UNECE: New methodology to measure particle emissions from tyres

 

After the adoption of a methodology for measuring emissions from braking systems last year, the UNECE’s World Forum for Harmonization of Vehicle Regulations (WP.29) has now shifted its focus to addressing emissions originating from tyres.

Comprised of a blend of natural and synthetic rubber, as well as plastic polymers and other chemical components, tyres constitute a significant contributor to non-exhaust emissions. Tyre abrasion occurs during friction with the road surface, such as during turns, acceleration, or braking. This results in the detachment of small particles (referred to as tyre weight loss), which are then released into the air and deposited on the road surface and surrounding environment. These particles pose risks to human health and can contaminate soil and water bodies through road runoff, wastewater, and airborne dispersion, potentially reaching and polluting oceans.

With the backing of the Working Party on Pollution and Energy, the Working Party on Noise and Tyres has now endorsed a proposal introducing two methods for measuring tyre abrasion under UN Regulation No. 117:

1. Conducting tests on open roads with vehicle convoys covering 8,000 kilometers.
2. Conducting laboratory tests using an abrasing rolling drum over 5,000 kilometers.

The extent of tyre weight loss due to abrasion will be quantified as milligrams per kilometer per ton of load on the tyre. These measurement techniques are set to be utilized in a market assessment initiative aimed at gathering abrasion data across various tyre sizes, patterns, and brands. This data will then inform the establishment of tyre abrasion limits to be integrated into UN Regulation No. 117 by September 2025, specifically targeting tyres fitted to passenger cars (C1 tyres).

Once these abrasion limits come into effect, tyre manufacturers will be required to ensure that all tyres sold on the market comply with the prescribed limits. Those exceeding the limits will necessitate adjustments to their material composition or manufacturing processes.

Source: https://unece.org/environment/press/unece-introduce-first-ever-methodology-measure-particle-emissions-tyres

To find out more about UNECE regulations, please contact the Institute for Global Automotive Regulatory Research directly.