Quality and safety aspects of reusable plastic food packaging materials: A European study to underpin future legislation

The objective of this study was to develop a comprehensive package of quality assurance criteria for use by industry and regulatory authorities for ensuring the quality and safety-in-use (sensory, microbiological and chemical) of reused plastics for food packaging. The study included thermal degradation effects, flavour carry-over caused by flavour and off-flavour substances, the influence of washing processes on the materials, and the efficiency of washing processes in removing offflavour substances and surrogate substances representing misuse chemicals as might be put in bottles by consumers. The microbial safety of the refillable plastic articles in relation to commercial washing processes and the industrial procedures applied has also been investigated. Lastly, the suitability of laboratory procedures using strips of bottle material for predicting the sorption and washing properties of refillable plastic bottles has been studied. In general it is concluded that reuse of the articles does not significantly influence any of the properties investigated. Neither the chemical, physical nor surface properties seem to be significantly influenced by repeated washing. It can be concluded, however, that it is very likely that most of the articles investigated will cause flavour carry-over to a new filling if they are contaminated with strongly flavoured products. Finally it can be concluded that the procedures evaluated can serve as a basis for future legislation on refillable articles, but for several procedures (like quick predictive testing with strips) more investigation is required to create a more solid basis.     

Safety and quality of plastic food packaging materials: validation of a modified chemical inertness test method for refillable poly(ethylene terephthalate) bottles

The increased use of refillable poly(ethylene terephthalate) (PET) bottles as packaging for soft drinks has prompted us to investigate the effect of sorption of artificially introduced chemical contaminants into refillable PET bottles in order to establish a practical and easy-to-apply test procedure to evaluate their chemical inertness. For this evaluation, quick laboratory procedures, which focus on the interaction of PET bottle wall strips in place of actual bottles with a selection of model contaminants representing the myriad of chemicals, are proposed. The first objective of this study was to validate a modified quick chemical inertness test method for refillable bottles by comparing the results of sorption into PET strips with those of tests using actual PET bottles. A further objective was to investigate the stability of refillable PET bottles which were stored under unfavorable conditions, in relation to the chemical inertness behavior of the material. The results indicate the suitability of the modified quick test as it satisfactorily simulates contamination of refillable PET bottles. Moreover, storage of these bottles under unfavorable conditions does not have an adverse effect on the chemical inertness behavior of the plastic material.     

Identification and quantification of the migration of chemicals from plastic baby bottles used as substitutes for polycarbonate

The results of a study on the analytical identification and quantification of migration of chemicals from plastics baby bottles found in the European Union market made of materials that are now present as substitutes for polycarbonate (PC) are reported. A total of 449 baby bottles with a focus on first age or sets of bottles were purchased from 26 European Union countries, Canada, Switzerland and the USA. From this collection, which contained several duplicates, a total of 277 baby bottles were analysed. The materials included different types of plastic such as PC, polyamide (PA), polyethersulphone (PES), polypropylene (PP), but also silicone, and from the United States a co-polyester marketed under the trade name Tritan?. The bottles were subjected to the conventional migration test for hot fill conditions, i.e. 2?h at 70°C. The simulant used was that specified in European Union legislation (2007/19/EC) for milk, i.e. 50% ethanol. In a first phase 1, migration was conducted since the scope of this investigation was a screening rather than a true compliance testing check. Second and third migrations were performed on selected articles when migrated substances exceeded limits specified in the legislation. In order to verify some materials, a portion of the bottle was cut to run an FT-IR fingerprint to confirm the nature of the polymer. The migration solutions in general showed a low release of substances. Results showed that bottles made of PP and silicones showed a greater number of substances in the migration solutions and in greater quantity. Chemicals from PP included alkanes, which could be found in >65% of the bottles at levels up to 3500?μg?kg?1; and benzene derivatives in 17% of the baby bottles and found at levels up to 113?μg?kg?1. Some substances were found on a regular basis such as plasticisers, esters and antioxidants (e.g. tris(2,4-di-tert-butylphenyl)phosphate, known as Irgafos 168. Some substances found were not included in the Community positive list, which means that those should not be found even in the first migration. Such substances included 2,6-di-isopropylnaphthalene (DIPN), found in 4% of the bottles at levels up to 25?μg?kg?1, 2,4-di-tert-butyl phenol (in 90% of the bottles at levels up 400?μg?kg?1). Moreover, bisphenol A (BPA) was detected and quantified in baby bottles made of PA, but limited to one brand and model specific (but labelled BPA free). Results for baby bottles made of silicone also indicated the presence of components, e.g. potentially coming from inks (benzophenone, diisopropyl naphtahalene - DIPN, which could come for example from the presence of instruction leaflets in the bottles). In the case of silicone, phthalates were also found in relevant concentrations, with levels for DiBP and DBP from the first migration test of 50-150?μg?kg?1 and DEHP at levels 25-50?μg?kg?1.     

