Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2′-bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g–1 to µg g–1. Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach from waste disposal sites into groundwater and/or surface waters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol A concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub µg l–1 to mg l–1 and were correlated with the level of economic development.

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Transport and release of chemicals from plastics to the environment and to wildlife

Human exposure to bisphenol A

Plant cyanogenic glycosides.

Baby bottles are often made of polycarbonate plastic. Impurities remaining in the bottle from the monomer bisphenol A can migrate from the plastic bottles into baby food, thereby causing a health concern. Previous migration testing of new baby bottles showed only trace migration levels of the substance. In the present work, polycarbonate baby bottles were subjected to simulated use by dishwashing, boiling and brushing. Migration testing performed with both new and used bottles revealed a significant increase in migration of bisphenol A due to use. This finding might be explained by polymer degradation. Bisphenol A was determined in 200-ml samples of water food simulant by a method based on solid-phase extraction followed by gas chromatography coupled with mass spectrometry. The detection limit was 0.1 microg l(-1). Twelve different polycarbonate baby bottles were tested by filling them with hot water (100 degrees C) for 1 h. The mean bisphenol A level from new bottles was 0.23 + -0.12 microg l(-1), while the mean levels from bottles subjected to simulated use were 8.4 + -4 microg l(-1) (dishwashed 51 times) and 6.7 + -4 microg l(-1) (dishwashed 169 times), respectively. None of the bottles released bisphenol A at levels that exceed the recently established provisional tolerable daily intake (0.01 mg kg(-1) body weight/day) in the European Union.

Increased migration levels of bisphenol A from polycarbonate baby bottles after dishwashing, boiling and brushing

European Union Risk Assessment Report

The migration of bisphenol A from food contact polycarbonate products was investigated by HPLC with a quantitation limit of 0.5ppb. The migration was affected by the test conditions and it increased in the order of water and 4% acetic acid at 60°C, 30min<20% ethanol at 60°C, 30min<water and 4% acetic acid at 95°C, 30min<n-heptane at 25°C, 60min. It decreased sharply after repeated use or when the products were boiled before the tests. Four contravened samples contained 379-599ppm of bisphenol A, but the migration was under 40ppb. Ten commercial products, e. g., infant's tableware, nursing bottles and a measuring cup, contained 5-80ppm and migration was found from only 3 samples at under 5ppb. The migrations of phenol and p-tert-butylphenol from the same samples were also investigated.

https://www.jstage.jst.go.jp/article/shokueishi1960/39/3/39_3_206/_pdf

Migration of Bisphenol A from Polycarbonate Products

The migration of styrene dimers and trimers from polystyrene containers into instant foods and their content in the container were determined by GC and GC/MS. Thirty-two kinds of instant foods, which included Chinese noodles, Japanese noodles (udon), buckwheat noodles (soba), chow mein (yakisoba), spaghetti, soup (miso-soup, minestrone, etc.) and rice (gomokumeshi, chuka-don and gruel) were analyzed. In the whole instant foods, the migration levels of the total trimers ranged from undetectable to 62.4ng/g (0-33.8μg/cup) while dimers were not found. In the case of Chinese noodles, the migration into noodles was higher than that into soup and the total migration level at 30 minutes after adding hot water was 1.5 times higher than that at 10 minutes. In the case of Chinese noodles and soup in EPS (expandable polystyrene) containers, the contents of dimers and trimers in the material of the containers were under 800μg/g, and they did not detect in the foods. Raw or non-fried noodles had a lower migration level than fried noodles even in PSP (polystyrene paper) cups which contained more than 4, 800μg/g of dimers and trimers. The migration during microwave oven cooking was somewhat higher than during hot-water cooking.

https://www.jstage.jst.go.jp/article/shokueishi1960/39/6/39_6_390/_pdf

Migration of Styrene Dimers and Trimers from Polystyrene Containers into Instant Foods

Styrene dimers and trimers in polystyrene were extracted with cyclohexane-2-propanol (1:1) and determined by GC-FID. The analyzed samples were disposable cups, food cases, bowls, trays, cases of yogurt and tofu, and cups of instant noodles, chow mein, spaghetti, etc. All samples contained the dimers and trimers and residue levels were 90-1, 030μg/g (average 380μg/g) and 650-20, 770μg/g (average 9, 210μg/g), respectively. The cyclotrimer, 1-phenyl-4-(1′-phenylethyl) tetralin, accounted for about two-thirds of the residues. The migration test with food simulated-solvents was carried out using three types of polystyrenes containing about 10, 000μg/g of dimers and trimers. High-impact polystyrene released larger amounts of dimers and trimers than general-purpose polystyrene and the migration levels into n-heptane were 44.8μg/cm2 and 0.38μg/cm2, respectively.

Determination of Styrene Dimers and Trimers in Food Contact Polystyrene

The electron spin resonance (ESR) spectrometry spectra of white (WP), black (BP) and red (Capsicum annuum L. var. frutescerns L., RP) peppers each had a principal signal with a g-value of 2.0043, and the intensities of the principal signals were increased not only by γ-irradiation but also by heating. Irradiated RP also showed a minor signal -30G from the principal one, and the intensity of the minor signal increased linearly with increasing dose from 10 to 50kGy. Since the minor signal was observed in RP irradiated at 10kGy and stored for one year, but did not appear either after heating or after exposure to this signal is unique to γ-irradiated RP and should therefore be useful for the identification of γ-irradiated spices of Capsicum genus, such as paprika and chili pepper. The computer simulation of the ESR spectra suggested that the minor signal should be assigned to methyl radical and the principal signal mainly to a combination of phenoxyl and peroxyl radicals. Such minor signals were found in γ-irradiated allspice and cinnamon among 10 kinds of other spices.

Identification of γ-Irradiated Spices by Electron Spin Resonance (ESR) Spectrometry

A simultaneous determination method was developed for 53 polymer additives in polyethylene, i. e., 21 antioxidants, 9 ultraviolet stabilizers, 20 lubricants and 3 plasticizers. All compounds could be identified and quantitated by gas chromatography/mass spectrometry (GC/ MS) using a 5 m long fused silica or stainless steel capillary column coated with dimethylpolysiloxane. The samples were prepared by means of a published procedure for determination by HPLC. Average recoveries of 51 additives spiked at 2 levels (200 and 1, 000, ag/g) were between 70. 0 and 127. 0% except DSTDP and hexacosane. Quantitation limits ranged from 50 to 500, ig/g, depending on the compounds. Nine compounds, BHT, Irganox 1076, Irgafos 168, oleamide, erucamide, palmitic acid, stearic acid, hydrocarbons, DBP and DOP, were found in polyethylene products. The proposed method is satisfactory for the determination of plastic additives in polyethylene products. (Received April 24, 1997)

https://www.jstage.jst.go.jp/article/shokueishi1960/38/5/38_5_307/_pdf

Yoko Kawamura

Papers

Migration of Bisphenol A from Polycarbonate Products

Migration of Styrene Dimers and Trimers from Polystyrene Containers into Instant Foods

Determination of Styrene Dimers and Trimers in Food Contact Polystyrene

Identification of γ-Irradiated Spices by Electron Spin Resonance (ESR) Spectrometry

Simultaneous Determination of Polymer Additives in Polyethylene by GC/MS