Derivation of safe health-based exposure limits for potential consumer exposure to styrene migrating into food from food containers

Abstract

Residual styrene present in polystyrene food packaging may migrate into food at low levels. To assure safe use, safe exposure levels are derived for consumers potentially exposed via food using No/Low Adverse Effect Levels from animal and human studies and assessment factors proposed by European organisations (EFSA, ECHA, ECETOC). Ototoxicity and developmental toxicity in rats and human ototoxicity and effects on colour discrimination have been identified as the most relevant toxicological properties for styrene health assessments. Safe exposure levels derived from animal studies with assessment factors of EFSA and ECHA were expectedly much lower than those using the ECETOC approach. Comparable safe exposure levels were obtained from human data with all sets of assessment factors while ototoxicity in rats led to major differences. The safe exposure levels finally selected based on criteria of science and health protection converged to the range of 90-120 mg/person/d. Assuming a consumption of 1 kg food/d for an adult, this translates to 90 mg styrene migration into 1 kg food as safe for consumers. This assessment supports a health based Specific Migration Limit of 90 ppm, a value somewhat higher than the current overall migration limit of 60 ppm in the European Union.

Keywords: AF; Assessment factors; DNEL; Derived No Effect Level; ECETOC; ECHA; EFSA; EH; EPS; European Centre for Ecotoxicology and Toxicology of Chemicals; European Chemicals Agency; European Food Safety Authority; Exposure via food; Food and Drug Administration of the U.S. Department of Health and Human Services; GPPS; HED; HIPS; JECFA; Joint FAO/WHO Expert Committee on Food Additives; LOAEL; LWAE; Low Adverse Effect Level; MA; MAK; Maximale Arbeitsplatz Konzentration; NOAEL; No Adverse Effect Level; Ototoxicity; PGA; PS; RAC; RAR; REACH; RISK Assessment Committee of ECHA; Reference Dose; Registration, Evaluation, Authorisation and Restriction of Chemicals; RfD; Risk Assessment Report of the EU; S; SEL; SML; SO; SSC; Safe exposure levels; Specific Migration Limit; Styrene; Styrenics Steering Committee; TDI; TWA; Tolerable Daily Intake; UK; US FDA; United Kingdom; WHO; World Health Organisation; assessment factor; body weight; bw; epoxide hydrolase; expanded polystyrene; general purpose polystyrene; high impact polystyrene; human equivalent dose; lifetime weighted average exposure; mandelic acid; phenylglyoxylic acid; polystyrene; safe exposure level; styrene; styrene-7,8-oxide; time weighted average exposure.