Polycarbonate baby bottles: study of the release of Bisphenol A

Recently, it has been demonstrated that the main Bisphenol A (BPA) release is a degradation process originated by the contact between detergent and polycarbonate (PC) at high temperatures. EU Laws for food contact materials authorize the use of BPA for food contact PC articles (some for the use of young children), and consequently, the degradation process should be taken into account when testing PC articles. In the present study, two types of samples were assayed, baby bottles that have previously undergone some migration assays and new baby bottles of a specific brand in order to test the degradation of not previously used articles. The tests were performed under different conditions and using two types of detergents. To quantify BPA, a high-performance liquid chromatographic system with fluorescence detector was used. The method was validated, and satisfactory results were achieved. Data obtained indicated that the trademark is a substantial factor in the level of BPA release from PC polymer; besides a great dispersion between samples of the same batch independently of the detergent and concentration employed used was found. On the other hand, for both types of samples, a previous food contact (infant formula) as well as the exposure procedure (immersion or article filling) has influenced on the PC degradation.     

Additive migration from various plastics with different processing or properties into test fat HB 307

The migration of the antioxidant n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate from various plastics into the test fat HB 307 was investigated. Plastics from the following classes were included: high-impact polystyrene (HIPS), polypropylene (PP), high- and low-density polyethylene (HDPE and LDPE), and were found to have distinctly different properties--in particular, different densities, melt flow indices and structural characteristics. Each plastic was processed into test specimens such as pressed and extruded sheets, injection-moulded cups, deep-drawn tubs and blown bottles. The migration out of these specimens was investigated under identical test conditions. The results confirm that the amounts of additive migrating from the different classes of plastics into test fat HB 307 in general decrease in the order LDPE greater than HDPE greater than PP greater than HIPS. Moreover, it seems to be of great importance that the respective amounts of additive migrating from the injection-moulded cups, deep-drawn tubs and blown bottles into test fat were significantly lower in all cases than those from the corresponding pressed or extruded sheets. Presumably, this effect is mainly caused by orientation of the polymer molecules in the injection-moulded, deep-drawn or blown products. It is concluded that the migration of the antioxidant decreases with increasing density of the polymer and that the melt flow index (molecular weight) has hardly any influence. Migration from HIPS into fat increases with the content of impact modifier. In the case of the polyethylenes, the influence of processing on the migration rate decreases with decreasing density of the polymer.     

Identification and quantification of the migration of chemicals from plastic baby bottles used as substitutes for polycarbonate

The results of a study on the analytical identification and quantification of migration of chemicals from plastics baby bottles found in the European Union market made of materials that are now present as substitutes for polycarbonate (PC) are reported. A total of 449 baby bottles with a focus on first age or sets of bottles were purchased from 26 European Union countries, Canada, Switzerland and the USA. From this collection, which contained several duplicates, a total of 277 baby bottles were analysed. The materials included different types of plastic such as PC, polyamide (PA), polyethersulphone (PES), polypropylene (PP), but also silicone, and from the United States a co-polyester marketed under the trade name Tritan?. The bottles were subjected to the conventional migration test for hot fill conditions, i.e. 2?h at 70°C. The simulant used was that specified in European Union legislation (2007/19/EC) for milk, i.e. 50% ethanol. In a first phase 1, migration was conducted since the scope of this investigation was a screening rather than a true compliance testing check. Second and third migrations were performed on selected articles when migrated substances exceeded limits specified in the legislation. In order to verify some materials, a portion of the bottle was cut to run an FT-IR fingerprint to confirm the nature of the polymer. The migration solutions in general showed a low release of substances. Results showed that bottles made of PP and silicones showed a greater number of substances in the migration solutions and in greater quantity. Chemicals from PP included alkanes, which could be found in >65% of the bottles at levels up to 3500?µg?kg^?1; and benzene derivatives in 17% of the baby bottles and found at levels up to 113?µg?kg^?1. Some substances were found on a regular basis such as plasticisers, esters and antioxidants (e.g. tris(2,4-di-tert-butylphenyl)phosphate, known as Irgafos 168. Some substances found were not included in the Community positive list, which means that those should not be found even in the first migration. Such substances included 2,6-di-isopropylnaphthalene (DIPN), found in 4% of the bottles at levels up to 25?µg?kg^?1, 2,4-di-tert-butyl phenol (in 90% of the bottles at levels up 400?µg?kg^?1). Moreover, bisphenol A (BPA) was detected and quantified in baby bottles made of PA, but limited to one brand and model specific (but labelled BPA free). Results for baby bottles made of silicone also indicated the presence of components, e.g. potentially coming from inks (benzophenone, diisopropyl naphtahalene – DIPN, which could come for example from the presence of instruction leaflets in the bottles). In the case of silicone, phthalates were also found in relevant concentrations, with levels for DiBP and DBP from the first migration test of 50–150?µg?kg^?1 and DEHP at levels 25–50?µg?kg^?1.     

