Polystyrene is a polymer and consists of only one type of monomer, namely styrene. Styrene is a by-
product of oil, which is used for a number of different types of plastics and not just polystyrene. Did
you know that styrene occurs naturally in cinnamon, coffee beans, strawberries and wheat? Raw
material producers covert the styrene into polystyrene, which is then converted into EPS raw
materials. The producers of expanded polystyrene products use steam to heat the EPS beads. This
causes the EPS beads to expand into loose foamed EPS beads that are up to 50 times their original
volume. So EPS is made of 98% air.
New products of EPS can (and do) contain up to 50% regranulated material. Of course, the amount
depends on the product itself, since the regranulated pearls do not expand during the moulding
process itself. Large parts of the EPS produced in Denmark, Germany and the Netherlands contain
significant parts of recycled EPS pearls.
Even before the EPS leaves the factory, it can be part of circular loops. When the EPS raw material is
foamed and shaped, faulty production can occur. For example, packaging can break or otherwise be
damaged, while EPS blocks for insulation use are cut and adapted. All the excess EPS is granulated
and transformed into loose EPS pearls, which are part of the production of new packaging or
EPS insulation can similarly be collected for reuse or recycling. EPS insulation does not lose its
properties over time, so EPS insulation can be taken down and then reinstalled. As with other
materials, reuse is preferable to recycling. Of course, you have to make sure that materials have the
relevant properties¹, and it is not always easy to determine the compressive strength of an EPS plate
you want to reuse.
¹ in f.i. Germany and Netherlands it is not allowed to reuse EPS insulation products fabricated before 2016.
When an EPS product cannot be reused or if it’s broken, then there are different options. In the EPS
industry, members have been taking back EPS from their customers since the eighties and nineties of
last century. When the packaging or building waste is pure, it can be regranulated and reused just as
with waste and cut off from the original production. The EPS beads can be regranulated a number
several times in this way before being recycled by being melted down. The granulation process itself
automatically separates EPS beads that cannot be recycled. Many EPS building insulation products
contain (much) recycled EPS, mostly from packaging but more and more also from building
However, not all used EPS can be mechanically recycled. If the EPS packaging or building waste is too
dirty, it cannot be regranulated and the EPS pearls cannot be recycled directly in production. If
possible the material must then be sent for recycling by melting to (General Purpose) PS. The
collected EPS will first be compressed and made into blocks being reprocessed into a new
polystyrene regranulate which is compatible and comparable both to a number of virgin GPPS materials as well as other PS recyclades that are used for new products. We often see it used for XPS
Other EPS products such as car seat parts and bicycle helmets have a long service life and can be
used for years. Once they are worn out (or the bike helmet has mitigated a fall against a curb) the
EPS can be collected and recycled. For some EPS packaging, such as packaging for organs or fish
boxes, it is not allowed to be mechanically recycled, in which case it will be sent directly for recycling
Once the EPS is collected, there are also alternative ways to go. Sometimes EPS is collected for
recycling in the production of EPS concrete. The packaging is granulated into several pieces and is
included in the production of the material. Since the alternative to recycled EPS is new EPS pearls, it
may be the most environmentally appropriate solution, rather than collecting and converting into
new EPS raw materials, which must then be foamed into EPS for use with EPS concrete.
Thus, EPS is actually permanently recyclable, as it can be recycled indefinitely and even EPS that has
been contaminated can be cleaned and upcycled into new EPS. And be sure: the EPS industry
achieves very high recycling rates!