2 min

Testing environmentally friendly infill in artificial turf pitches

Every day, millions of people play on artificial sports pitches infilled with plastic or rubber granules. The infill makes the fields more durable and weather-resistant and provides shock absorption and traction. The use of plastic or rubber infill in artificial turf has increased over the last 10-15 years, as the demand for all-weather pitches has grown.

Despite the major advantages of artificial turf pitches in terms of among others availability and maintenance, there are also drawbacks in terms of environmental impact. Plastic material used as infill can contribute to major environmental problems. In Norway for example, the Norwegian Environment Agency has estimated that plastic-containing filler material, or rubber granules from artificial turf, is believed to be the second largest land-based source of microplastics. About six per cent of this filler material eventually ends up outside the pitches, amounting to an emission of microplastics of about 6,000 tonnes per year in Norway.

Kiwa has tested the use of more environmentally friendly or organic filling. What challenges do these alternatives to rubber or plastic infill present? And how easy is it to replace plastic infill with organic material? We asked Gry Eian, head of Inspection East at Kiwa Norway.

Stricter environmental requirements

In July 2021, a new EU regulation for artificial turf pitches with rubber granules has been introduced. The regulation applies to polycyclic-aromatic hydrocarbons (PAHs) in granules or mulches used as infill material in synthetic turf pitches or in loose form on playgrounds or in sport applications, such as golf courses, athletic arenas or horse arena footings (source: EU). It prohibits the placing on the market and use of granules and mulches as infill if they contain more than 20 mg/kg of the sum of the eight PAHs. Granules or mulches placed on the market also have to be batch labelled to ensure safe use. The new rules apply from 10 August 2022 (source: ECHA).

The regulation is important for reducing emissions of microplastics, and applies to all turf pitches with plastic-containing loose filling material such as rubber granules. The purpose of the regulation is to prevent the discharge and spread of microplastics.

Challenges with organic filling

The spotlight on sustainability and green technology has made it relevant to find environmentally friendly alternatives to plastic infill. Coconut, olive kernels, cork, rice and bark are materials that have been tested.

Gry Eian emphasizes that using alternatives to rubber granules presents its own challenges. She says: “Each material will have distinctive properties that affect the functionality of the substrate. Friction and shock absorption are important. Rubber granules have an elasticity that contributes to shock absorption. It will not necessarily be a property that is present in organic filling materials. A material such as cork will, for example, float up more easily if the pitch is filled with rainwater. This places greater demands on the drainage of the facility. Cork will also freeze more easily, and affect the functionality of the substrate and availability of the pitch in the winter.”

Testing to avoid potential problems

Using organic filling material will eventually lead to a rotting process. Gry says: “Consideration must be given to whether such a process could in the long term lead to damage to the artificial grass, so that the cover has to be changed more often than is the requirement today”.

“We have several assignments on pitches with infills that are not rubber-based, and have gradually built up expertise in the challenges such materials bring with them. Regardless of the type of infill material used, it is worth noting that the more the subsurface is tested before the turf is laid, the more potential problems can be avoided.”, tells Gry.

Expert in testing and certification sport pitches

Gry emphasizes that Kiwa has expertise in testing and certifying several types of sports flooring: “We test, among other things, athletics tracks, indoor sports floors and tennis courts. Kiwa Norway (Norwegian) has extensive experience with testing according to the requirements imposed by the authorities, and is one of the main players in Norway that prepares valid test reports in accordance with government's guidelines”. 

Also outside Norway, Kiwa is one of the leading parties in testing and inspecting sports facilities. Read more on the website of Kiwa Netherlands.