Rubber crumb made from car tyres is a hit!
In the Netherlands, the vast majority of used car tyres is recy-
cled into rubber crumb. For years, this rubber crumb has been
used in playground tiles, athletics tracks and as infill for artifi-
cial turf football pitches. The use of rubber crumb in artificial
turf pitches helps prevent injury and, in combination with the
total artificial turf system (underlay and surface), ensures ex-
cellent playing characteristics, even in the long term. At the
present time, the Netherlands has some 400 pitches with rub-
ber crumb infill made from shredded tyres (about 80% of the
total number of artificial turf football pitches).
Safe for people and the environment
Independent research shows that playing on artificial turf with
rubber crumb infill made from recycled car tyres does not
pose any risk to human health or the environment. In the past
year, various reports have been published on the use of rub-
ber crumb. This led to uncertainty regarding the health and
environmental aspects among the parties involved (e.g. muni-
cipal councils and sports clubs). To banish this uncertainty, an
independent study was conducted by INTRON Certificatie B.V.,
ISA-Sport, TNO and Industox Consult. This brochure presents a
summary of the study results.
The study The study consisted of a literature study and experimental stu-
dies in the field and the laboratory.
The literature study comprised the consultation of 17 interna-
tional study reports and 13 other sources, and Dutch and Euro-
pean legislation, directives and guidelines were also examined.
There was also a literature study of allergies resulting from skin
contact with rubber products.
The experimental health study focused on the absorption of
polycyclic aromatic hydrocarbons (PAHs) after skin contact with
rubber crumb. Sportspeople were tested to measure the pre-
sence of PAH conversion products in the urine after intensive
contact with rubber crumb on an artificial turf field. The results
were then compared to the internationally accepted health
threshold values for exposure to PAHs.
Laboratory study
In the laboratory, a climate chamber was used to conduct
weathering tests on artificial turf systems with rubber infill
made from car tyres. The weathering process of the rubber was
accelerated in order to measure the effect of weathering on the
leaching of zinc. Zinc leaching was measured for rubber infill
made from passenger car tyres and commercial vehicle tyres.
Both systems without an underlayer and with a lava underlayer
(10 cm) were tested.
Organisations involved in the study
Ministries Health, Welfare and Sports (WVS), Housing,
Spatial Planning and the Environment (VROM) the National
Institute for Public Health and the Environment (RIVM)
Sports organisations the Royal Netherlands Football Associ-
ation (KNVB), the Dutch Association of Professional Football
Players (VVCS) and the Netherlands Olympic Committee/
Netherlands Sport Confederation (NOC*NSF)
Official certification institutes INTRON and ISA Sport
Business manufacturers of artificial turf fields
Sector organisations the Tyre and Environment Association
and the Tyre and Wheel Trade Association (VACO)
Field study
The field study consisted of an analysis of the drainage water
from five artificial turf fields to ascertain exactly how much zinc
leaches out of an artificial turf field with infill made from rubber
crumb from car tyres.
HealthIn order to assess the health risks, it is important not only to
look at the chemical substances present in rubber, but also at
the actual bio-availability of these substances for humans. In
their assessment of the risks posed by these substances, the
scientists used internationally accepted threshold values.
Swallowing
The content of heavy metals in rubber crumb meets the Euro-
pean toy standards, which is why the scientists concluded that
swallowing or skin contact with rubber crumb containing these
metals poses no health risk. Canadian and Norwegian scientific
studies confirm the conclusion that swallowing rubber crumb
does not lead to health risks.
Inhaling
According to foreign literature, no health risk is posed when
rubber crumb is applied on indoor and outdoor sports fields. In
the autumn of 2006, the Gelderland Midden Area Health Autho-
rity and the RIVM conducted an air quality study on an artificial
turf field with rubber crumb infill made from car tyres. Fine dust
particles, polycyclic aromatic hydrocarbons (PAHs), heavy me-
tals, volatile organic hydrocarbons and nitrosamines were all
well below the health threshold values.
Skin contact
Studies have shown that skin contact with rubber does not lead
to any health risk. Experimental tests conducted by INTRON and
Industox studied exposure to substances that may migrate from
the rubber crumb to the skin, such as PAHs. Their scientists con-
cluded that the absorption of PAHs when playing on an artificial
turf pitch in an exposure scenario with relatively long-term and
intensive skin contact with rubber crumb is difficult to ascertain.
