Ventilation Work activity or the presence of harmful substances in industrial environments frequently produces airborne contaminants. These contaminants can be controlled by isolating them from the breathing zone, substitution of a less hazardous substance or process, or by providing adequate ventilation. Ventilation is one of the most common engineering control methods and can be defined as the movement of fresh air into a space in order to replace contaminated air and/or control the temperature in a space. Natural ventilation usually does not provide a sufficient volume of airflow to ventilate enclosed spaces or to promptly remove highly toxic airborne contaminants from breathing...