PS (polystyrene) can be made into rigid or foam products — in the latter case it is popularly known as the trademark Styrofoam. Styrene monomer (a type of molecule) can leach into foods and is a possible human carcinogen, while styrene oxide is classified as a probable carcinogen. The material was long on environmentalists' hit lists for dispersing widely across the landscape, and for being notoriously difficult to recycle. Most places still don't accept it in foam forms because it's 98% air.
Read more about this here https://www.naraloca.com/post/plastic-recycling-symbol-no-6
This video below show us the recycling of PS works
Nara Loca Abadi is a recycled plastic specialist that concerned about the earth and environment by promoting the use of recycled PET flakes, recycled PET, recycled PP & HDPE granules to various plastic and polyester manufacturers.