Arc welding operations expose workers to intense heat, ultraviolet radiation, and electrical hazards. Welding equipment must be properly installed, grounded, and maintained in safe operating condition. Welding cables must have proper insulation and must not have damaged or spliced areas. Cable connections must be clean and secure. Electrode holders must not be left connected to the electrode with the cable draped over the worker's shoulder. The work clamp must be properly attached to the workpiece and not grounding through personnel or structures. Wet conditions require special precautions including rubber mats, dry clothing, and increased frequency of equipment inspection. Confined spaces require ventilation to prevent accumulation of welding fumes and shielding gases. Proper ventilation of welding areas must prevent excessive exposure to welding fumes. Personal protective equipment including welding helmet with proper shade, leather apron, and leather sleeves must protect against burns. Closed-toe shoes must be worn; pant legs must not have cuffs that can catch sparks. Long-sleeved shirts made of fire-resistant material must cover arms. Hearing protection must be worn in high-noise environments. Chipping and grinding of welds must be done with proper eye protection and guards installed on grinders. Fire extinguishers must be available at all welding locations. Work must stop during high winds or extreme weather. Proper ventilation must remove welding fumes and shielding gases.