By: 28 July 2022
UK first as ‘green gas and air’ to be used for first time at St George’s Hospital

Women in labour and dental patients will be given ‘green gas and air’ at St George’s hospital, reducing pain on the planet as well as during childbirth and tooth extractions.

In a UK first, St George’s University Hospital is investing in a device in its dental unit dubbed the ‘catalytic converter of gas and air’. 

Nitrous oxide, regularly combined with oxygen, to produce Entonox, provides sedation in dental and emergency procedures as well as pain relief in labour. The gas has almost 300 times the global warming potential of carbon dioxide. 

The mobile nitrous oxide conversion unit at St George’s will be the first in the UK to be trialed in a dental department and breaks gas down into harmless oxygen and nitrogen before it is released, thereby reducing its impact on the environment as well as staff exposure to the medical gas.

It is already being used in St George’s endoscopy and the midwifery led birth unit.

St George’s University Hospitals NHS Foundation Trust is the largest healthcare provider and major teaching hospital for south west London, Surrey and beyond – and one of the largest healthcare providers in the UK – serving a population of 3.5 million.

Dr Emma Evans, South West London Clinical Lead for Net Zero and Consultant Anaesthetist at St George’s, said: “Patients won’t experience any difference in their clinical care and how they receive pain relief remains the same, but after its use, it will be disposed of through the device to breakdown the gas to be more environmentally friendly.

“After trialing mobile devices in the dental, endoscopy and midwifery led birth units, we will scope out the potential for a central system to service a larger number of clinical areas too, to further reduce our overall carbon footprint.”

This is the second time St George’s has been recognised for its sustainability strategy after the Trust was the first in the UK to decarbonise its patient menu last year.

Kate Slemeck, Managing Director for St George’s University Hospitals NHS Foundation Trust, said: “These devices eliminate 99% of the nitrous oxide that is released into the environment and their implementation plays a small but very important part in our overall green plan, paving the way for us to reduce our emissions.

“We all have a role to play in tackling climate change and St George’s is committed to playing its part in making the NHS the world’s first net zero health service.”

With more sustainable investments and interventions like these, we will reduce the rise in patients coming in with conditions exacerbated by air pollution such as asthma, cardiovascular disease (CVD), and lung cancer.

The introduction of these devices, which are made by Medclair, working in partnership with Ultraflow manufacturer BPR Medical, is the latest effort by St George’s to reduce its carbon footprint.

Managing Director of BPR Medical, Richard Radford, said: “We are delighted to be working to provide a sustainable and environmentally-friendly pain relief solution for patients at St George’s. The device handles exhaled nitrous oxide in a way that is both climate-friendly and convenient to the patient, while giving them safe and efficient pain relief.”

Chief Executive of Medclair, Jonas Lundh, said: “It’s fantastic to see that more hospitals across the NHS are adopting nitrous oxide conversion systems. Scaled across the entire health service, this technology could reduce NHS nitrous oxide emissions by up to 75%.

“We are seeing more and more innovative efforts like this across the health service to tackle the global climate crisis.”

Other sustainability initiatives at St George’s include:

  • Using recycled surgical instruments and items in operating theatres. For instance, in hand surgery, an estimated 22,000 items per year have been saved from the surgical kits used in operations
  • A combined heat and power plant on the St George’s site provides excess renewable energy back to the National Grid – 1.9million kWh was exported back in 2019-20, enough to boil a kettle over 46 million times
  • St George’s became the first Trust in the country to introduce a carbon-neutral patient menu, sourced from ingredients with a low carbon footprint. Around 23 tonnes of carbon is saved, the equivalent of planting 30 acres of forests.


Image: Vicky Grayson Lead Midwife for St George’s midwifery led birth unit