How many air changes per hour should welding shops have as a minimum?

Welding shops should maintain a minimum of four air changes per hour to ensure proper ventilation and maintain a safe working environment. This level of air exchange is crucial for diluting and removing harmful fumes, gases, and particulates that can arise during welding processes. Adequate ventilation reduces the concentration of toxic substances in the air, helping to mitigate health risks for workers. The recommended standard underscores the importance of air quality in industrial settings where welding activities take place, thus promoting both safety and compliance with occupational health regulations. The choice of four air changes per hour is a balanced approach to effectively manage air quality without exacerbating energy costs or over-ventilating the space.