Pollutant Information: Non Methane VOC
About Non Methane VOC
Category: Air pollutants
Non-methane volatile organic compounds (NMVOCs) are organic compounds, which differ widely in their chemical composition. These organic compounds are often grouped under the NMVOC label as the majority display similar behaviour in the atmosphere. NMVOCs are emitted to air as combustion products, as vapour arising from petrol and solvent use and from numerous other sources. NMVOCs are involved in the photochemical production of ozone and secondary organic aerosols in the atmosphere over a large spatial scale. Different individual NMVOCs have a different reactivity in the atmosphere and therefore a different propensity to forming ozone and organic aerosols. Some NMVOCs also have a direct impact on human health. For example, benzene and 1,3-butadiene are both carcinogens.
The diversity of processes which emit NMVOCs is huge, covering not only many branches of industry, but also transport, agriculture and domestic sources. The largest categories of NMVOC emissions in 2021 were industrial processes and product use (58% of the UK total), followed by agriculture (13%) and extraction and distribution of fossil fuels (17%). In comparison, only 6% of the NMVOC emissions in 2021 arose from transport and other mobile sources, and 5% from stationary combustion plants. Among the combustion-related sources, the most significant were the use of wood as a residential sector fuel, contributing 2% of UK emissions of NMVOC in 2021. Natural emissions of NMVOCs from vegetation are also reported, but are not included in the UK emission total, in accordance with UNECE guidelines.
UK emissions of NMVOC have decreased by 72% between 1990 and 2021, and this reduction is largely due to controls on emissions from road vehicles, which have delivered a 97% reduction in road transport sector emissions since 1990. There have also been large reductions in emissions from industrial processes and product use (51% reduction) and from extraction and distribution of fossil fuels (84% reduction), these being mostly due to emission controls and reductions in UK production of fossil fuels such as North Sea oil and coal.
The NMVOC emission time series shows an increase in emissions between 1970 and 1990 with minor peaks in 1973 and 1979, followed by a steady reduction in emissions during the 1990s and 2000s. The latter is largely a reflection of the increasingly stringent emission limits across a range of sectors.
The UK is currently on track to meet the National Ceiling Emissions Directive and Gothenburg Protocol targets for NMVOCs in 2030, but emissions will need to be reduced by a further 12% from 2021 to meet this target.
Time series graph
|Start year||End year||Sector||Information||Impact|
|1993||1993||Agriculture||Field burning of agricultural waste stopped after 1993.||Decrease in emissions|
|1999||2011||Production Processes||Tightening emission controls for the chemical industry under IPPC enforced by the Environment Agency and Defra.||Decrease in emissions|
|1999||2001||Solvent & Other product use||Introduction of the Solvents directive||Decrease in emissions|
|2004||2006||Solvent & Other product use||Reduction in solvent content of paints and other products (Solvents and Deco Paints Directives)||Decrease in emissions|
|1990||1999||Transport||Introduction of petrol cars with early 3-way catalysts.||Decrease in emissions|
|1992||2018||Transport||Stricter Euro I - VI emission regulations come in on trucks and buses offsets increasing vehicle km. Â Impact takes time to have an impact as only new vehicles need to meet standards.||Decrease in emissions|
|1990||2010||Transport||Switching from petrol to diesel cars||Decrease in emissions|
|2021||2021||Road transport and aviation||As a result of easing COVID-19 restrictions, NMVOC emissions from road transport and aviation in 2021 were 4.8% and 26% higher than they had been in 2020 respectively||Increase in emissions|