What is the role of local exhaust ventilation in welding safety?

• A. Captures fumes at the source
• B. Dilutes room air
• C. Increases humidity
• D. Reduces oxygen

Answer: (A)

Local exhaust ventilation captures fumes at the source, pulling them away from the welder and into a hood and duct system. By creating suction right where the fumes are generated, it removes the highest concentrations before they can reach the breathing zone, giving the most effective protection against inhaling hazardous welding fumes. This targeted capture is stronger than simply diluting room air, which spreads contaminants through the space and can still expose the welder. LEV doesn’t purposefully change humidity or oxygen levels—its purpose is to remove contaminants. For best results, keep the hood close to the weld and ensure the system has adequate capture velocity and clean, maintained filters.