If any substances were absorbed at all, the levels were extreme-
ly limited when compared with absorption or intake from other
sources (e.g. living environment and diet). Danish and Canadian
scientific studies confirm this conclusion.
Conclusions regarding health
On the basis of the completed studies, the scientists at INTRON
have concluded that there is no significant risk to health when
playing on an artificial turf field with rubber crumb infill made
from recycled car tyres.
The environmentThere are no statutory environmental standards for rubber
crumb in sports fields. As a frame of reference, the scientists op-
ted for the standards laid down in the Building Materials Decree
and the Decree and Regulations on Soil Quality. They also asses-
sed the leaching levels of substances for a period of 100 years.
Conclusions regarding the environment
The composition of the organic components in rubber meets
the threshold values of the Decree on Soil Quality. The lea-
ching level of heavy metals, apart from zinc, is well below the
threshold values laid down in the Decree on Soil Quality.
In the long term (60 to over 100 years), the leaching of zinc from
an artificial turf system (artificial turf field with a lava/sand un-
derlay) with rubber crumb infill made from car tyres will exceed
the policy standard for the emission of zinc into the soil, and
after 50 to 95 years, it will also exceed the MTT for added dis-
solved zinc into the surface water. The leaching of zinc from the
rubber infill does not result in any significant contamination of
either lava or drainage sand underlays.
The zinc concentration in the drainage water from four- to six-
year-old fields is lower than the concentration in rainwater. The
results of the measurements taken in the field did not exceed
the standard for added dissolved zinc in surface water.
The scientists concluded that leaching for the technical lifetime
of an artificial turf field (about 10 to 15 years) does not lead to
an excess of the threshold values for dissolved zinc in surface
water or the derived threshold value from the Decree on Soil
Quality for the emission of zinc into the soil.
ConfidenceThe Tyre and Wheel Trade Association (VACO) and the Tyre and
Environment Association/RecyBEM (Association of Manufactu-
rers and Importers of Passenger Car Tyres) are delighted with
the conclusions of the independent study of the health and
environmental aspects of rubber crumb made from car tyres.
The fact that the conclusions are endorsed by the Ministry of
VROM and the RIVM boosts confidence.
The use of rubber crumb made from car tyres in artificial turf
fields is a high-quality application and therefore makes a posi-
tive contribution to Dutch environmental policy. Compared to
newly produced rubber crumb, significant savings are made
on raw materials, energy and CO2 emissions, so the use of rub-
ber crumb made from recycled tyres is and will continue to be
a safe and acceptable application in many respects.
The benefits of artificial turf
ÜCan be played on at all times (regardless of weather conditions).
ÜLess use of space since fields can be used more intensively.
ÜLow maintenance.
The benefits of rubber crumb made from recycled
car tyres
ÜDemonstrably safe for humans and the environment.
ÜA good-quality product.
ÜGood long-term playing characteristics (assuming a good underlay and
surface structure).
ÜHighly resistant to wear and tear (long lifetime, regardless of weather
conditions).
ÜArtificial turf fibres hardly worn by rubber crumb.
ÜExcellent price/quality ratio.
ÜSavings on raw materials and energy compared to new material.
ÜEncourages the high-quality application of shredded car tyres.
ÜLower CO2 emissions because it is a recycled product and is partly natural
rubber.
The total amount of zinc that leaches from all artificial turf
systems with car tyre rubber in the Netherlands is only a
fraction of the total zinc impact on our environment. Most
of that impact (>99.99%) is caused by agriculture, industry,
wastewater, traffic and building materials such as zinc gut-
tering. Tyre manufacturers have been cutting the use of zinc
in new tyres for years, so the amount of zinc that leaches
out of rubber crumb made from car tyres will continue to
fall in coming years.
Vereniging Band & Milieu / RecyBEM
(Tyre and Environment Association)
Loire 150 | 2491 AK The Hague
The Netherlands
T +31 (0)70 444 06 32
F +31 (0)70 444 06 91
www.bandenmilieu.nl
Vereniging VACO
(Tyre and Wheel Trade Association)
Archimedesweg 31 | 2333 CM Leiden
The Netherlands
T +31 (0)71 568 69 70
F +31 (0)71 568 69 71
www.vaco.nl
The results of the INTRON studies are available on
www.bandenmilieu.nl and www.vaco.nl.
The organisations mentioned above would be pleased
to provide additional information.
Although this publication has been compiled with the greatest of care, the
organisations mentioned in it and other parties concerned can accept no
liability whatsoever for the use of its contents.