What hazard is primarily associated with grinding thorium-containing tungsten electrodes?

• A. Chemical burns
• B. Radioactive dust
• C. Noise
• D. Heat exposure

Answer: (B)

When you grind thorium-containing tungsten electrodes, the main hazard is inhalation of radioactive dust. Thorium is a radioactive element, and grinding the electrode releases fine thorium oxide particles into the air. If these particles are inhaled, they can expose you to radiation internally, which is the primary risk here. This is why dust suppression and proper respiratory protection are crucial, more so than the other potential issues like chemical burns, noise, or heat. Use wet grinding or local exhaust ventilation to keep dust down, wear a suitable respirator, and consider safer non-thoriated or alternative electrode options if possible.