How can you recycle styrofoam

Recycle styrofoam with or without flame retardants

Disposal situation and classification

2014 was kind of a fateful year for styrofoam as an insulation material. The addition of the flame retardant hexabromocyclododecane (HBCD), which was common up until then, resulted in poisonous bromine vapors, which had consequences for both incineration and recycling. HBCD has been banned since 2015, but substitutes that also contain bromine are added to the newer polystyrene.

The recycling of untreated styrofoam is possible. Full-fledged raw material for a new production can be obtained from old styrofoam. This styrofoam may and can also be disposed of in broken and shredded form in the yellow sack in the separate waste disposal. Styrofoam enriched with flame retardants must be sorted according to type and delivered to collection points for recyclable materials.

Recycling methods and technical status

Styrofoam can be shredded and returned to its original granular state through a process known as extrusion. It is suitable for re-foaming and re-manufacturing of Styrofoam or Styrodur.

Removed strips and panels can be shredded. The mechanically produced granulate cannot be re-foamed. It can be used as a bulk sealant and as an additive for some types of concrete.

A very young process will be tested for the first time on an industrial scale this year (2018). The styrofoam is dissolved in a chemical solution. This can happen even before it is transported for reprocessing. Additional chemical additives can isolate foreign substances such as flame retardants. The remaining pure granulate can be foamed again. This process solves an additional problem of recycling. It reduces the volume of styrofoam by up to fifty times.

The discovery of a biological recycling route in the US in 2015 has not yet reached market maturity. Ordinary mealworms “eat” styrofoam and use it to produce carbon dioxide and rotting feces. This discovery shows a similarity to some bacterial strains that were tested and considered for the disposal of the plastic bodies of the former cars from the GDR, the Trabants.

Effort and costs for disposal and recycling

Styrofoam, like the related Stryrodur, is one of the problem children in waste management. Only selected waste incineration plants with special permission are allowed to burn polystyrene with flame retardants. The costs for this vary by several hundred percent for Styrofoam and Styrodor.

Old styrofoam stocks cannot be reversed. In order not to create a new load, polystyrene should only be used as an insulating material, or if not fire-resistant enough, it should not be used at all. Polystyrene does not biodegrade without light

As insulation materials, you can replace styrofoam with mineral wool. In terms of price, that makes only a small difference and makes up for the effort at disposal at the latest.

Author: Stephan Reporter
Article image: Talita Nicolielo / Shutterstock
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