Nitrous oxide in UK dentistry adds substantial greenhouse emissions, national audit shows
Feb 28th 2026
A UK quality improvement project mapped nitrous oxide use at 128 dental sites and found a sizable carbon footprint per sedation episode, big variation in supply and practice, and practical steps to cut emissions while keeping patient benefits.
- National quality improvement project collected 891 inhalation sedation episodes from 128 UK dental sites across 31 organisations.
- Average carbon footprint was 28.62 kg CO2e per sedation episode and 518.25 kg CO2e per typical service week.
- The study used a global warming potential of 265 for N2O but a later update to 273 means the footprint is likely slightly underestimated.
- Most sites used cylinder supplies (84%) while 16% used piped manifold systems.
- Estimated wastage averaged 9% overall, 4% at cylinder sites and 30% at piped sites, with large variation between services.
- Average clinical settings were 5.84 litres per minute flow rate, 34.5% N2O titration, and 28 minutes duration, with flow rate driving most of the emissions.
- Eight in ten sedation episodes were for paediatric patients and the national success rate for procedures under inhalation sedation was 92%.
- About 40% of patients might have been eligible for standard IV sedation but IV availability and age criteria were limited across services.
- Authors recommend monitoring and reducing wastage, standardising training to lower unnecessary flow rates, avoiding routine acclimatisation visits under sedation, improving equipment metering, and researching safer alternatives and capture technologies.