Updated evaluation of the migration of styrene monomer and oligomers from polystyrene food contact materials to foods and food simulants

Abstract

Due to the 2011 labelling of styrene monomer as "reasonably anticipated to be a human carcinogen" by the National Institutes of Health's National Toxicology Program (NTP) and the controversy over whether styrene oligomers mimic the physiological effects of estrogen, an updated review of styrene monomer and oligomers in food and food contact materials (FCMs) was performed. The concentrations of styrene monomer and oligomers were determined in 24 polystyrene (PS) products and ranged from 9.3 to 3100 mg kg(-1) for the styrene monomer, 130-2900 mg kg(-1) for the sum of three styrene dimers, and 220-16,000 mg kg(-1) for the sum of six styrene trimers. Foods in contact with PS packaging had styrene monomer concentrations ranging from 2.6 to 163 ng g(-1); dimer concentrations from the limit of quantitation (LOQ) to 4.8 ng g(-1) and trimer concentrations were all below the LOQ (2 ng g(-1)). Diffusion coefficients (Dp) and partition coefficients (K) were also calculated for styrene dimers and trimers. The results presented here indicate that styrene monomer concentrations in foods have not significantly changed since the 1980s and monomer concentrations in food packaging quantified in this study were all below USFDA limits. Although styrene dimers and trimers are present in higher concentrations in PS FCMs than the monomer, their migration to food is limited because of their high K values (4 × 10(2) to 2 × 10(6)) and their low diffusion coefficients in PS products. Additionally, diffusion coefficients calculated using USFDA-recommended food simulants and Arrhenius plots describing the temperature dependence of styrene dimers and trimers can be used in future calculations of dietary intake of the styrene oligomers.

Evaluation of potential health effects associated with occupational and environmental exposure to styrene – an update

“…The high concentration of styrene in the composite sample of herbs and spices is attributed to the naturally high concentrations of styrene in cinnamon. In a recent updated evaluation of styrene migration from polystyrene food contact materials, Genualdi, Nyman, and Begley (2014) measured styrene concentrations in wrapped food products and chewing gum (which contains styrene-butadiene as a gum base). The generally similar styrene concentrations reported by Cao, Sparling, and Dabeka (2016) in similar food items are provided for comparison in Table S20.…”

“…Styrene in food packaging materials may volatilize and be inhaled by the consumer, or leach into foods and be ingested. Migration of styrene from styrenic (and other) food-contact materials is a recognized means of substance entry into packaged foods and the subject of national and international regulation (Arvanitoyannis and Bosnea 2004;Begley et al 2005;Genualdi, Nyman, and Begley 2014;Marc and Zabiegala 2017). FDA regulates the amount of styrene allowed in food grade polystyrene at 1% by weight (10,000 mg/kg) for contact with non-fatty foods and at 0.5% by weight (5000 mg/kg) for contact with fatty foods (U.S. FDA, 2017).…”

“…Under the same regulation, rubbermodified polystyrene basic polymers may not exceed 0.5% by weight of total residual styrene. Measured styrene concentrations in packaging materials and disposables purchased in the Washington, D.C. area (Genualdi, Nyman, and Begley 2014) are summarized in Table S21; residual styrene levels in products provided by seven resin supplier companies in 2012 are presented in Table S22.…”

Challenges of including human exposure to chemicals in food packaging as a new exposure pathway in life cycle impact assessment

“…LCA practitioners may be able to obtain more information about the chemical additives used in a package from a study commissioner to develop LCI. For this proofofconcept study, however, the list of chemicals in HIPS packaging material was collected from a US FDA study (Genualdi et al 2014), regulatory documents from the European Commission (EC) (Hoekstra et al 2015), and a technical report sponsored by the Food Standards Agency (Bradley and Coulier 2007).…”

Simultaneous determination of 22 phthalate esters in polystyrene food‐contact materials by ultra‐performance convergence chromatography with tandem mass spectrometry

“…PS is widely used in various common consumption products such as food containers, toys, home furniture, and building materials . As additives, PAEs in PS are not chemically bounded to the plastics, and they can easily release from plastic products and migrate into the foods .…”