Workers in Arizona whose jobs expose them dangerous airborne contaminants must be protected. Employers must establish engineering controls such as scrubbing to remove contaminants and providing adequate ventilation to limit exposure, but if such controls are not sufficient, respirators must be provided to prevent work injury. The Occupational Safety and Health Administration has a respiratory protection standard that mandates medical evaluation of employees before they wear respirators.
Respirators are designed in two types. The first type is used to prevent inhalation of hazardous materials. They could be either particulate respirators to prevent particulate matter from entering the workers' lungs or gas masks that filter out gases and chemicals. The second respirator type provides the worker with respirable air that could be compressed clean air supplied from a remote source such as those used by airlines. Alternatively, respirators could have built-in air supplies, known as self-contained breathing apparatus.