and the most effective method of fume extraction at the source, called spot extraction. This eBook is aimed at Management, Production Managers, Safety Officers, Health and Safety Representatives and welders alike. It is a very helpful resource for everyone - whether you are new to welding fume extraction or would like to find out more about the innovative fume extraction technology. This eBook will give you a comprehensive overview of the challenges and opportunities of welding fume extraction - and you will be ahead in the topic of active health protection.
... or scroll down to read the complete guide.
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- About the author
- Introduction
- What is your current welding process?
- What metals are you currently welding? Does it matter?
- Do you have to change your current welding support for fume extraction?
- Do you have to buy new equipment for fume extraction?
- Respirator masks
- Test fitting for your respirator mask
- Is fume extraction really that much of a health and safety improvement?
- Fume extraction welding solutions
- What are the regulatory requirements
- Fume extraction: Frequently asked questions
- Conclusion
- References
- Editoren team
Etienne Blouin
Director of Environmental Health Systems for ABICOR BINZEL USA.
Etienne has worked on implementing fume extraction welding solutions for ABICOR BINZEL for 8 years, working directly with end-users to identify optimal fume extraction measures for their welding operations. Etienne is a graduate of Université Laval with a degree in Physics Engineering.
André Faber
Head of Extraction Technology,
Alexander Binzel Schweisstechnik GmbH & Co. KG, Alten-Buseck
He has worked in the welding industry for over 15 years, first as a development engineer and then as Product Manager for manual products at ABICOR BINZEL. André is a graduate of TH Mittelhessen University of Applied Sciences with a degree in Mechanical Engineering.
So you’re thinking about making the change to fume extraction? That’s great! Your welders will appreciate it as well the rest of your employees. Fume extraction – especially at the source – has been one of the more interesting and health conscience welding concepts to come around in quite a while, and with occupational health and safety only becoming more demanding from governing bodies around the world, you might want to get ahead of the game as much as you can while protecting your workforce at the same time.
What fume extraction is
Fume extraction is the removal of fumes – either via welding, cutting, or grinding, from the work area to keep them from being inhaled by workers. The most common generation and extraction of fumes comes from welding as a result of the process – gas and current mix with a filler metal to produce fumes at the arc.
Some fumes are very visible, others less so – even if they are there. Factors like welding parameters, wire, gas, and base material all impact the thickness and prevalence of fumes in the weld shop.
No matter how visible fumes are, they are definitely being generated and your workers are being exposed to it.
Why fume extraction is for you
In truth, fume extraction is for anybody doing welding in any way, shape or form. Whether you are just learning the trade in a school, running a small shop doing repair work or run a large scale fabrication outfit, fume extraction solutions large or small, simple or complex, exist to remove weld fumes from the worker environment.
Fume extraction isn’t just a workplace environment benefit, it is also protecting your workers and company from serious health risk. A 2019 cohort analysis study in Occupational and Environmental Medicine looked at over 17 million welders worldwide from Germany to France to the United States and found that welders and people exposed to welding fumes were 43 percent more likely to develop lung cancer.
With risks like that becoming more apparent and more research being done to truly grasp the effect of welding fumes on industrial workers long-term health and safety, governments and companies now more than ever either are or will be looking at fume extraction as mandatory methods of protecting the workforce.
When it comes to fume extraction, there is a lot of taboo and bad information. In truth, it’s really a lot easier and more cost-effective to introduce fume extraction into your plant than you think. And, what’s better, you won’t sacrifice performance to get there.
This guide is going to walk you through exactly what you should be aware of and will want to know as you look at fume extraction for your welding operation.
What is your current welding process?
Lots of people worry that integrating fume extraction into their welding operation will negatively impact it. That’s not the case. You will find as you talk with people who have started to use fume extraction in their plants that they haven’t had to alter any of their current welding procedures or positions to accommodate it. The things that do impact your decision have more to do with what you weld than how you do it.
What metals are you currently welding? Does it matter?
The quick answer to that is that is does matter. All metals release different contaminants to the air as you weld.
Metals like stainless steel – which contain steel iron, chrome, nickel, and manganese, are extremely hazardous welding fumes for your welders to breathe in. You may need to get a specialized fume extraction system to safely collect and dispose those kinds of contaminants.
Anything involving chrome or nickel extraction should be IFA-W3 certified. Hexavalent chrome is the most harmful particle released into the atmosphere when you are welding, with a +6 valence state. It’s present in all stainless steel and is a known cause of cancer per several standards, studies, and findings. Having an W3 licensed extraction system that can remove these harmful elements when the CrNi content is above 30% is a very important consideration.
The FES-200 W3 is certified by the Institute for Occupational Safety (IFA) and therefor authorized for use at high-alloy chrome-nickel steels.
Our FES-200 W3 was developed specifically to meet the demands of chrome and nickel material joining, and is certified by the Institute of Work Safety with the W3 license for all welding applications or related procedures with emissions suitable to KMR / 1.2 materials. Thus, this device enables the filtering of the exhaust and work to be conducted without these otherwise harmful effects.
| Fume Class | Separation (%) | Application |
|---|---|---|
| W1 | ≥ 95 |
Non-alloyed steel, alloyed steel with alloy components e.g. Ni and Cr, low-alloyed steel, x ≤ 5% |
| W2 | ≥ 98 |
Same as W1, plus alloyed steel with alloy components e.g. Ni and Cr (5% ≤ x ≤ 30%) |
| W3 (possesses the highest separation grade) | ≥ 99 | Same as W2, plus alloyed steel with alloy components e.g. Ni and Cr (highly alloyed steel with x ≥ 30% Ni-based alloys) |
Galvanized steel is also a dangerous metal for welders to intake and is another metal that is a great fit for fume extraction because of the harmful fumes released. In galvanized steel, the alloyed properties creating that metal include iron and steel with a zinc coating. When zinc is welded, for instance, it releases zinc oxide fumes, which like exposure to manganese, copper or beryllium, can cause fume metal fever, which damages the respiratory system. Other metals like lead, which can be used like zinc as a coating on certain metals, can even damage your central nervous system.
