New research warns of unregulated NEE threat

New research has found that pollution from tyre wear can be 1,000 times worse than what comes out of a car’s exhaust.

According to Emissions Analytics, harmful particle matter from tyres and brakes – or non-exhaust emissions (NEE) – is a very serious and growing environmental problem, one that is being exacerbated by the increasing popularity of large, heavy vehicles such as SUVs, and growing demand for electric vehicles, which are heavier than standard cars because of their batteries.

NEE are particles released into the air from brake wear, tyre wear, road surface wear and re-suspension of road dust during on-road vehicle usage. No legislation is in place to limit or reduce NEE, but they cause a great deal of concern for air quality.

To understand the scale of the problem, Emissions Analytics performed some initial tyre wear testing. Using a popular family hatchback running on brand new, correctly inflated tyres, it found that the car emitted 5.8 grams per kilometre of particles.

Compared with regulated exhaust emission limits of 4.5 milligrammes per kilometre, the completely unregulated tyre wear emission is higher by a factor of over 1,000. Emissions Analytics warned that this could be even higher if the vehicle had tyres which were under-inflated, or the road surfaces used for the test were rougher, or the tyres used were from a budget range – all very recognisable scenarios in ‘real world’ motoring.

Richard Lofthouse, senior researcher, said: “It’s time to consider not just what comes out of a car’s exhaust pipe but particle pollution from tyre and brake wear. Our initial tests reveal that there can be a shocking amount of particle pollution from tyres – 1,000 times worse than emissions from a car’s exhaust.

“What is even more frightening is that while exhaust emissions have been tightly regulated for many years, tyre wear is totally unregulated – and with the increasing growth in sales of heavier SUVs and battery-powered electric cars, non-exhaust emissions (NEE) are a very serious problem.”

Nick Molden, CEO of Emissions Analytics, said: “The challenge to the industry and regulators is an almost complete black hole of consumer information, undone by frankly out of date regulations still preoccupied with exhaust emissions. In the short term, fitting higher quality tyres is one way to reduce these NEEs and to always have tyres inflated to the correct level.

“Ultimately, though, the car industry may have to find ways to reduce vehicle weight too. What is without doubt on the horizon is much-needed regulation to combat this problem. Whether that leads to specific types of low emission, harder wearing tyres is not for us to say – but change has to come.”