Emissions of air pollutants in the UK – particulate matter and wood burning stoves

What is the latest news on wood burning stoves and particulate emissions?

It was only a couple of weeks ago that I updated on the government’s latest review of the Environmental Improvement Plan 2023 and the main fact that there are no plans to ban wood burning stoves, but it wants to continue to improve regulations for burning at home by:

• Tightening the limits that new stoves in Smoke Control Areas (SCA) must meet, reducing the limit from 5g of smoke per hour to a maximum of 3g.
• Extending solid fuel legislation to fuels burnt outside .
• Implementation of measures to drive a shift away from older, more polluting appliances to newer appliances.

What is the Air Quality Neutral plan for London all about?

Since this announcement, the London Mayor’s office, on 8^th February launched the Air Quality Neutral London Plan Guidance. Basically this outlines requirements for Transport Emission Benchmarks (TEB) and Building Emissions Benchmarks (BEB) that all new residential and commercial planning applications within the capital must meet in order to be classed as Air Quality Neutral (AQN). The key point to note is that the BEB emission rate for particulate matter is ZERO and that “Any development that uses solid or liquid fuels for primary or secondary heating will not be Air Quality Neutral”. There is no indication within the guidance of this having any effect on existing stove installations on existing dwellings, but it will rule out the specification of a solid fuel appliance in any new build development in London.

Is the latest report from Defra - 'Emissions of air pollutants in the UK - particulate matter' data a concern?

It was only last week on 14^th February that Defra released its latest update (2021 data) to the Emission of air pollutants in the UK – Particulate matter data.

There was a slight concern in the industry that these figures being released would show an increase in particulate emissions from domestic burning due to the increase in people turning to wood burning to save money on their energy costs, however it is important to note that these figures are up until 2021 and NOT last year. With an over 60% increase in wood burning stove sales in the last 12 months, it is the 2022 emissions data that will be an interesting read – let’s hope the pendulum will start to swing the right way!

What does the data really mean for domestic wood burning?

As with all statistics, it is important to read all the facts and dig a little deeper rather than taking the media and journalist’s viewpoint which can easily heavily distort the true picture.

a) Levels of particulate matter 2.5 (PM2.5) emissions have increased across ALL reported sectors for 2021 compared with 2020 – not just domestic combustion.

UK annual emissions of PM2.5 by 2021 major emission source: 1990, 2005, 2020 and 2021

b) The increase in wood fuel emissions as part of the overall domestic combustion emissions total is down to the decline in the use of coal which has was banned in 2021. The wood fuel figure as a % of domestic combustion PM2.5 emissions has been steadily increasing year on year since 1990 for the same reason – a switch from coal to wood. Fossil fuel to a sustainable renewable fuel!

c) The latest figures for PM2.5 from domestic combustion, as always, include ALL appliance types – open fires, old stoves and modern Ecodesign models. Using independent research carried out last year for the SIA by Mitchell and Cottam the report calculates that the breakdown of emissions between appliances can be shown as follows:

It is important to note that open fires and older stoves combined account for just over 95% of all PM 2.5 emissions attributed to domestic combustion. 

d) The overall total UK PM 2.5 emissions from all sources has DECREASED by over 40% in the last 20 years and is a third of what it was in 1990.

Trends in total annual emissions of PM10 and PM2.5 in the UK, 1970 to 2021

What do the Stove Industry Association say about the latest data?

Commenting on the latest emissions data, Andy Hill, chair of the Stove Industry Association (SIA) said:

“The UK stove industry continues to innovate, producing modern wood burning stove appliances that are more efficient and less polluting than ever before. While the total figures attributable to domestic combustion within the government’s latest figures have caused many critics to attack all forms of domestic wood burning once again, the overall PM2.5 emissions linked to the very latest wood burning stove models is just 1.3% of the UK total.

A modern stove that is Ecodesign compliant, such as a clearSkies certified appliance, will produce up to 90% less emissions than an open fire and up to 80% less* than many older stoves. What other sector can claim to have achieved technical advances leading to such a significant reduction?

Members of the SIA have seen unprecedented demand over the last 12 months for appliances that meet the latest Ecodesign requirements, and we would urge anyone using an open fire or older stove model to consider upgrading their appliance to a clearSkies certified model*.

In addition, consumers must ensure that they burn responsibly by only using good quality, dry wood fuel such as Ready to Burn certified logs, having their chimney regularly swept and their stove well maintained, and ensuring that the installation is carried out by a qualified professional such as a HETAS or OFTEC registered installer.”

^* Verified by independent emissions testing.

ClearSkies certified appliances have been independently verified as meeting the requirements of the Ecodesign regulation, plus any clearSkies appliance certified at Level 3 and above has been checked as having been granted Defra exemption, meaning it can be used to burn wood in a Smoke Control Area.

What are our thoughts on the latest media coverage on wood burning and particulate emissions?

Having had a far more positive run in the media over the last 12 months citing wood burning stoves as a good thing to have to reduce heating costs and with a more sustainable and renewable fuel, there are now some bumpy waters and ammunition for the anti-wood burning fraternity to get their teeth into.

Having been very involved with the Stove Industry Association over the years, I believe great progress is being made and when I look at the most revealing table above showing that only 4.8% of emissions from domestic combustion are attributable to modern Ecodesign stoves, I hold real hope and confidence that the industry is acting responsibly to reduce emissions.

The realistic direction now is to continue improving stove efficiencies, but most importantly to move away from open fires and very old appliances and replace with incredibly efficient Ecodesign stoves which I did two years ago – you will be amazed. As members of the great wood burning community, don’t we all want to see the figures for domestic combustion reduced?

Nic Snell

19^th Feb 23