Often, aluminum is welded with push-pull torches because the wire is very soft in its texture compared to steel wire. In fact there is still no push-pull torch with integrated fume extraction, but you can ideally equip this with our fume extraction kit (RAS). This is simply clamped on the toch neck and the gases can also be sucked at their source.
Using Push Pull MIG torches for welding aluminum is nessesary because the sophisticated wire feeding system cannot accomodate a fume extraction cable or shroud so far.
Integrating fume extraction into your existing workplace is easier than you may think.
Do you have to change your current welding support for fume extraction?
Fortunately for you, the answer is no! You can use the same procedures, protocols and systems you were previously using in your MIG welding operation and seamlessly integrate fume extraction into it.
A general rule to follow is: The higher the amperage used the more you will release welding fumes into the welder atmosphere. Likewise, some welding processes create more fumes than others.
Do you have to buy new equipment for fume extraction?
Yes. But that doesn’t mean the welding parameters or setup is changed. You would have to look into purchasing a fume extraction system and a fume extraction torch to make the full commitment and develop an engineered solution, as is typically recommended. Otherwise, there’s no change to the way you currently weld that you’ll have to do other than introduce and use the right equipment for capturing those harmful welding particles.
If fume extraction at the source is not a viable option with a fume extraction torch, fume extraction arms are another source capture route to go that will improve air quality for your welders and staff. As a complementary piece to an extraction arm, respiratory masks can give additional coverage and protection for your welder. Ideally, however, you want to take action as close as possible to the source to prevent weld fumes from spreading. The more localized, the better.
When choosing a respiratory mask, at least in the United States, it must be approved by the National Institute for Occupational Health and Safety (NIOSH). Typically, when dealing with welding fumes, you will consider either half-mask respirators, powered-air-purifying respirators, and supplied-air respirators (SAR). When using these types of masks, remember that cartridges and filters have to match the contaminant it is protecting against and be changed periodically.
Respirators are also typically last resort solutions and need to be used when engineering control systems – like ventilation control through fume extraction torches and systems, are not feasible, per the Centers for Disease Control. Reason being is while they may be more cost-effective alternatives to combating welding fumes, they are best utilized in combination with an engineered solution and not as the sole means of protection against hazardous fumes.
Test fitting for your respirator mask
When using a respiratory mask, consider fit-testing to ensure the snuggest fit possible, and checking to make sure your welder doesn’t have any heart or lung conditions that could make wearing a respirator dangerous. OSHA, in fact, has a mandatory medical evaluation questionnaire for OSHA Respirators, so make sure your welding operators complete this before fitting them with a mask.
Is fume extraction really that much of a health and safety improvement?
Absolutely. The health improvement using fume extraction is undeniable. One study from the University of North Carolina found manganese concentrations reduced by up to 50%, so the health improvement for the welder can be quite significant. Even the most modest of results in this study showed a 20 % reduction in manganese concentration.
Results are always dependent on the metal involved, the welder position, and the weld in question (whether it’s inside, outside, in an enclosed space, etc.).
How much of an improvement will always depend on the equipment investment made and the types of metals welded. It also depends on placement – where the fume extraction system is placed relative to where the welder breathes.
Often this is done in error and fume extraction as a result is not as effective as it otherwise could be because the welder is positioned in the plume.
Fume extraction welding solutions
First, let’s reiterate that no matter what fume extraction system you choose, you don’t have to change your welding procedure or welding machine. The only change you will be making is using a new welding torch and utilizing a fume extraction system – whether centrally located or portable/mobile – to have fume extraction in your operation should you decide on a source capture solution.
The welding positions your welders currently perform won’t change and the welding procedures you currently have in place will not need to be altered just because you’re using fume extraction. It’s a very common concern among those considering the switch, but we can tell you from our years of introducing fume extraction solutions to a variety of end users that none of them have had to change their positions or their operations to accommodate it.
Here we will cover each of the options you have at your disposal for fume extraction, their pros and cons and what considerations you should make for each.
Whether centrally located or portable, there‘s a fume extaction system that‘s suitable for your current work welding process & workplace.
Fume extraction torches (source capture)
Fume extraction torches look and feel bigger than normal MIG torches because of the design. First, there’s the hose that’s needed to extract the smoke. Second, the nozzle and the fume shroud on the front end also can give a bulkier handle than normal MIG torches. This tends to turn off welders at first glance, but chances are there is a fume extraction torch out there that meets your welders’ demands. Research the market to find the best torches available. Some have smaller nozzles, smaller grips, better ergonomics, work well in corners and hard to access areas, etc. Some are also lighter in weight. Weight is a huge factor in considering fume extraction torch.
You want to make sure the torch you select has three things going for it: The torch is going to be as light and comfortable as possible, the torch extracts smoke properly and it allows the welder to access the same welding positions as before.
For welder access, typically the feature of a fume extraction torch to look at most closely is the torch neck angle. The better and more natural position the welder is able to take the more comfortable he will be and the more smoke will be captured.
Whether the welder prefers a torch with a 45-degree or 60-degree neck angle, at the end of the day it‘s down to personal peference.
Comparison of a fume extraction torch with a 45-degree & 60-degree neck angle.
Comfort is such a big consideration to make because ultimately the effectiveness of fume extraction torches will be reliant on the welders’ willingness to embrace them as the tool of choice. That’s not always an easy sell, but fume extraction torch manufacturers have gone to great lengths to add more comfort and reduce weight and stress on fume extraction torches without compromising performance. Some of these improvements include ergonomic handles and swivel designs on the cable for freer wrist movement. The idea behind this is to make fume extraction torches easier to maneuver.
Typically fume extraction torches used to be heavy because of the cable weight and the handle.
