Proposal to establish a new supplement to UN Regulation No. 179, improving and correcting brake emissions measurement procedures for light-duty vehicles of categories M₁ and N₁. The regulation applies full-friction braking testing on brake dynamometers using the WLTP-Brake cycle comprising ten trips and 303 brake deceleration events. Testing includes three sections: cooling air adjustment, brake bedding with five cycle repetitions, and emissions measurement with three cycle repetitions. Compliance is demonstrated by measuring PM10 and SPN10 emissions from brake corner emission family parents, with whole-vehicle emissions calculated using friction braking share coefficients specific to vehicle electrification types. PM10 limits are 3 mg/km for M₁/N₁ vehicles and 5 mg/km for N₁ Class III/N₂ vehicles. Conformity of production requires annual testing of brake corner emission families with statistical evaluation per decision charts through 31 December 2029 (Phase I, PM10 only), with Phase II from 1 January 2030 evaluating both PM10 and SPN10. A version of this document with tracked changes is available.

Proposal to include testing of vehicles with limited speed. The document sets out the laboratory measurement procedure for brake emissions from light-duty vehicles of categories M₁ and N₁, including vehicles with maximum speed below the Base cycle maximum speed. Testing involves three sections: cooling air adjustment, brake bedding with five repetitions of the WLTP-Brake cycle, and brake emissions measurement with one WLTP-Brake cycle. Brake corner emission families are tested on a component test bench under full-friction braking conditions, measuring PM₁₀ and SPN₁₀ emissions. Compliance is demonstrated using brake corner emissions family parents. Conformity of production requires monthly sampling and testing of brake components, with results evaluated using statistical decision charts through 31 December 2029 for PM₁₀ and thereafter for both PM₁₀ and SPN₁₀.

Proposal to establish a new UN Regulation transposing UN GTR No. 24 into uniform provisions concerning approval of non-original and identical replacement brake parts (brake pads, drum brake linings, brake discs, and brake drums) with regards to particle emissions. The regulation applies to vehicles of category M₁, N₁, and N₂ between 3.5 and 5 tonnes maximum mass. Replacement brake parts must comply with particle emission limits, with emission factors calculated using test wheel load and friction braking share coefficient for the brake emissions family parent. Approval marks must be affixed to approved parts, and conformity of production shall be verified through sampling and testing procedures.