Anaesthetic N2O remains in the atmosphere up to 120 years as a potent greenhouse gas and dominant ozone depleting substance. It’s complete mitigation will be essential to meet our climate change duties and within the NHS Scotland Climate Emergency and Sustainability Strategy we aim to achieve net zero emissions of this agent by 2027. It is estimated across all health boards that most of our anaesthetic N2O emissions is due to system loss up to a magnitude of 83-100 percent. This is both costly and polluting. This is a technical document to facilitate the discontinuation or a leaner physical provision of anaesthetic nitrous oxide within NHSS acute sites. This document should be read in conjunction with the latest version of the nitrous oxide mitigation implementation plan.