Which fumes are especially hazardous when welding stainless steel, and what controls minimize exposure?

• A. Fumes containing hexavalent chromium and nickel.
• B. Ozone produced by UV light.
• C. Dust from grinding.
• D. Carbon monoxide from welding.

Answer: (C)

The key idea is that the most hazardous fumes from welding stainless steel are those that contain hexavalent chromium compounds and nickel compounds. Stainless steel often includes chromium and nickel, and when it’s welded these elements can become part of welding fumes. Hexavalent chromium is a known carcinogen and can cause serious respiratory and other health effects, while nickel compounds can irritate the lungs and also pose cancer risks. Because of these risks, controlling exposure focuses on capturing fumes at the source and keeping the worker environment well ventilated.

To minimize exposure, use engineering controls that remove fumes right at the arc—local exhaust ventilation or a fume extractor positioned as close to the weld as possible—combined with good general ventilation to dilute any remaining fumes. Ensure these systems are properly maintained and used consistently. If after leveraging proper ventilation the exposure risk remains above acceptable limits, implement appropriate respiratory protection and other protective measures as part of a broader exposure control plan. Dust from grinding and ozone from UV light are separate hazards and not the primary hazardous fumes produced by welding stainless steel, though they may require their own controls in different contexts.