The ABICOR BINZEL 300 amp fume extraction torch has a hanging weigth advantage of up to 27 %.
A fume extraction torch’s ability to capture fumes effectively is very dependent on the hose design of the fume extraction torch. This includes the hose diameter and limiting the restrictions inside the hose to allow smoke to move freely from the shroud to the extraction system. Ideally all fume extraction torches would have very large hoses that would leave no air restrictions and allows smoke to pass through easily. But that involves comfort tradeoffs on the welder ergonomics, so there is compromise between the two. The typical hose diameter you will see in the industry will be 1.25 inch (32 mm), with some makers going as high as 1.75 inch (44 mm) to try and improve flow. From our experience, any house diameter beyond 1.5 inch will typically be too cumbersome on the welder to use on a consistent basis.
Extraction hose, connected to a fume extraction unit, creates the vacuum pressure on the back-end of the torch.
The hose diameter on a fume extraction torch is crucial to how effectively the it captures welding fumes.
Flow through a fume extraction torch is measured and applied by connecting vacuum pressure on the back-end connector of the torch and put as much air flow through the fume extraction torch front end as possible. The big debate among fume extraction users who utilize a welding solution is how much flow does the fume extraction torch and vacuum system need? The answer to that is as much flow as possible without compromising the process – mainly the shielding gas. This goes back to the earlier evaluation criteria of shroud design and placement – for example, the closer the shroud is to the process, the more flow it will be able to take because if too much air is being suctioned that close to the process, then shielding gas will be captured by the fume extraction torch and cause weld porosity.
Welding torch consumables – where the value lies
Also look at your consumables. The better the consumable, the more value you will get out of the torch. Consumables with tapered front ends, for instance, would always be preferable because of the ease of maintenance and improved access. You also will experience less spatter build up because coarse threading resists binding and stays concentric with the tip holder.
Also look for the quality of the consumable. Copper, chrome, silver and nickel all are considered high grade consumable materials. And the more malleable the metal the better the performance.
Shroud design and placement in relation to the nozzle is also a very important evaluation feature for fume extraction torches. The shroud is what gives the fume extraction torch the ability to capture smoke and is where the vacuum system is suctioning from on the welding torch.
Shroud position is important because a shroud that’s too close to the process can cause porosity from causing gas turbulence, while a shroud too far removed from the process won’t capture smoke effectively. The shroud openings are another consideration to make. Larger shroud openings and shrouds with enveloping designs – think of umbrellas – are very effective shroud designs for capturing weld fumes without causing turbulence in the gas column.
For optimum fume extraction, the positioning of the fume shroud is very important. Too close to the weld and it can cause porosity. Too far back and it won‘t capture any welding fumes.
How do you test a fume extraction torch against your current MIG torch?
We recommend a simple comparison test. Take a normal MIG torch and weld regularly to see the current level of smoke being emitted. Then, try the fume extraction torch in the same position welding the same piece and make sure it can do what you want. If you want to try out different fume extraction torch, go for it! Then, choose the one that extracts the smoke better. You’ll be able to literally see the difference, as the better fume extraction MIG torches remove the fumes right at the arc.
WITH fume extraction – The harmful welding fumes are extracted through the torches fume extraction nozzle.
WITHOUT fume extraction – Welding without an extraction system fills the workplace with harmful fumes.
Fume extraction welding solutions
Robotic welding fume extraction
Health hazards created by welding fumes and the associated safety problems of affected workers can also be prevented in automated welding processes – notably robotics. With welding fume extraction in robotic welding, there are several methods available for manufacturers looking for comprehensive solutions.
Conventional robotic fume extraction application
Conventionally, the use of fume extraction in a robotic application involves some method of enclosing the robotic weld cell, configurating some sort of ducting grid and exhausting weld fumes to a collector unit within or outside the plant.
For manufacturers who weld large customized parts or need to use an overhead crane in order to lift out parts, these methods aren’t possible and normally the best option is to utilize fume extraction solutions that have to recirculate air throughout the plant. While this is possible and sometimes seen as an acceptable solution, weld fumes are still passed through the plant and workers are exposed with little means of avoiding it.
All of these solutions are likewise significant plant upgrades in order to accommodate. Significant investment in ducting and air filtration equipment plus possible reorganization of the shop floor is required to accommodate a fume extraction retrofit of such magnitude. Unsurprisingly, not all manufacturers can afford the amount of retrofitting, downtime and plant equipment all at the same time.
Source capture robotic fume extraction
However, other such solutions do exist. For instance, the use of a single fume extraction unit can cover several workplaces and ensure protection against welding fumes for several workers. When possible, the fume extraction should be directly at the source during welding. By extracting the welding fumes immediately during the welding process, there is no possibility of the welding fumes rising and damaging the health of the workers in the plant.
Example of on-torch extraction on a robotic welding torch.
An extraction system consisting of an extraction kit attached to the robot torch and connected to an extraction unit collects the welding fumes with such an enormous vacuum that no harmful gases can escape.
One of the notable differences from robotic fume extraction to manual fume extraction is when doing extraction at the source the static pressure requirements are far different. Reason being is there are far less obstructions within a robotic fume extraction setup compared to a manual. With manual welding fume extraction, machined parts, cables, hoses, and fittings all work to restrict the flow of smoke from the neck of the welding torch to the back end connect into the extractor unit.
With robotics, you are installing an extraction kit separate from the welding torch cable, meaning there are no obstructions that restrict the flow of smoke to the extraction unit. This means that while in manual welding for fume extraction it is necessary to pull at least 50 inches of water column in order to adequately capture the smoke, for robotic fume extraction as little as 20 inches of water column can collect >95 % of the weld smoke at the source and save your workers from having to inhale weld fumes.
Source capture robotic fume extraction advantages
The clear advantage for an at the source robotic fume extraction solution is that the system is a lot smaller, a lot less expensive to build, and a lot less cumbersome. With an extraction unit at the source you don’t need a big cage around it, which allows not only for a significant amount of cost savings but also for the system to be a lot more flexible, especially when welding big parts.
