Standards Development

Scope

This document specifies a method for the determination of the mass concentration (ng/L or g/L) of tyre and road wear particles (TRWP) in water samples, and the mass concentration in suspended solids(g/g).

This document establishes principles for:

— water sample collection

— pre-concentration of TRWP from water

— sample preparation and pre-treatment prior to pyrolysis;

— generation of pyrolysis fragments from the sample; and

— quantification of the generated polymer fragments.

This document is applicable to samples from water

Purpose

Tyre and road wear particles (TRWP) are formed as a result of tread abrasion from the road surface, and subsequent particle release to the environment. TRWP consist of tyre tread particles which include incorporated material from the road surface. TRWP are transported from road surfaces to aquatic environments via stormwater runoff and atmospheric deposition, making water an important exposure compartment. The occurrence of TRWP in surface water, river sediment, and marine environments has been demonstrated by field studies. While existing standards address pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis of TRWP in soil and sediment ( FDIS21396), no standardised method currently exists for the quantification of TRWP specifically in water. TRWP in water present distinct analytical challenges compared with soil and sediment matrices: particle concentrations in surface water are typically in the ng/L to g/L range, requiring collection and preconcentration of large sample volumes; the water matrix can introduce organic co-extractants (e.g., chlorophyll, lignin) that interfere with the vinyl cyclohexene (VCH) marker used for SBR/BR quantification; and TRWP are not homogeneously distributed in the water column due to variable particle density and hydrodynamic sorting. The disparity among published field studies — which have used differing sampling volumes (1L to 10000L), filtration cut-off sizes, and density separation approaches — limits the direct comparability of results. A standardised, water-specific method is therefore required to support environmental monitoring programmes and risk assessment.