-
What could happen?
Tungsten electrodes are used when arc welding or plasma welding.
The most common thoriated tungsten electrodes contain 2% thorium, are coded WT20 and have a red tip.
Thorium is slightly radioactive with a long half-life and emits mainly alpha (α) particles, but occasionally some beta (β) and gamma (γ) radiation.
Alpha particles cannot penetrate skin or even paper. However, they are harmful if released inside the digestive tract or lungs, where they act as a carcinogen.
-
Potential risks
Although the risk to the welder is very low (negligible), the risk is higher when thorium is ingested or inhaled.
There is little release of radioactive material during arcing and welding operations.
The main risk is from grinding the electrode (it is conically ground before and during use).
-
What can we learn?
In some countries the manufacturing, sale or use of this type of electrode is forbidden or strictly controlled.
Consider an alternative. Ceriated or lanthanated tungstens are acceptable alternatives to thoriated tungstens, particularly with a DC current, while zirconiated tungsten is preferred for AC current welding.
During grinding, dust extraction equipment has to be used and respiratory protection must be worn by the operator.
-
Ask yourself or your crew
What are the local standards/practices for tungsten electrodes use?
Are we currently using thoriated tungsten electrodes? Is there some way we could not use tungsten electrodes and replace them with a safer option – eliminating the hazard from the start?
What PPE is required when grinding and welding using thoriated tungsten electrodes?
How can we make sure everyone wears the PPE, including breathing apparatus?
Add to homescreen
If you want to add this app to home screen tap and then ‘Add to Home Screen’.
Content name
Select existing category:
Content name
New collection
Edit collection
Published on 05/07/19
4780 Views
Thoriated tungsten electrodes used when arc welding or plasma welding emit radioactive particles, which present a negligible risk to the welder if they come in contact with the skin, however they become harmful if released inside the digestive tract or lungs, where they act as a carcinogen.