In robot cells, longer distance gaps often have to be bridged. Several robot torches, each equipped with an extraction kit, can be connected to a centrally located fume extraction system. This method is perfect for reliable, accessible, and safe extraction during MIG/MAG welding at several workplaces. This type of fume extraction is used, for example, in the general manufacturing, heavy mechanical engineering, construction and industrial energy applications.
Just as in manual welding, fume extraction does not disturb the welding process in a robotic welding area. In certain positions it can happen that when welding fumes are extracted, shielding gas is also extracted from the welding process. In the worst case, this can mean porosity in the welding seam. To prevent this, the extraction performance must be adjusted. Especially in the case of direct extraction, the reduction of the extraction power is the only way to avoid pores in the welding seam.
High vacuum vs. low vacuum extraction systems
Low and high vacuum systems are terms that are used often when you are consulted on fume extraction possibilities. In a robotic setting, it’s important to know the differences between the two and what one offers over the other.
Low vacuum and high vacuum systems refer specifically to static pressure. If you are able to install large ducts, you can take the traditional route with a big blower that will extract thousands of cubic meters of air through the hood. The advantage of this is because you are using a low static pressure – i.e. low vacuum – the systems are closer to what people have traditionally been familiar with through mechanically engineered HVAC system, vacuum systems, etc.
What it means in terms of fume extraction for welding is that you need high volumes of air to be moved and needing to throw the air outside means incurring an expense to take hot air in the winter and move it.
If you need to bring cold air back in the plant during the summer, there’s likewise a cost to condition air back into the plant to make up for the same amount of air you are extracting out of the plant area. The air circulated back into the plant needs to not only be fresh air but also conditioned to a thermostat setting. The cost of moving such high volumes of air, as expected, can be high month over month.
A high vacuum system uses less flow at a higher vacuum pressure. Because the static pressure and velocity of air is higher, you don’t need a big hood or arm to use a high vacuum system. Typically, you will be closer to the source of the smoke with high static pressure as opposed to ventilating a large hood with low vacuum.
This allows for smaller devices focused on where the smoke is created as opposed to large devices. With low vacuum fume extraction solutions in an automated setting, you are using large systems positioned further away and extracting the contaminant mixed with the air. As a result, you have to use more air and use more volume to remove welding fumes as opposed to addressing the most contaminated location of the process.
Source capture filter cleaning & general maintenance for robotic fume
Welding fume and the gases contained must be filtered so that nothing harmful ends up in the air. In robotic welding, ideally these filters should be able to clean themselves. In an automatic cleaning process, the pressure difference between the clean air side and the dirty air side is measured. If there is a pressure difference, an impulse comes and compressed air is blown in to clean the filter.
In an ideal world this process run would happen while the vacuum system is still in operation extracting fumes from an active robot cell. This is a great advantage as there is no downtime due to cleaning times for the filter. In addition to the automatic cleaning of the filter, there are other maintenance and cleaning tasks that have to be performed manually on the robot suction solutions. The extraction nozzle and the hoses should be cleaned regularly so that they do not clog. The dust drawers must also be kept clean and the carbon brushes must not be worn.
Source capture robotic fume extraction challenges
That doesn’t mean robotic fume extraction at the source is not without challenges. Mounting an extraction kit to a robot presents its own set of unique challenges. Making efficient use of the mounting provision for a 6-axis robot which allows for the extraction hose to rotate and move in relation to the cable is crucial for effective fume extraction that also doesn’t fail from time to time. Being certain the extraction hose is optimally positioned to capture the smoke is another key consideration.
Like with manual fume extraction, the design of the shroud fittings must lend themselves to capture the smoke without interrupting the process. Ensuring the extraction kits avoid causing unnecessary robot crashes and gives the robot torch front end access to the part are other critical factors to consider when looking to robotic fume extraction at the source.
Source Capture robotic fume extraction considerations
If the health of the workers is a priority and if you are interested in welding fume extraction for robotic welding, the most important key data you should request for information are the dimensions and characteristics of the equipment, the electrical data, the performance and the filters used.
With this information it is possible to connect your own welding process with the possibilities of robotic fume extraction. The installation of a fume extraction unit is relatively simple and quick and does not take much longer than 1-2 hours.
Mechanized fume extraction for hard automation
Mechanized welding systems are used in simple automation processes where it is possible to apply repeatability mainly in plate, beam or pipe welding. These systems seek to reproduce the operations performed in manual welding situations.
Mechanized systems require less equipment investment over robotic processes and are widely used in more open areas rather than closed cells. Tractors or stationary systems are used for welding joints. Another use is the application of welding on large workpieces.
In mechanized welding the welder manipulates the equipment or torch for adjustments, control and visual monitoring of welding.
In automatic welding the welder/operator is exposed to welding fumes and the use of personal protection is mandatory. Even if the environment is well ventilated, fume extraction is recommended, as in these actions the exposure of the welder is direct in addition to the passive exposure by people passing through the environment where the welding is being performed.
Automatic MIG welding torch fitted with direct extraction for maximum fume capture of above 90 %
Mechanized fume extraction practical application
Collecting fumes through exhaust arms with hood systems is used in processes where the torch remains in a static position or performs short movements.
Direct torch extraction systems are also used in the mechanized process and have greater extraction efficiency as they are positioned directly above the weld with efficiency above 90 %, performing smoke aspiration before dispersion in the environment.
Mechanized fume extraction considerations
It is important to consider clearance issues with extraction systems that are mounted onto the welding torch as opposed to being part of the tool itself. As these systems are part of the torch neck, considerations like tractor speed, for instance, don’t carry much influence on the effectiveness of smoke capture.
When using a source capture solution for a mechanized or hard automation process, you usually want to have the torch angled somewhere between 0 (or 180) and 30 degrees to optimally capture the weld smoke.
