The highest trace concentration of nitrous oxide allowed in the OR atmosphere by NIOSH is which?

The highest trace concentration of nitrous oxide allowed in the OR atmosphere by NIOSH is which?

• A. 1 ppm
• B. 5 ppm
• C. 25 ppm
• D. 50 ppm

Answer: (C)

Occupational exposure limits for inhaled anesthetics are meant to protect staff from long-term health effects. For nitrous oxide, NIOSH sets a recommended exposure limit of 25 parts per million as an 8-hour time-weighted average. This means the average concentration over a typical workday should not exceed 25 ppm. The other numbers are either far lower than what NIOSH allows on an daily average or exceed the NIOSH recommendation for a prolonged period, so they don’t reflect the standard NIOSH limit. In practice, staying within this limit relies on good room ventilation, effective scavenging systems, and minimizing ambient nitrous oxide exposure during anesthesia.

Occupational exposure limits for inhaled anesthetics are meant to protect staff from long-term health effects. For nitrous oxide, NIOSH sets a recommended exposure limit of 25 parts per million as an 8-hour time-weighted average. This means the average concentration over a typical workday should not exceed 25 ppm. The other numbers are either far lower than what NIOSH allows on an daily average or exceed the NIOSH recommendation for a prolonged period, so they don’t reflect the standard NIOSH limit. In practice, staying within this limit relies on good room ventilation, effective scavenging systems, and minimizing ambient nitrous oxide exposure during anesthesia.