What are the environmental impacts of medical nitrous oxide?

Nitrous oxide is a Greenhouse Gas with a Global Warming Potential (GWP) of 265 according to GHG Protocol AR5. BOC have a continuing focus on the environmental emissions from our Nitrous oxide and Entonox operations and we strive to reduce these wherever possible. BOC continue to assess our nitrous oxide and ENTONOX filling processes to identify opportunities for improved practices and efficiencies that further reduce our carbon footprint.

Of the small 5% contribution that nitrous oxide makes to the total greenhouse effect, most of this is due to agriculture. Clinical sources of nitrous oxide form only 1% of this contribution. Thus, the clinical use of nitrous oxide only contributes 0.05% towards the total greenhouse effect.

Nitrous oxide is an extremely safe medicinal gas when used appropriately and with the correct scavenging equipment and air exchange rates. The current UK exposure levels of a 100ppm (based on an 8hour time weighted average) are easily achieved when these systems are adopted.

Therefore nitrous oxide should be administered in rooms with suitable ventilation and/or scavenging equipment. It should be administered at the lowest effective flow to avoid waste and ecological consequences.

It has been demonstrated that, “as long as routines for gas scavenging, in line with occupational limits, are followed, there is insufficient evidence to recommend any routine medical surveillance of personnel exposed to trace concentrations of waste anaesthetic gases” (1)