The addition of an external RAS system is also an option for fume extraction.
Fume extraction systems – central & portable
To do smoke extraction at the source with a MIG torch for manual or robotic source capture applications, you will need a high vacuum system. Whether it’s portable or central or mobile, if it isn’t a high vacuum, it’s not going to effectively collect welding particles and you’ll still be subject to the same amount of health risk as before. When we say high vacuum system, we mean high static pressure with relatively small flow, and that is in contrast to fume extraction arms, where you’ll be looking for an arm that produces very high flow with low static pressure.
The perfect pair for clean air! RAB GRIP 501 D HE & FEC portable fume extraction unit.
The most important thing to remember when looking at fume extraction system is you will need to achieve a minimum amount of power from the system in order to effectively capture welding smoke. You can have more than the minimum up until the moment the fume extraction torch begins to extract shielding gas. 50 inches of water column (12.4 kilopascal) should be a minimum baseline for your fume extraction system regardless of which type you go with, and the aim should be anywhere in the 80-90 range (20 – 22 kilopascal).
Are portable or central systems better?
The choice of a portable, central or mobile depends on need. If you have a stationary welding system, you can use a portable or singular unit. However, if you have more than one station, a central vacuum or multi-torch station is best. The central vacuum system is easier for the welder to connect to and it is easier to maintain.
Portable fume extraction systems
Portable fume collections systems are good and generally less cost if you want to install it yourself and need to move to different locations to perform welds while still needing to maintain fume extraction. However, maintenance is more frequent as a result typically.
There are a variety of portable fume extraction units available, each with its own features & benefits.
Stationary is pretty much maintenance-free for the welder and is more a plant manager responsibility. So, the welder gets to spend more time welding. Performance is more reliable and stable. Central fume collection stations almost always come with a larger motor and filter so there is less filter changing – just plug the fume extraction torch to the central system and weld. For the welder, there’s typically a lot more convenience with the central system.
Centralised fume extraction systems are expensive but relatively maintenance free for the welder.
Central systems have unlimited capacity as well – there’s no limit to the size of a central system. If you have a large plant operation with 40 or more handhelds arcs, you can get a system that can accommodate that if you want to go totally to fume extraction. There’s also less noise for the welder because the vacuum is located at a distance.
In terms of downside, the initial investment can be very expensive. But, bear in mind that central vacuums require a lot of upfront capital because of the electrical requirements, labor involved in getting it up and running, and the consultation required to introduce a central vacuum into your plant. However, after the upfront costs, it’s a far less costly option to maintain. You won’t find yourself replacing filters or cleaning them at nearly the rate you would with a portable system and because it’s fixed to a stationary location, your general maintenance is significantly reduced. Central systems also tend to age well.
Many of the options out there will last decades if not longer with minimal maintenance needs.
How much fume extraction can LEV arms produce?
If the welding fume extraction hoods are correctly positioned, they can extract up to 100 % of the welding fumes. However, that doesn’t mean the welder isn’t exposed to the welding fumes while welding. While the hood may be able to capture a very high percentage, the hood can’t always be placed between the welder and the process.
On average given welder habits, you can expect 70 % extraction of welding fumes using an introductory system such as an LEV arm. With a local extraction it can happen that welding fumes remain in a working hall and thus workers are still polluted.
xFUME® FLEX: Compact, flexible extraction solution for mobile individual workstations.
Source capture vs. localized ventilation: The trade-offs
Fume extraction arms are good examples of tradeoff between performance and health benefit. Fume extraction arms are effective when they are positioned properly. But, for them to work as effectively as they can, the hood has to be close to the weld and the welder cannot place themselves between the hood and the weld. In theory, it’s easy to use, but in practice it’s very common to see the welder between the arc and the hood breathing in the fumes before the hood captures it.
Which equipment best suits your workplace –fume extraction torches or extraction hoods?
There is a difference in percentage capture in a practical sense as well when it comes to fume extraction arms compared to source capture extraction. For instance, say you have a hood system and a source capture system and both capture around 90 % of the weld fumes.
Even with an identical rate of capture, these two scenarios are not the same, because in reality with extraction arms the smoke is still traveling through the welder’s breathing zone on its way to the arm vent unless both the welder and the extraction arm hood vent is in the proper place at all times.
Why does this happen? When the weld is large or the piece is long, the hood needs to be constantly moved closer to the weld where the arc is and has to be brought into the proper position by the welder. More often than not, the welder doesn’t stop the weld to continually reposition the arm as the arc moves because it’s not time efficient.
Fume extraction MIG torches normally work better in such a scenario. They are always at the source of the smoke because they are part of the same tool. It’s part of the welding process where the weld is occurring and is always sitting between the weld and the welder, so it’s capturing more fumes.
Central fume extraction systems generally have a flexible arm lenght between 2–4 metres.
Fume extraction arm positioning
If the hood is properly positioned and the welder uses perfect habits or is welding on a work bench, you will capture most of the smoke – more than 90 % is achievable in such an ideal scenario.
The challenge is the positioning of the flex arm as you do the job. The hood has to be in close range of the arc to capture properly. And that’s the biggest challenge of that technology.
Fume extraction arm advantages
As an extraction solution for beginners or as an entry-level solution, extraction hoods are great because of the low price and simple use. The local welding fume extraction solutions are effective without changing anything in the welding process or working environment. The air quality is improved and the welding torches previously used can still be used.
In the UK there is a regulatory which gives a fixed distance between the weld and the extraction hood of 15 cm.
A special feature of the extraction hoods and arms is that they can also be used for other welding processes like TIG or Plasma cutting. TIG welding is a very clean process in which only some gases are produced. If even these few gases should arise, an extraction hood is perfect, since other extraction solutions are rarely offered for TIG and would also not be cost-effective.
Fume extraction arm systems are also using filters. You will have to maintain and replace them to maintain extraction and filtration efficiency.
