TIG welding is considered to be a very clean welding process, as little or no welding fumes usually rise during work. But appearances are deceptive. Even though there are not much welding fumes generated, it is important not to underestimate the dangers of TIG welding. Because other factors also play a role and they make TIG extraction a good solution.
The Misunderstanding of a clean welding process
The TIG welding process is often used when it comes to high-quality and visible welds, e.g. when processing stainless steel or aluminum. Compared to the MIG/MAG welding process, TIG welding is a rather slow process that produces more steady welds and less spatter. As a result, there is comparatively little welding fume formation during the process. This leads to the often misleading claim that TIG welding is a "clean" process and requires fewer preventive measures.
But in addition to the amount of welding fume which is generated, the filler materials used, the base material of the workpieces and the choice of tungsten electrode must also be considered in order to form a complete picture of the dangers of TIG welding and take reasonable protective measures such as TIG extraction.
Base material and filler materials – Danger from carcinogenic hazardous substances
As already mentioned, the TIG welding process is often used for welding stainless steel. Chromium and nickel are the most common alloying elements in all stainless steel groups. During welding, these elements are transformed into nickel oxide and chromium (VI) compounds, which can even cause cancer in addition to respiratory irritation and damage to the nervous system. A W3-certified fume extraction unit is therefore essential when welding high-alloy steels in order to protect the welder from serious health damages.
In addition to the base material, filler metals can also be used, for example to produce additional corrosion resistance in the welding seams. These are often also high-alloy and contain chromium and nickel, which in turn increases the hazardous exposure of nickel oxide and chromium(VI) to the welder.
The following table shows which welding fume class is appropriate or necessary for which type of alloy, so you can find the right fume extraction unit for any welding job:
|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 und Cr (5 % ≤ x ≤ 30 %)|
|W3||≥ 99||Same as W2, plus alloyed steel with alloy components e.g. Ni and Cr (highly alloyed steel with x ≥ 30 % Ni-based alloys)|
Table 1: Classification of welding fumes
The tungsten electrode in TIG welding
Thorium-containing tungsten electrodes are rarely used in TIG welding nowadays, and that is for a good reason. Thorium-containing electrodes have radioactive properties. They release radioactive dusts during grinding. And when welded, fumes are generated which contain thorium oxide. Inhaling these emissions brings the risk of internal radiation exposure. Especially in TIG welding with alternating current, which is often used for aluminum materials, exposure to thorium oxide would no longer be negligible.
If tungsten electrodes with thorium are still used for mandatory technical reasons, especially during welding and prior grinding of the electrodes it must be taken care of the adequate extraction and disposal of the grinding and welding dusts.
In general, tungsten electrodes without radioactive properties should be favored. There is a large selection of tungsten electrodes with other oxide additives. An overview of all tungsten electrodes and for whom they are suitable can be found in our blog article: Practical tips for welding: tungsten electrodes
Ozone and reflections as a further source of danger in TIG welding
In TIG welding, exposure to ozone is higher than in other welding processes. This is because materials such as aluminum or stainless steel are usually welded with TIG. These bare surfaces reflect UV radiation very strongly compared to black steel, which is usually welded using the MIG/MAG process. The ozone formation occurs not only in the immediate vicinity of the weld, but also beyond it at some distance. Ozone is formed by the UV radiation of the arc from the oxygen in the air and is classified as carcinogenic according to TRGS 905 (Technical Rules for Hazardous Substances). It should therefore not be inhaled by the welder. Since UV radiation can spread more easily with less welding fumes, there is a greater risk from ozone formation with the TIG welding process than with the MIG/MAG welding process, where the generation of welding fumes is much higher. Extraction at the point of origin using an fume extraction torch is the safest alternative.
That's why extraction is a must for TIG welding
All in all, the dangers of TIG welding seem rather small at first glance, which is why they are often underestimated. But if you look at the aspects mentioned here, you can see that a TIG extraction system is important for the effective protection of the welder. There are many ways to remove welding fumes or other emissions such as extraction hoods or central extraction systems. The safest way is still the removal of fume and all other emissions at the point of origin by an extraction torch. Meanwhile there are highly developed extraction torches for TIG welding available, such as for MIG/MAG welding.
The lightweight xFUME TIG® extraction torch from ABICOR BINZEL has a combined ceramic protection and extraction nozzle. With its slim front end a good view of the welding process is ensured at all times and its shape provides perfect accessibility. Furthermore, various wear part equipments can be used to facilitate adaptation to any welding task.
The protection and health of the welder always come first. Therefore, extraction should also be a must for TIG welding. With the xFUME TIG® extraction torch, this is even possible without any noticeable restriction in handling.
More information about Fume Extraction you can find in our free eBook: