PREVENTION LINE Complementary Welding Fume Mitigation Using Specialized Gases

Arc welding processes bring unique advantages to metal fabrication value chains but also have long been known to emit potentially hazardous welding fumes. These have been associated with various occupational safety and health threats. Aside from the obvious exposure risk to individuals, emissions also pose a risk to the industry. If left unaddressed, welding may become stigmatized - making a redressing of the current labor shortage even more challenging. According to a 2024 EURES Report, 23 European countries reported a shortage of welders and flame cutters with 35% of those classifying it as a "high severity shortage". The time to tackle the welding fume emission challenge is now - and Linde is in a leading position to help do so.

"From extensive R&D activities under our REarc program (Reducing Emissions in arc welding), we know exactly how fumes are generated at source in the welding arc," explains Ernst Miklos, Linde Fellow and REarc initiative lead. "We also know what role gases play, so our intention is now to lower those emissions through specialized gas compositions,".

A split-screen comparison of fume emitted by GMAW/MAG welding carbon steel

Taking on Emissions at Source

The name itself doesn't do justice to the role of gases in so-called Gas-shielded Metal Arc Welding (GMAW) - the metal joining technique whereby forward-fed filler wire is melted into a molten pool in an electric arc. The gases do so much more than simply shield the arc from air: the mixture directly influences arc behavior, electrochemical reactions and the fume emission rate (FER). Optimizing that blend of gases therefore holds the key to targeting lower FER, without compromising on productivity (at the same wire feed rate).

A graph plotting welding fume emission rate versus argon content in welding gas

Here, it is important to note that the vast majority (up to 98%) of welding fumes come from overheating this filler metal in the arc which then evaporates. While some of these generated metal vapors enter the molten pool or condense at the component surface, a share of vapors leaves the hot arc zone as a result of thermal gas expansion. They subsequently cool down and re-condense in the atmosphere where welders and other workplace bystanders are at risk of exposure.

Today, the majority of welding enterprises use gas mixtures containing 15-25% CO₂ (in Argon) for GMAW (MAG welding) of carbon steels. Through years of testing different gas mixtures for this predominant arc welding application and measuring emissivity under carefully controlled conditions defined by industry standards, Linde's work has documented that by increasing the Argon content of welding gases, it is possible to achieve lower Fume Emission Rates (FER). "Simply put, the amount of CO₂ influences the heat distribution on the melting wire tip in the arc," explains Miklos, "The less CO₂ in the gas, the less the molten filler tip overheats in the arc, and the less fumes emitted," he adds.

Metallic, welded cubes visualize the S.T.O.P hierarchy of controls recommended for OSH in welding.

S.T.O.P: In the Name of Workplace Safety

In efforts to control exposure to workplace hazards (including welding fumes as potentially hazardous substances) Occupational Safety & Health (OSH) authorities recommend implementing a regulatory logic known as the "hierarchy of controls". This ranks protective measures according to their effectiveness, indicating a preferential way of selecting or combining actions which will best control exposures, under the specific conditions of any one workplace.

Disclaimer re. Test Results

All fume emission rate (FER) data was generated according to industry standards (e.g. ISO and AWS) and are provided for reference and comparison purposes only. FER is only one factor affecting workplace air quality. Your actual welding conditions, materials, processes and methods will also affect workplace air quality and the welder’s exposure levels. Users and employers have the sole responsibility for and control over workplace conditions, including the manner in which work is performed and the safety measures taken. Always read and follow all information on product labeling and safety data sheets when using Linde products. Safety data sheets for Linde products, including references to other important and helpful information specific to your location, can be found by visiting your local country website.If you have any questions about reducing or controlling welding fumes, or complying with applicable standards in your workplace, you should consult with a qualified industrial health professional who can assess your unique circumstances and provide customized advice about the options available to you.

Disclaimer Of Warranties

Because every welding environment is different, Linde does not warrant that customer’s use of its products will duplicate the FER set out herein since this data was produced under laboratory conditions and in line with applicable industry standards. Linde expressly disclaims any and all warranties, aside from those (if any) Linde expressly makes in writing for a particular product sold to a particular customer. Linde expressly disclaims any and all implied warranties, including any implied warranty of merchantability or any warranty of fitness for any customer’s particular purpose.

Close up photo of Gas shielded metal arc welding torch, welding arc and molten pool.

Offering Customers a PREVENTION LINE^™

Linde's arc welding customers want and need to comply with occupational exposure limits but cannot afford to compromise on productivity or quality, since these are decisive for their competitiveness. By understanding both customer needs and the impact of gases on arc welding, Linde can now offer its customers a dedicated product line of gas blends aimed at the reduction of fume emission rates in GMAW of carbon steels.

Beyond this, the PREVENTION LINE gases can help customers meet their carbon footprint reduction targets: using less CO₂ in the welding gas translates to lower fugitive CO₂ process emissions (Scope 1) and somewhat reduced electrical energy consumption (Scope 2). There are economic benefits too: post-weld cleaning efforts can be reduced since oxidation slags and spatters get less. Quality wise, lower CO₂ contents in the process gas will limit burn-off alloying elements from the wire, enabling better mechanical properties of the deposited weld material.

With its international industrial presence, Linde thinks globally and acts locally: the need to improve working conditions for welders is a global task, while OSH regulation, technological maturity and product portfolios are localized. In a first implementation step Linde aims to identify locally already available products and solutions to substitute welding gases with higher CO₂ content. Therefore, it is no surprise that under the PREVENTION LINE^TM customers can choose from a diversity of localized Linde trademarks, examples given: CORGON^® 8, CORGON^® 10, MIGMIX GOLD^TM, ARGOSHIELD^® Light, etc.

Linde's REarc R&D effort continues for other welding processes like FCAW and MCAW and other material groups like stainless steels and high-alloyed materials. As Miklos says, "When it comes to occupational health and safety, our work is never done."

Disclaimer re. Test Results

All fume emission rate (FER) data was generated according to industry standards (e.g. ISO and AWS) and are provided for reference and comparison purposes only. FER is only one factor affecting workplace air quality. Your actual welding conditions, materials, processes and methods will also affect workplace air quality and the welder’s exposure levels. Users and employers have the sole responsibility for and control over workplace conditions, including the manner in which work is performed and the safety measures taken. Always read and follow all information on product labeling and safety data sheets when using Linde products. Safety data sheets for Linde products, including references to other important and helpful information specific to your location, can be found by visiting your local country website.If you have any questions about reducing or controlling welding fumes, or complying with applicable standards in your workplace, you should consult with a qualified industrial health professional who can assess your unique circumstances and provide customized advice about the options available to you.

Disclaimer Of Warranties

Because every welding environment is different, Linde does not warrant that customer’s use of its products will duplicate the FER set out herein since this data was produced under laboratory conditions and in line with applicable industry standards. Linde expressly disclaims any and all warranties, aside from those (if any) Linde expressly makes in writing for a particular product sold to a particular customer. Linde expressly disclaims any and all implied warranties, including any implied warranty of merchantability or any warranty of fitness for any customer’s particular purpose.