A grid in front of the extraction hood can prevent other things out of the environment from being sucked in other than the welding fumes.
If you use a light duty process you can use filters and cartridges that are not cleanable. If you have high duty process where you weld many hours a day you’d want a filter that is cleanable so that you can actually work longer without changing the filter and a filter that is more efficient for a longer time.
Extraction arm drawbacks & considerations
Because fume extraction hoods are often times entry level solution to fume extraction, please make sure that the unit you select is of good quality with efficient filters. Another is the quality of their build. It’s not uncommon to see an extraction arm unit with housing that is plastic in make; this is typically a bad sign for a portable unit because they lack the same durability as a steel constructed unit and also don’t do as well with limiting noise in the shop.
Arm mount position is similarly important. Think about the flexibility you would want to position an extraction hood. The more reach an arm is able to achieve, the better the welder will be able to position the hood vent to the correct spot. In a real-world application with larger, longer parts this still becomes difficult to execute because you depend on the welders to move the hood vent with them as they weld the part.
Positioning of the extraction hood is crucial.
Absaugarm-Systeme verwenden ebenso Filter. Diese müssen gewartet und ausgetauscht werden, um die Absaug- und Filterleistung fortwährend zu gewährleisten.
Ein Gitter vor der Absaughaube verhindert, dass andere Objekte aus der Umgebung angesaugt werden.
Für leichte Arbeiten können Sie Filter und Kartuschen benutzen, die nicht gereinigt werden können. Bei Hochleistungsarbeiten, bei denen viele Stunden am Tag geschweißt wird, benötigen Sie einen Filter, der gereinigt werden kann. Somit können Sie länger effizient arbeiten, ohne den Filter zu wechseln.
The use of disposable filters doesn‘t require cleaning of the filter and thus a compressed air connection is not needed.
Mechanical filtration systems are equipped with multiple filter stages.
Fume extraction for TIG welding
Example of a fume extraction setup when TIG welding using a fish-tail fume extraction nozzle attached to a portable fume unit (FES-200 W3)
TIG welding produces the least amount of harmful fumes compared to other forms of manual arc welding as shown in the graph below. That said, it does produce significant amounts of ozone and nitrous oxide both of which are irritant gases. Ozone is a particular cause of dryness of the throat, tickling, coughing or a tight chest especially when TIG welding stainless steels and aluminium.
Welding stainless steel: the risks
The harmful fumes created when welding stainless steel is believed to have serious effects on the health of welders and people in the welding environment. Chrome & nickel fume is highly toxic and can damage the eyes, skin, nose, throat and lungs and is carcinogenic.Because the hazardous substances that develop during the welding of aluminium materials, protective measures must be taken.
So, what are the options?
Fume extraction options for TIG
Unlike MIG welding torches, on-torch extraction isn’t currently available for TIG torches, other forms of extraction have to be used when welding high volume production with TIG especially on stainless steels or aluminum parts.The current forms of fume extraction available when welding with TIG are:
- Magnetic fume nozzles
- Extraction arms/hoods (LEV systems)
These are ideal for TIG welding especially for bench work where you aren‘t moving down long weld runs. With its funnel style extraction opening (round or fish-tail) and magnetic mounting stand, it gives the welder a great amount of flexibility as he/she is able to position the nozzle directly over their weld. These types of nozzles can be easilly connected to a portable fume extraction unit via an external extraction hose (see above illustration).
This setup is a very cost-effective solution to removing those harmful welding fumes whilst TIG welding.
Extraction arms/hoods (LEV systems)
Where companies that are welding stainless steel have adequate exposure controls available, a lot of the time these controls are not used or are used incorrectly. Reasons for this include a reluctance to regularly reposition the LEV hood as the job progresses (welding long beams) and also a common misconception that LEV can affect the weld quality such that the LEV is not used or positioned so far away from the weld that it is not effective. In the UK, for example, it is recommended that LEV hoods be at least 6 inches above the weld for it to effectively remove welding fumes. But some countries don’t have such recommendations or best practices. If in doubt, consult an industrial hygienist or your company’s Safety Officer.
They can be used flexibly at almost any manual welding workstation and for all welding, cutting and grinding applications. The extraction unit is also suitable for particularly cramped and hard-to-reach areas with poor lighting conditions and tasks where a standard welding torch without extraction is required.
What are the regulatory requirements?
Is there a national law you have to follow? A local?
In Canada, the current occupational exposure limits are determined by province. So, what the limits are for Ontario may not be what the limits for Quebec. Looking at Ontario, for example, the Ministry of Labour provides a table to use as a guide for exposure limits, and employers must take reasonable measures to protect workers from these substances. Chromium metal compounds, for instance, have a time-weighted average limit (TWA) of 0.5 mg/m3, with that TWA being 8 hours.
OSHA in the United States has several Safety and Health Regulation for welding and cutting when it involves certain types of metals or welding with certain types of gases. For instance, when welding or cutting zinc-bearing base or filler metals with zinc materials, lead base metals, cadmium bearing filler metals or chromium bearing metals, it is mandatory that a general mechanical or local exhaust ventilation system be used that keeps welding fumes and smoke within safe limits.
If the metal contains beryllium, for instance, welding would have to be performed with both a local fume extraction system and with an air-line respirator. OSHA has several guidelines for welding with certain metals and gases and we highly recommend checking their website to see what fume extraction equipment you may need to have based on what you’re welding.
Every country and even region may have its own regulations and standards when it comes to exposure limits or mandatory equipment. As we cannot provide a full overview about every regulation in every country, it is important to check for yourself if there are national or local requirements you need to follow before deciding about a fume extraction solution.
What are some of the best practices for fume extraction welding?
If you can extract the welding fume right at the source, it’s always better than any other method. The intent is always to make sure that the manganese or zinc oxide or hexavalent chromium doesn’t spread throughout the plant and become inhaled. Think of it like a virus and you’re trying to cover up a cough or a sneeze. If you can control the smoke right at the arc and get it at the source, it’s best.