Interaction of packaging materials and vegetable oils: oil stability

The effects of different plastic films (polyethyleneterephthalate, polyvinylchloride, polypropylene and polystyrene) on the stability of olive, sunflower and palm oils were studied at 24 and 37°C during 60 days of storage. The changes in peroxide value (PV) and thiobarbituric acid value (TBA) were significantly higher (p≤0.05) in the plastic bottles than in glass. Our study indicates that the plastic permeability has played a major role in oil stability. However, both butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) were found to leach out from plastics films into vegetable oils during storage. The rate of oxidation was not reduced by antioxidant migration from plastic films to oils. Natural antioxidant (vitamin E) retarded the oxidation rate, and this was dependent on its concentration in oils examined. The results showed that the ranking of stability of oil samples is PVC≥PET>PP≥PS. Further, the stability was dependent on the type of oil. Palm oil exibited high stability properties while the highest oxidation rate was observed in sunflower oil. In addition, increasing storage temperature accelerated the oxidation and limited the stability of vegetable oils.     

聚碳酸酯饮水桶中掺杂再生料的判定方法研究

目的 建立聚碳酸酯饮水桶中掺杂再生料的判定方法。 方法 将聚碳酸酯(PC)新料双螺杆反复熔融挤出成型,模拟食品接触用PC的循环再生过程,通过对PC新料和模拟再生料的对比分析,寻找到区分PC新料和PC再生料的关键成分酚类物质及酚类物质快速可靠的检测方法紫外可见光谱法和气相色谱-质谱联用法。最后在PC新料中掺杂不同含量的PC再生料,验证建立方法的可靠性。结果 紫外光谱筛查结合气相色谱-质谱联用的分析检测系统可以对掺杂再生料比例低至20 %的样品进行判定。结论 本文建立的紫外光谱筛查结合气相色谱/质谱联用确证的方法能够实现聚碳酸酯再生料的快速、准确的测定。     

Limonene and Myrcene Sorption into Refillable Polyethylene Terephtalate Bottles, and Washing Effects on Removal of Sorbed Compounds

The sorption of two orange volatile compounds, myrcene and limonene, into refillable polyethylene terephtalate bottles, different types of polyethylene terephtalate strips, and polycarbonate strips, was studied. The bottles were washed with sodium hydroxide solutions and remaining aromas in the plastic were analyzed. Sorption continued during the 12 wks storage, but the major part was sorbed during the first week. Bottles stored at 25°C absorbed considerably more myrcene and limonene than bottles stored at 4°C. A simulated industrial washing procedure removed small amounts of the aromas but 50–80% remained in the packaging material. Polycarbonate absorbed flavors to a much larger extent than did polyethylene terephtalate.     

