Two new exhaust control methods for scavenging and removing excess ribavirin aerosol were evaluated. Air samples were collected from pediatric intensive care rooms to determine the concentration of ribavirin. 2. Both control methods produced a 99.9% reduction between patient breathing zone concentrations and general room air concentrations. The average room air concentrations of ribavirin were 64 and 37 micrograms/m3 with the control methods in place, compared to average patient breathing zone concentrations of 45,000 and 58,000 micrograms/m3. 3. Additional control methods are reviewed, and published ribavirin environmental monitoring data is summarized. 4. Though the effect on fetal development in humans is not known, it is recommended that occupational exposure to ribavirin aerosol be minimized. A safe level for occupational exposure was calculated to be 91 micrograms/m3 for an 8-hour time weighted average.