You also have to protect your welder as well as others in the general area of the welder. Remember to always wear the proper personal protective equipment. For instance, wearing a respiratory mask is one way to provide an additional barrier of protection for your welder to make sure he or she isn’t ingesting smoke fumes. If you aren’t removing the fumes at the source, it’s highly recommended if not required in your area that your welder be wearing some kind of mask to protect against breathing in fumes on top of wearing eye protection.
There are also ventilator cells that filter fresh air into the welding mask to directly provide clean air for the welder to breathe while they work. If you consider this route, keep in mind that there are different respiratory masks and filters for different types of metal.
The most effective way to capture harmful welding fumes -is extraction at source. The harmful fumes generated when welding are effectively The most effective way to capture harmful welding fumes is extraction at source. The harmful fumes generated when welding are effectively captured by the outer extraction nozzle (1).
The fume then travels through the outer swan neck, the handle (2) and all the way down the torches cable assembly.
External fume extraction hose is attached to the torches housing at the machine end (3) and the other end is attached to the fume extraction unit (4) where the fume is successfully, and more importantly, safely captured.
Where can you get more information on how to make sure you’re compliant?
You should refer to your local Occupational Safety office. In Canada, for instance, every province is responsible for their own occupational safety standards, so what’s accepted in Ontario may not be proper in Quebec. In the United States, the standards are nationally recognized by OSHA, so refer to OSHA.gov for more information.
Also, if you have a safety officer in-house, consult him/her, as they should be up to date on what you need to do to be compliant. Also reach out to a Certified Industrial Hygienist who can assess your welders‘ air quality and help determine the right course of action for you.
Fume extraction: frequently asked questions
There’s usually a question of whether all that additional design and engineering that goes into these fume extracting torches affect the performance of the torch itself. Is there a loss of amperage? Will it fatigue my welder more?
We answer those concerns below.
While it is argued that fume extraction torches don’t ‘perform’ as well, the answer is no, you won’t sacrifice any performance.
Today’s fume extraction welding torches perform just as well as regular welding torches with capacities from 200 to 500 amp air and water cooled for almost every possible situation a standard MIG torch handles.
The torches also feature the same range of features as in a standard MIG torch.
If you use an industrial welding machine, such as a Millermatic® or a Lincoln® Power Mig® a Fronius, an EWM, a Lorch or a welding machine of similar amperage rating and capacity a fume extraction torch is easily configurable for such a machine. Any Euro-style machine can also be easily fit to a fume extraction torch.
The only types of machines that would be difficult to fit a fume extraction torch on would be a portable style or hobbyist welding machine.
The durability of outer hose varies. It ranges. But it is a special material that is resistant to heat spatter and UV. Eventually it will need replacement like all welding cables, but it does hold up to the normal industrial environment. There are extra protection covers you can use to put over the outer hose as well to give it extra life and protection.
Fume extraction torches have been really sensitive to creating porosity from the vacuum sucking up the shielding gas and replacing the gas with oxygen. This in the past has caused a lot of bad welds and a lot of reworking, work which undercuts the investment into fume extraction torches and extractor systems.
You want to make sure all the vacuum you apply is not reaching the zone where the shielding gas should be. If you measure turbulence near the end of the shielding nozzle, then your flow is too strong or your shroud too close the welding operation.
This was a common issue with the first generation of fume extraction torches. In order to fit all the additional components into the first fume extraction torches there was a significant amount of added weight that made the torch bulky, heavy and cumbersome to handle.
Today, with a much-increased focus on weight reduction, welder access and torch ergonomics, modern fume extraction torches are far more comfortable and welder-friendly tools. So much so, that some, including our own xFUME™ / RAB torch line, are actually less in weight than comparably rated, non-fume extraction torches.
Weld.com has a great YouTube video that covers the fume extraction weight question.
This is a great question, because there are fume extraction torches that can be heavy and bulky to handle, which can affect welders’ stamina. But, even the strain of using a fume extraction torch would depend on the torch you’re changing from and the smoke torch you’re picking, because there are fume extraction torches out there that achieve the same feel and handle as most MIG torches on the market.
It’s also a matter of welding positions. Overhead and vertical welds by their very nature are more straining weld positions than horizontal or down welds, so heavier fume extraction torches could be more strenuous and adversely affect performance because if the torch isn’t positioned properly it won’t capture the fume as much as it could. However, these concerns and the torches’ performance again depends on the MIG torch being switched from and the fume extraction torch in question. Take a demo and see if the difference is real.
You can find plenty of MIG torches out there with the swivel at the base of the cable and there are plenty of cables out there that weigh the same as many non-fume extracting MIG torches on the market. Do your research and talk to your welding supplier or a qualified rep.
The only additional consumable a fume extraction torch requires is the fume shroud. Other than that, you’re using the same setup as a regular MIG welding torch: diffusor, tip holder, contact tip and nozzle.
Consumables such as the diffusor, tip holder and contact tip are the exact same for regular ABICOR BINZEL MIG welding torches as our fume extraction torches. And for most other manufacturers it also the same.
In short, no. Fume extraction torches handle any wire – whether flux-cored, metal core, or solid wire. However, depending on the wire used there can be more smoke produced, which is a consideration and an item to evaluate as you look at all the options with fume extraction solutions. With metal core and solid core, you will be looking at higher parameters normally as well as hotter gas mixes, which will translate to faster traveling smoke and more difficult welding positions to do fume extraction with for a source capture solution.
Metal core presents one of the common misconceptions of fume extraction welding. For some, it is believed that welding metal core wire with a clean gas mix (i.e., CO2) creates a ‘clean’ smoke that doesn’t need fume extraction. This is a common myth. Toxic particles will still be released into the atmosphere from the base metal and from the wire as it melts to join into the weld joint and without proper fume extraction equipment and procedures in place, your welders and the rest of your workers will breathe it in and be adversely affected by it.
