THE PHOENIX THE PHOEN
EDITOR’ S NOTE
The coming brake emissions challenge
Engine emissions might not be the only particle pollution tax vehicles will pay, in the near future.
Drum brakes are very rare on modern passenger vehicles. They’ re usually only found on budget vehicles at the rear, where cost is a consideration and weight ratings are low. is potentially a health issue, with tiny brake dust particles potentially being very toxic.
The main concern is the release of fine copper and iron particles. For operators in the automotive braking system industry, the warnings are clear. When compliance engineers hear Euro 7 standards, they usually think diesel aftertreatment systems and catalytic converters. Not brakes.
For commercial truck operators, drum brakes are still widely used. In the South African bakkie market, where buyers are both commercial fleets and private passenger car users, there is a mix of disc and drum brakes. The trend is towards all-disc brake set-ups, with even Toyota’ s Hilux, which defines the local bakkie market, now offering disc brakes at the rear, on its more expensive models.
As passenger cars have become heavier and more powerful, the need for equally powerful brake systems has developed. Modern ADAS systems mean near-constant brake interventions, too, further increasing inadvertent brake wear when drivers aren’ t commanding the brake pedal with their left foot.
Compared to the enclosed design of a drum brake, the open design of a disc brake system provides superior stopping power, cooling, and modulation for ADAS systems. Disc brakes also allow easier wheel corner packaging with sophisticated suspension systems.
But the latest Euro 7 vehicle emissions standards include a provision for brake dust emissions. The limits for petrol- and diesel-powered vehicles are 7 mg / km, while battery electric vehicles( BEVs) have a stricter baseline of 3 mg / km.
Evolving non-exhaust vehicle emissions might see a return to drum brakes for passenger vehicles, with advanced ceramic pads, to future-proof brake systems for increased emissions regulations.
Some engineers believe the regenerative benefits of BEVs could be a solution, but that leaves the question of pure petrol and diesel models in the future. Vehicles where high-load regenerative braking is not an option.
Lance
For all the formidable technical benefits of disc brakes, there is a looming issue. Particle emissions from brake wear could become a future tax risk for vehicle owners with disc brakes. It’ s similar to how the inner-city emission charge or ban on diesel vehicles was unimaginable in the 1990s. In 2026, that is becoming a reality in some of the world’ s healthiest European and Asian cities.
What is the issue? Disc brakes, with their open design, expel brake pad material outwards into the road environment. That natural mechanical wear between disc and pad material
JULY | AUGUST 2026 1 WORDS IN ACTION