Development and application of a non-targeted extraction method for the analysis of migrating compounds from plastic baby bottles by GC-MS

In 2011, the European Union prohibited the production of polycarbonate (PC) baby bottles due to the toxic effects of the PC monomer bisphenol-A. Therefore, baby bottles made of alternative materials, e.g. polypropylene (PP) or polyethersulphone (PES), are currently marketed. The principal aim of the study was the identification of major compounds migrating from baby bottles using a liquid–liquid extraction followed by GC/MS analysis. A 50% EtOH in water solution was selected as a simulant for milk. After sterilisation of the bottle, three migration experiments were performed during 2 h at 70°C. A non-targeted liquid–liquid extraction with ethyl acetate–n-hexane (1:1) was performed on the simulant samples. Identification of migrants from 24 baby bottles was done using commercially available WILEY and NIST mass spectra libraries. Differences in the migrating compounds and their intensities were observed between the different types of plastics, but also between the same polymer from a different producer. Differences in the migration patterns were perceived as well between the sterilisation and the migrations and within the different migrations. Silicone, Tritan? and PP exhibited a wide variety of migrating compounds, whereas PES and polyamide (PA) showed a lower amount of migrants, though sometimes in relatively large concentrations (azacyclotridecan-2-one up to 250 µg kg^?1). Alkanes (especially in PP bottles), phthalates (dibutylphthalate in one PP bottle (±40 µg kg^?1) and one silicone bottle (±25 µg kg^?1); diisobutylphthalate in one PP (±10 µg kg^?1), silicone (up to ±80 µg kg^?1); and Tritan? bottle (±30 µg kg^?1)), antioxidants (Irgafos 168, degradation products of Irganox 1010 and Irganox 1076), etc. were detected for PP, silicone and Tritan? bottles. Although the concentrations were relatively low, some compounds not authorised by European Union Regulation No. 10/2011, such as 2,4-di-tert-butylphenol (10–100 µg kg^?1) or 2-butoxyethyl acetate (about 300 µg kg^?1) were detected. Migrating chemicals were identified as confirmed (using a standard) or as tentative (further confirmation required).     

Migration of bisphenol A from plastic baby bottles,baby bottle liners and reusable polycarbonate drinking bottles

Human exposure to bisphenol A (BPA) has recently received special attention. It has been shown that exposure to BPA may occur through the consumption of beverages or foods that have been in contact with polycarbonate (PC) plastic containers or epoxy resins in food packaging. A BPA migration study was conducted using a variety of plastic containers, including polycarbonate baby bottles, non-PC baby bottles, baby bottle liners, and reusable PC drinking bottles. Water was used to simulate migration into aqueous and acidic foods; 10% ethanol solution to simulate migration to low- and high-alcoholic foods; and 50% ethanol solution to simulate migration to fatty foods. By combining solid-phase extraction, BPA derivatization and analysis by GC-EI/MS/MS, a very low detection limit at the ng l^?1 level was obtained. Migration of BPA at 40°C ranged from 0.11 µg l^?1 in water incubated for 8 h to 2.39 µg l^?1 in 50% ethanol incubated for 240 h. Residual BPA leaching from PC bottles increased with temperature and incubation time. In comparison with the migration observed from PC bottles, non-PC baby bottles and baby bottle liners showed only trace levels of BPA. Tests for leachable lead and cadmium were also conducted on glass baby bottles since these represent a potential alternative to plastic bottles. No detectable lead or cadmium was found to leach from the glass. This study indicated that non-PC plastic baby bottles, baby bottle liners and glass baby bottles might be good alternatives for polycarbonate bottles.     

Migration of plasticizers phthalates, bisphenol A and alkylphenols from plastic containers and evaluation of risk

This study investigates the potential migration of plasticisers, plastic components and additives from several plastic water bottles. Compounds studied were phthalates (dimethyl phthalate, di-n-butyl phthalate, benzylbutyl phthalate, bis(2-ethylhexyl) phthalate), bis(2-ethylhexyl) adipate, octylphenol, 4-nonylphenol and bisphenol A. Polycarbonate (PC), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET) and polystyrene (PS) plastics used in the water bottling sector were tested using three kinds of total or specific migration tests: (1) standard method UNE-EN ISO 177; (2) ultrasonic forced extraction; and (3) standard method UNE-EN 13130-1. In addition, bottled waters contained in different plastic materials were analysed to determine the potential migration of target compounds in real conditions. In all cases, samples were solid-phase extracted using Oasis HLB 200 mg cartridges and analysed using GC-MS in scan-acquisition mode. Bisphenol A and 4-nonylphenol were detected in incubated samples, indicating that migration from food plastics can occur at the experimental conditions tested. The total daily intake was calculated according to the levels detected in bottled water and the assessment of the consumers' risk was evaluated taking into consideration toxicological and legislative values.     