Flux-core wire produces a very thick and visible smoke when being welded with. It also releases a lot of particulates into the atmosphere that you would want to catch at the source so as it wasn’t breathed in by your workers. Flux-core is also generally used for low parameter welding, which makes it very easy to extract at the source because lower parameter means slower smoke travel.
Filter life on fume extraction systems is tough to predict. Systems with a cleaning device will typically last between 6 to 12 months. For systems with no automatic cleaning process, it’s very dependent on the filter size, the welding wire used, base metal and the parameters of the welding machine. For instance, high vacuum systems without an automatic cleaning system can need filter replacement after as little as two spools of flux-cored wire.
On LEV systems the filter is most of the time not monitored automatically, so there is no signal, whether the filter is full or not. How long the filter lasts depends on the duty cycle, the welding process, the material welded, etc. As a rough calculation you can say that if you’re using the LEV 3-4 hours a day the filter has to be changed one time per month.
Regardless, it’s important to monitor the efficiency of the fume extraction system. If you find it is not adequate, the filter is one of the first things to check. Some systems have sensors or gauges built in that will activate when the differential pressure in the filter is too high, which lets you know you need to replace the filter.
Any fume extraction arm would be in the range of 1000 – 1200 m3/h flow. Some arms go lower. These systems will ideally have higher flow and lower static pressure compared to solutions you would pair with fume extraction torches. Remember with fume extraction system flow is the key performance metric.
Portable fume extraction systems are measured on static pressure moreso than flow. For a portable fume extraction system, the typical range is anywhere from 60 – 100 CFM (102 - 170 m3/h.
An important item to consider is that the flow mentioned in most product catalogs assumes zero restriction, which is not a solution based in the real world. There is no good and simple answer for what your flow is going to be once you connect a fume extraction torch to the system. These results typically sit on a flow curve.
Since the torch is typically a very restrictive tool, keep in mind you will need a unit able to produce a high static pressure to overcome a torch’s restrictions.
Yes, some systems do offer adjustable or dual-flow set-up. Check with whichever company you consult with on fume extraction solutions to see if they offer it.
Fume extraction units for ABICOR BINZEL fume extraction systems do have an adjustable flow feature.
Conclusion
Today you want welders to be in a safer, healthier environment. Healthier welders mean happier welders, which fosters better performance for your operation.
There have been a lot of options introduced to the market for fume extraction and there are many ways to introduce fume extraction into your plant no matter the number of arc stations you have or the budget you’re able to dedicate towards it. If you’re still skeptical, ask your welding supplier to provide you a demo or a trial with a fume extraction torch in your own work environment and see if there’s a difference.
It’s no risk!
Chances are you’ll be surprised, and may look at fume extraction in a whole new light.
References
Rapaport, Lisa: More evidence welding fumes raise lung cancer risk ; reuters.com, 21. Mai 2019
Prüfstelle des Instituts für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung (IFA)
https://www.dguv.de/ifa/pruefung-zertifizierung/index.jsp
Schweißtechnische Arbeiten, Technische Regel für Gefahrstoffe
https://www.baua.de/DE/Angebote/Rechtstexte-und-Technische-Regeln/Regelwerk/TRGS/TRGS-528.html
Chrom – eine Frage der Wertigkeit; Umweltbundesamt
https://www.umweltbundesamt.at/umweltsituation/schadstoff/chromat/
Welding – Fumes and Gases; Canadian Centre for Occupational Health and Safety
https://www.ccohs.ca/oshanswers/safety_haz/welding/fumes.html
Safety and Health Regulations for Construction – Welding and Cutting; Occupational Safety and Health Administration (OSHA)
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10699
Respirators; The National Institute for Occupational Safety and Health (NIOSH)
https://www.cdc.gov/niosh/topics/respirators/
Occupational Safety and Health Standards – Personal Protective Equipment; Occupational Safety and Health Administration (OSHA)
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9783
Kompatibilität von Atemschutzgeräten; Das Atemschutz Lexikon
https://atemschutzlexikon.de/recht/kompatibilitaet-von-atemschutzgeraeten/
Richtlinie für die Grenzwerte zur Exposition von Schweißrauch
https://www.labour.gov.on.ca/english/hs/pubs/oel_table.php#c
Flynn, M. R.; Susi, P.: Local Exhaust Ventilation for the Control of Welding Fumes in the Construction Industry – A Literature Review, Oxford University Press, 2012
http://annhyg.oxfordjournals.org/content/56/7/764.full.pdf+html
Verordnung zur Arbeitsmedizinischen Vorsorge (ArbMedVV)
Honaryar, M. K.; Lunn, R. M.; Luce, D.; et al.: Welding Fumes and Lung Cancer – Occupational and Environmental Medicine; Meta- und Kohortenstudie, 2019
https://oem.bmj.com/content/76/6/422.info
Fume Extraction Gun Myths, Weld.com
Editorial team
We hope that you enjoyed this e-book and that your expectations have been fulfilled. Your suggestions and comments are always welcome.
Many people have contributed to this e-book, in particular:
Alexander Binzel Schweisstechnik GmbH & Co. KG, Germany
- André Faber, Head of Extraction Technology
- Jan Hasselbaum, Director Marketing International
- Herbert Burbach, Art Director
- Katharina Röschegg, Digital Communication
- Barbara Heuser, Marketing
ABICOR BINZEL UK Ltd.
- Danny Seddon, Marketing Manager
ABICOR BINZEL USA, Inc.
- Etienne Blouin, Director of Environmental Systems
- Tyler Caudle, Marketing Specialist
- Matthew Sciannella, Director of Marketing
BINZEL DO BRASIL
- Andre Geronymo, Marketing Supervisor
- Mayara Ferreira, Marketing Assistant
BINZEL MEXICO
- Grecia Rubio, Marketing Specialist