Devices used to reduce levels of airborne gaseous compounds by passing the air through materials to extract the gases. The performance of solid sorbents is dependent on the airflow rate, concentration of the pollutants, presence of other gases or vapors, and other factors.

Individual atoms or molecules that spread evenly throughout a volume of air, and cannot be collected by ordinary particulate filters.

Part of the basal ganglia. Damage can result in flexion dystonia, impaired postural reflexes.

Specialized cell found in the human respiratory system that serves to secrete mucus.

Non-regulatory recommendations on how to achieve specific objectives.