How bad are HFA inhalers compared with transport CO2 emissions?

2011 the Earth and orange atmosphere taken from the International Space Station 350km above the Earths surface.  Unknown Astronaut. 

Firstly the total UK CO2e for 2018 was 379 Million tonnes, excluding international air travel (a globally agreed method to present CO2e data). I have done research into transit air travel statistics and UK airport flying kms, so I estimate the UK total CO2e is 514 Million tonnes CO2e including international air travel and freight. 

• The largest sector emitting CO2 is road transport, with transport including international flying making up (186 Mt CO2) or 36% of all the UK emissions.

• HFCs in total account for (22 Mt CO2e) or 4% of the UK annual total. 95% of these HFCs are from refrigerant and heat pump leaks, as well as industrial use.

• The HFC inhaler emissions account for just over 5% of the HFC UK total, or just 0.2% of the UK CO2e total. So very small.

I recognise that every CO2e reduction is important for the planet, but the data points very clearly at transport for requiring large scale rapid change, both road and air. Small changes in the transport sector will have the largest changes nationally and globally.

Each puff of a pMDI is typically less than 100 milligrams of HFC, multiplied by the global warming potential (GWP) of 2175 (the average for medical HFCs) gives 0.218 kg CO2e per puff or 218 gm CO2e. That would be 320 kg CO2e per year per patient for a two puff per dose twice a day medicine.

• A standard petrol or diesel car emits between 110 (Small Diesel) and 210 (SUV) grams CO2 per kilometre. A 720 km journey by yourself in an SUV from London to Edinburgh and back emits 290kg CO2 – equivalent to almost one years puffer use.

• A short haul jet emits on average 200 gm per passenger km, long haul 166 gm per passenger km. (Defra data) A 2.5 hour air journey and back is 650kg personal CO2 – equivalent to two years puffer use.

• A domestic heat pump or aircon using high GWP HFC typically leaks 7% of content per year – that is 609 kg CO2e per year – equivalent to almost two years puffer use.

A moulded monthly-use dry powder inhaler generally uses more plastic than a puffer to make, and so the HFC saving per year needs to be offset by the extra plastic. A quick sum shows that the energy and thus CO2 for the extra plastic is ~25kg CO2 per year versus 260 to 300 kg CO2e for 12 HFC puffers per year. A big % saving in CO2e per patient, but in the big picture reducing transport CO2 is so much more important for the planet.

The UK CO2e is 67 million people times 7,700 kg (7.7 tonnes) CO2e per year per person, including all the asthma puffer type inhalers making ~500 Million tonnes CO2e per year. 

The global picture (2017 data) is 7.5 billion people times 4.9 tonnes CO2e per head per year = ~37,000 Million tonnes CO2e per year (excluding international air travel).

It is my experience and opinion that the inhaler industry is slowly working on reducing the carbon footprint of future registered inhalers, and taking sustainability seriously. I do however agree with Dr Wilkinson of the NHS and NICE that speed is of the essence to get to zero carbon inhalers, but I feel that the pressure should be put on drug companies and regulatory authorities to do so. They together have the power to affect change rapidly, and provide better choices.

I do not agree with making those who have difficulty breathing, guilty about their inhaler use, which is actually prescribed for them by their doctor. It is just not justified and fair, however well-intentioned for the planet. 

What do you think? Email us: technology@upccambridge.co.uk