Non-Radioactive. Best for automated or robotic applications in alternating current (a/c) or direct current (d/c) due to low voltage tolerance (changes in tip to work piece distance) using inverter or transformer based constant current power sources. Good for low-alloyed steels, Non corroding steels, aluminum alloys, magnesium alloys, titanium alloys, nickel alloys, copper alloys. very stable tip geometry, runs cooler than 2% thoriated with longer life, low to medium amperage range. very best low amperage starts. Package of 10 Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.