Synthetic yarn producers, tufters and installers are all working very hard to improve their products to prevent authorities having to introduce legislation in an attempt to curb secondary microplastic pollution. Here is a status report.
In September this year, the European Commission adopted a resolution that will ban the sale of intentionally added microplastics from 2031. This means that polymeric infills like SBR, TPE or EPDM that fall within the definition, effective October 2031, can still be used in fields that are already installed but can no longer be traded. The same applies to biodegradable infills that are produced from a polymer.
The EU considers infill particles to be a microplastic when the dimensions are smaller than 5 mm.
Secondary microplastic pollution is caused through wear or degradation of polymeric materials. In respect to synthetic turf systems, this applies to the yarn and the backing as well as most glue tapes. Any fragment of these components that is smaller than 15 mm and that is found outside the field perimeter is considered to be pollution.
Where microplastic pollution from polymeric infills was mainly an issue to be addressed by users of synthetic turf football, rugby, American football or Gaelic fields, to name a few, secondary microplastic pollution from synthetic turf affects any owner of a synthetic turf product.
Problem positioning
The synthetic turf industry at large is of the opinion that modern synthetic turf products and systems that have been approved by the various sports governing bodies are far superior to systems that were introduced only a decade ago. Progress made by the masterbatch producers as well as the more stringent requirements set by, amongst others, FIFA, FIH and World Rugby regarding the footfall or UV-impact modern synthetic turf systems are expected to handle, has significantly reduced the wear these systems experience. However, as the technical director of the EMEA Synthetic Turf Council (ESTC) recently pointed out, “The industry is being judged on what is happening today, based on fields sold in the past.” And yarn wear is inevitable.
A synthetic turf hockey surface contains 75,000 km of yarn. A natural turf surface that is reinforced by synthetic turf fibres stitched into the surface, in general, contains 47,500 km of yarn. According to the ESTC, a synthetic turf football field contains approximately 10 tonnes of yarn. However, with mineral-filled synthetic turf systems as well as non-filled systems being viewed as the future of synthetic turf, this number can soon be outdated. Both solutions have a higher yarn density than traditional systems, with some non-filled systems even containing three to four times the volume of yarns compared to a mineral-filled system.
Wear pattern
Two main causes have been identified that could result in secondary microplastic pollution from synthetic turf: tuft loss, either as a result of the installation or failure to adhere to the stipulated infill depths, and yarn wear.
As every field is used differently, not all areas suffer yarn wear at the same rate. The ESTC has now commissioned the Institut für Landschaftsbau, Sportfreianlagen und Grünflächen, University of Osnabruck, to visit older sports fields throughout Europe to collect samples so that the levels of yarn wear can be measured and quantified.
Yarn wear predominantly starts between six to eight years and becomes more intensive after 10 years as fibres weaken. The impact of UV, (incorrect) usage of the field as well as (incorrect or insufficient) maintenance are known influencers of this process.
According to the ESTC, high-use areas of the field like the goal mouth may lose up to 12% of fibre after 10 years. The moderate-use areas (e.g., the central axis of the field) may lose up to 2% of fibre after 10 years. The low-use areas (the sections next to the sidelines) may suffer less than 0.5% fibre loss after 10 years.
The European Standards Committee (CEN) is currently working on establishing a method to determine the mass loss. From what we have been told, Sportsfields.info understand that there are two methods currently being discussed. One applies to the carpet itself, while the other one considers the entire system. Depending on which option will be adopted, such a standard will be advertised for approval either next year or three years from now. The reason for the difference in time is that NEN-EN 15330 Surfaces for Sports Areas – synthetic turf and needle-punched surfaces primarily designed for outdoor use part one (General) – run on a one-year update cycle, while the review or update of part six (Components) has a three-year cycle.
What can be done?
There are already many solutions available that can help prevent secondary microplastic pollution from synthetic turf. The easiest one is to reconsider the need for synthetic turf over any option available. Synthetic turf provides a solution in places that lack the geographical, climate, financial or manpower requirements to affordably install or maintain a safe and quality sports surface that can handle the projected climate or footfall.
Selecting the correct and right quality product will also make a difference. Woven carpets vs tufted carpets, a secondary coating of polyurethane or latex, the quantity UV stabilizers used, the fibre shape or tensile strength of the fibres or number of Lisport XL cycles the system was subjected to: all these say something about how much or how fast the system will start contributing to secondary microplastic pollution.
Where synthetic turf is inevitable, tuft loss during installation can be reduced by limiting the number of carpet cuts. For example: Amsterdam Municipality has opted to use a marking robot at one of its sports complexes over having field markings cut into the surface.
There is also a wide range of risk management measures available. Many of these were introduced once the debate on microplastic pollution from intentionally added microplastics heated up, and have already been adopted by FIFA and World Rugby, and, as such, been added to their manuals. CEN TR-17519 lists most of these measures.
Last but not least, regularly removing the microplastics that have been building up inside the carpet can be considered. ESTC estimates that one square metre of turf can hold approximately 500,000 microplastic particles by the time it has to be removed.
Vacuuming the carpet can provide a solution. As the European Commission has accepted a drive by the textile industry to fit 1 micron filters in all washing machines to trap fibre wear from clothing as a self-regulating solution, the mandatory vacuuming of synthetic turf could certainly help prevent any problem. Asked about the recommended frequency, Sportsfields.info was told by industry insiders that a frequency of at least twice a year is highly recommended.
The future?
Ever since the industry woke up to the message the EU sent in 2016 that (secondary) microplastic pollution from synthetic turf is problematic, it has started developing solutions and alternatives. More organic infills and (partly) biobased synthetic turf yarns have already entered the market and there is certainly more to come.
Yet, it is also proposed to make it mandatory to replace a synthetic turf field after 10 years, irrespective of the possibility of adding (several) more years to its lifespan, thanks to its correct use and the maintenance conducted. The argument is made that synthetic turf yarns start wearing after six years, and that after 10 years, such wear would become excessive. Replacing the carpet in time would prevent such wear entering nature eventually.
Limiting the lifetime of synthetic turf to a maximum of 10 years could make it become financially unviable for some. However, the industry is also busy drafting plans that could see the introduction of completely new financing concepts.
Sportsfields.info will continue closely monitoring these developments and will report on these whenever possible.