Changes to the way decorative paints and varnishes are made have significantly reduced harmful air pollution emissions over the past two decades, according to new research involving scientists from the National Centre for Atmospheric Science (NCAS).

The findings show that regulation of paint-derived volatile organic compounds (VOCs) works. But, they also underline the need for air quality policy and industry standards to be updated to reflect new chemical compositions in paint.

Most VOCs are safe to breathe in low concentrations, although they can have serious implications for our health if concentrations build up in poorly ventilated spaces – which in part explains why we are advised to open windows when painting indoors, and why the 1999 Solvents Directive and 2004 Paints Directive were established. When those same VOC fumes pass outside they go on to form harmful photochemical smog.

Since then, there has been a major decline in VOCs emitted from paints in the UK. This is linked to the transition away from hydrocarbon solvents, to a wider range of different chemicals.

“Rules on product labelling followed the 1999 and 2004 Directives, and now every paint pot has a VOC pollution symbol on it. The Directives have worked: the amount of VOCs emitted from paints and varnishes has fallen substantially in the UK, from a peak in the early 2000s of around 500g per person per year, to around 200g per person today,” shares Professor Lewis.

Understanding chemical emissions from consumer products, like paints, is a vital step in managing indoor air quality and people’s exposure to pollutants. But it also affects outdoor air quality when chemical fumes are released by windows or extractor fans.

By analysing emissions from modern UK paints and comparing them with historical data, the researchers found that paint‑related VOC emissions per person have fallen by around 60% since the mid‑2000s – closely tracking regulatory limits introduced to reduce their use.

“We set out to understand how paint chemistry has changed over time and whether environmental regulation has really made a difference. What makes this research stand out is how wide‑ranging our approach was. Instead of relying on a single method, we compared national statistics from before and after the EU Paints Directive, lab experiments to identify the chemical release from drying paints, and computer models to build a complete picture of paint emissions across more than 30 years,” says Lidia Alfanti, a doctoral scientist at the University of York and lead researcher of the study.

Lidia adds: “Bringing together real‑world data, lab chemistry and modelling allowed us to see not just that emissions have fallen, but how the chemistry of paint pollution has fundamentally changed.”

Crucially, the study shows that the type of chemicals released by paints has changed as well as the quantity. Older paints tended to emit hydrocarbons that readily form secondary air pollutants. Modern paints now emit different compounds, such as alcohols and esters, which are less reactive in the atmosphere and produce fewer harmful by‑products.

“This is a clear example of regulation delivering measurable environmental benefits. But it also shows that we need to regularly update how we assess and regulate emissions as products and technologies evolve,” highlights Dr Sarah Moller, a senior researcher and knowledge exchange fellow at NCAS and the University of York.

Air pollution assessments, air quality prediction models, and nationwide emissions inventories are still using VOC composition data from the 1990s – which no longer reflect the paints being made and used today.

“Continuing to use assumptions about VOC composition, which are based on pre-regulation data and old paints, could mean pollution risks are misjudged or that emerging issues are overlooked,” shares Dr Amber Yeoman, a research associate in atmospheric emissions at NCAS and the University of York.

The team’s work provides new data that can help policymakers improve national and local air quality inventories, design more targeted VOC regulations, and to better assess indoor air quality – which is increasingly recognised as a public health priority.

The findings are also significant for manufacturers and the construction sector. While modern decorative paints are cleaner than previous generations, they still remain a major source of VOC emissions, particularly in poorly ventilated spaces.

The research highlights opportunities for industry to further reduce emissions through product design, contribute to healthier buildings, and to support evidence-based standards for paints and indoor environments.

“This study shows that air pollution control is not a one‑off achievement. It’s an ongoing process that depends on independent science, up‑to‑date data, and close collaboration between researchers, policymakers, and industry,” says Lidia Alfanti.

The team of researchers are continuing to work with the UK’s Department for Environment, Food and Rural Affairs to improve emissions data and ensure air quality policies reflect the realities of modern products and environments.