Tyre Microplastics: The Emissions Nobody Talks About

When people picture vehicle emissions, they think of the exhaust pipe. But a growing body of research points to a quieter, invisible source: the tyres themselves. As rubber meets the road, microscopic fragments break away and scatter into the environment. These are often called “non-exhaust emissions”, and in Australia they are only now starting to be measured. This guide explains what tyre microplastics are, how serious the problem looks here, and the small changes that genuinely reduce your footprint.

What are tyre microplastics?

Tyre microplastics are usually described by researchers as tyre and road wear particles, or TRWP. A tyre is not pure rubber — it is a complex blend of natural and synthetic rubber, fillers, oils and chemical additives. As the tread abrades against the road surface, it releases a mixture of this rubber compound bound together with fine bits of road material (bitumen, grit and brake dust). The particles range from visible crumbs down to microscopic and even nanoscale fragments light enough to drift on the wind.

Because synthetic rubber is a type of plastic polymer, these particles are counted as microplastics. The faster the wear, the more particles released — which is why the same driving habits that chew through your tread quickly also generate the most pollution. If you want to understand what drives tread loss in the first place, our guide to how driving style changes tyre life covers the mechanics.

How big is the problem in Australia?

Globally, researchers estimate that about 6 million tonnes of tyre wear particles are released each year, and tyre wear is now recognised as one of the world’s largest sources of microplastic pollution. Australia’s heavy reliance on cars, utes and long road-transport distances means we contribute our share.

Local evidence is finally arriving. A University of Queensland study (published 2026) sampled dust from 30 Brisbane balconies between 2024 and 2025 and found tyre additive chemicals on 29 of the 30 balconies. It was described as the first quantitative evidence of tyre pollutants settling on Australian homes. Balconies closer to the city centre and closer to ground level carried higher concentrations, and wind speed strongly influenced how much tyre material was deposited. Researchers are candid that, as a nation, “we still know very little about how widespread this pollution is in Australia” — so treat emerging figures as early indicators rather than settled numbers.

What is 6PPD-quinone and why does it matter?

One chemical dominates the conversation. 6PPD is an additive put into tyres to stop the rubber degrading and cracking — a genuinely useful anti-ageing agent (the same ageing process we describe in our article on UV damage and dry rot). The problem is what it becomes. When 6PPD reacts with ozone in the air, it forms a by-product called 6PPD-quinone.

6PPD-quinone has been linked overseas to mass die-offs of salmon in the United States, where rain washed road runoff into spawning streams. In the Brisbane balcony study it was detected on 23 of the 30 balconies, alongside other tyre-related chemicals such as HMMM. Researchers suggest outdoor residential dust may be an important “sink” for it, with implications for human exposure that are still being investigated. No safe or unsafe exposure level has been established for people, so the honest position is: it is widespread, it is under study, and conclusions are not yet in.

Where do tyre particles end up?

Tyre wear does not simply vanish. Particles follow three broad paths:

• Air: the finest fragments become airborne and settle on surfaces — including, as the Brisbane work showed, balconies and homes near busy roads.
• Soil and roadside: heavier particles drop near the kerb and build up in verges and gutters.
• Water: stormwater carries roadside particles into creeks, rivers and ultimately the ocean. This is the pathway most associated with the overseas fish die-offs.

This is also where tyre pollution connects to end-of-life tyre management. Whole tyres that are dumped or stockpiled add a separate waste burden on top of the particles shed during use — see our guide to where to dispose of old tyres, state by state and how tyres are recycled in Australia.

Do electric vehicles make tyre pollution worse?

It is a fair question, because EVs remove the exhaust pipe entirely. The trade-off is weight. A battery pack is heavy, and heavier vehicles — combined with instant electric torque — tend to wear tyres faster, which means more particles shed per kilometre. Researchers note that while EVs cut tailpipe emissions, their extra mass could raise tyre and road wear. We cover the mechanism and the fixes in why EV tyres wear out faster. The takeaway is not “don’t buy an EV” — it is that non-exhaust emissions deserve attention regardless of what powers the car.

How can you reduce your tyre emissions?

You cannot eliminate tyre wear, but the same habits that make tyres last longer also cut what you shed. The biggest levers are driving style, pressure and mass.

Correct inflation is the easiest win, and it has a bonus: it also saves fuel. Our guide to tyre pressure and fuel economy shows how much you lose when pressures drop. For buyers who want to weigh environmental claims when choosing rubber, see whether eco tyres are actually better for the environment.

Bottom line: Tyre microplastics are a real, measurable form of pollution — not science fiction — and Australia is only beginning to map them. You can’t drive with zero wear, but smoother inputs, correct pressures and avoiding dead weight cut what your tyres shed while making them last longer. The cleanest kilometre is the one driven gently on a properly inflated tyre.

Frequently asked questions

Are tyre microplastics worse than exhaust emissions?

For some pollutant types, non-exhaust emissions (tyres and brakes) now rival or exceed tailpipe particulates in many studies, because exhaust emissions have been heavily regulated while tyre wear has not. They measure different things, so they are not directly interchangeable, but tyre wear is no longer a minor footnote.

Does tyre brand or type change how much I shed?

Yes. Faster-wearing compounds release more material, so a tyre with a higher wear rating will generally shed less over its life. Tread pattern and driving conditions matter too. Aggressive off-road tyres on sealed roads wear and shed faster than a touring tyre.

Can I filter or capture tyre particles?

Not at the individual level yet. Capture devices fitted near the wheel exist as prototypes but are not available to ordinary drivers in Australia. For now, reducing how much you shed — through driving style and pressure — is the practical option.

Is 6PPD-quinone dangerous to humans?

It is linked to serious harm in some fish species and has been detected in human urine and household dust, but researchers have not established safe or unsafe exposure levels for people. It is an active area of study rather than a settled health verdict.

External references: University of Queensland — microplastic tyre pollution in Brisbane balcony dust; UQ QAEHS — tracking tyre-related microplastic pollution in the Australian environment.