Fate of recycled tyre granulate used on artificial turf

Abstract

The production of granulates as infill for artificial turf is able to process 21% of the end-of-life tyres in Europe, approximately 600 million kg per year. In doing so it avoids an annual CO2 emission comparable with the amount that could be absorbed by around 30 km2 of forest. However, dispersal of rubber infill to the environment is perceived as a problem. An amount of 3000–5000 kg granulate per field per year is currently used as underpinning for a European proposal to ban rubber infill as part of the intended restriction on intentionally added microplastics in 2021. By reviewing grey research reports, we found out that the dispersal rates are based on the false assumption that the annual granulate demand for refilling is necessary because of granulate losses to the environment. However, it has been ignored that part of the refill is needed because the infill layer settles and becomes more dense (compaction) and that part of the lost infill is collected and reused on the fields. In combination with unawareness and improper piling of snow in the past, these are the causes of the high estimates of infill dispersal per year. This paper shows the current state-of-knowledge about ELT granulate dispersal and shows that approximately 600–1200 kg refill is required annually to compensate for compaction and for some infill waste on pavements and in drainage sinks. Recommended mitigation measures are containment through optimized field and drainage construction, suitable maintenance equipment and practices and good-housekeeping rules for players and groundkeepers and handling end-of-life pitches. If these recommendations are implemented, the emission of ELT granulates to the environment can be reduced to virtually zero.