The most harmful route of entry for hazardous chemicals is through inhalation and one of the most effective means to control is exposure is through ventilation. Well designed ventilation can remove the contaminant before it is breathed in by the employee. As a result, the hazard is eliminated or greatly reduced and the need for respiratory protection also eliminated or lessened.
Local exhaust ventilation (LEV) is the preferred method to reduce chemicals in the air in most cases. It captures the contaminant at the source and removes it from the workplace. LEV uses a hood that can be placed near the contaminant. The hood is connected to a duct, fan, and stack. Air cleaners may be placed at various stages along the system. Examples include portable fume extractors, downdraft tables, ventilated tools, paint booths, and fixed systems