An article published on November 9, 2018, in the peer-reviewed journal Food and Chemical Toxicology, reported on the “risk assessment for migration of styrene oligomers into food from polystyrene food containers.” Heinz-Peter Gelbke from the consultancy CinTox, France, together with nine other consultants and industrial scientists, addressed dimers and trimers of styrene (CAS 100-42-5) as “important potential components” of non-intentionally added substances (NIAS) in “polystyrene used for food packaging.” Risk assessment of NIAS is required by the Commission Regulation (EU) No 10/2011 on food contact plastics. 

The authors summarized that these substances are “not genotoxic in vitro [(FPF reported)], and there is good evidence that they are not endocrine disruptors.” They performed hazard characterization using the Threshold of Toxicological Concern (TTC) approach and “the No Adverse Effect Level (NOAEL) of 1 mg/kg bw/d in an oral rat study during pregnancy and lactation.”  To derive the “likely human exposure,” they relied on the concentrations measured in food simulants or food and performed “the probabilistic FACET [(Flavours, Additives, and food Contact materials Exposure Task)] exposure estimation based on dimer and trimer concentrations in polystyrene and their potential for migration.” 

The margin of safety, calculated “as the relation of potential consumer exposure and the ‘safe’ exposure level,” was “above 1” in all cases “apart from migration with 95% ethanol which is no longer recommended as an official food simulant for overall migration into fatty food.” Based on their analysis, the authors concluded that dimers and trimers of styrene migrating from polystyrene food packaging “present a low risk for consumers.”

References 

Gelbke, H.-P., et al. (2018). “Risk assessment for migration of styrene oligomers into food from polystyrene food containers.” Food and Chemical Toxicology (published November 9, 2018). 

Gelbke, H.-P., et al. (2018). “Oligomers of styrene are not endocrine disruptors.” Critical Reviews in Toxicology 48:471-499. 

Nakai, M., et al. (2014). “Genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food.” Toxicology Reports 1:1175-1180.

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