Polystyrene (PS)
Cities measured
87
Detected in
87 / 87
Highest
2.8 particles/L — Jakarta
Overview
Polystyrene — both solid and expanded (EPS/Styrofoam) — is brittle and fragments rapidly in the environment. PS microplastics are among the most commonly detected plastic types in surface water.
Health Relevance
Polystyrene contains styrene — an IARC Group 2A probable human carcinogen — which can leach from PS particles, particularly in hot liquids. PS nanoparticles show neurotoxic effects in rodent studies. PS additives include flame retardants (HBCDD).
Regulatory Limits
Drinking Water Directive 2020/2184
No regulatory limit. Styrene monomer limit: 25 μg/L in EU drinking water (food contact migration).
Controversy & Contested Science
The EU Single-Use Plastics Directive (2019) banned EPS cups and food containers from 2021, but compliance varies significantly across member states. The building industry's use of EPS insulation foam — which fragments and leaches into stormwater from construction sites and building facades — is largely unregulated from a plastics pollution perspective. An estimated 23 million tonnes of EPS building insulation is installed in European buildings, representing a substantial long-term microplastic source that no current directive addresses.