We report an effective method of scavenging nitric oxide and nitrogen
dioxide. We have compared three agents, a commercially available filte
r, soda lime and activated charcoal, for their effectiveness and durat
ion of action. Complete absorption of nitric oxide and nitrogen dioxid
e for a period of 170 h was obtained using the commercial filter. Howe
ver, soda lime and charcoal were unable to successfully scavenge eithe
r gas. The resistance characteristics of this filter when dry or humid
ified were determined.