Migration of plasticizersphthalates,bisphenol A and alkylphenols from plastic containers and evaluation of risk

This study investigates the potential migration of plasticisers, plastic components and additives from several plastic water bottles. Compounds studied were phthalates (dimethyl phthalate, di-n-butyl phthalate, benzylbutyl phthalate, bis(2-ethylhexyl) phthalate), bis(2-ethylhexyl) adipate, octylphenol, 4-nonylphenol and bisphenol A. Polycarbonate (PC), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET) and polystyrene (PS) plastics used in the water bottling sector were tested using three kinds of total or specific migration tests: (1) standard method UNE-EN ISO 177; (2) ultrasonic forced extraction; and (3) standard method UNE-EN 13130 UNE-EN 13130. 2005. Materials and articles in contact with foodstuffs – plastics substances subject to limitation. Part 1: guide to test methods for the specific migration of substances from plastics to foods and food stimulants and the determination of substances in plastics and the selection of conditions of exposure to food simulants.  [Google Scholar]-1. In addition, bottled waters contained in different plastic materials were analysed to determine the potential migration of target compounds in real conditions. In all cases, samples were solid-phase extracted using Oasis HLB 200?mg cartridges and analysed using GC-MS in scan-acquisition mode. Bisphenol A and 4-nonylphenol were detected in incubated samples, indicating that migration from food plastics can occur at the experimental conditions tested. The total daily intake was calculated according to the levels detected in bottled water and the assessment of the consumers’ risk was evaluated taking into consideration toxicological and legislative values.     

Comparison of the recyclability of flame-retarded plastics

Mechanical recycling of plastics from waste from electrical and electronical equipment (WEEE) is increasingly expected by regulators and demanded by original equipment manufacturers (CEMs); however, mechanical recycling is generally recognized to be the most economically costly and technically challenging method of recovering WEEE plastics. With 12% of WEEE plastics requiring the use of flame-retardants in order to ensure appropriate levels of consumer fire safety, there is a distinct need for data from comparative tests on recyclability of various flame-retarded plastics. Ten commercially available flame-retarded plastic grades commonly used in electronic equipment (eight "halogen-free" grades and two grades containing brominated flame-retardants (BFRs)) were subjected to two different recycling scenarios. A standard recycling scenario was carried out by repeatedly extruding the materials and an accelerated hydrolysis scenario was carried out to study the influence of humidity from air during use on the process. Both, virgin and recycled materials were tested for a potential formation of polybrominated dibenzodioxins/furans (PBDD/Fs), their mechanical properties were assessed and the fire safety rating was determined. Results indicate that none of the tested materials showed a potential to form the PBDD/Fs regulated by the German Chemicals Banning Ordinance. The halogen-free plastic grades showed a significant deterioration of mechanical properties after recycling, whereas those plastics containing BFRs were able to pass all test criteria, thus maintaining their original properties. With respect to the fire safety rating, none of the eight tested halogen-free plastic grades could maintain their fire safety rating after five recycling loops, whereas both BFR plastics continued to achieve their fire safety ratings. Therefore the tested BFR containing plastic materials showed superior recycling properties compared to the tested halogen-free plastic grades with respect to all investigated parameters.     

Safe storage of maize in alternative hermetic containers

Purdue Improved Crop Storage (PICS) bags have been developed and extended as a way to address grain storage issues faced by smallholder farmers in developing nations. A hermetic technology, PICS bags reduce insect damage to grain significantly while maintaining its quality for many months or longer. Farmers with varying and often small volumes of grain at harvest, may still benefit from alternatives to PICS bags for storing their grain. We evaluated plastic bottles, which may be hermetically sealed, for storing maize grain. Clean maize grain was stored for eight months in sealed and unsealed plastic bottles with half of these bottles being infested by maize weevil (Sitophilus zemais, Motschulsky). Oxygen levels in the bottles were monitored throughout the trial and grain was assessed for moisture content, insect damage, germination rate and insect population size when the study was terminated. Sealed bottles preserved grain quality significantly better than unsealed, infested bottles and as well as non-infested unsealed containers. Plastic soda bottles can be used as hermetic containers for safely storing grain.     

Sensory characterization of polyester-based bottle material inertness using threshold odour number determination

Refillable polyester bottles, for example polyethylene terephthalate (PET) bottles, are known to interact with chemicals. Aroma compounds from a product can be absorbed by the bottle material, remain after washing and remigrate when the bottle is reused, resulting in off-flavour of the new product. A certified reference material has recently been approved with which the chemical and sensory inertness of refillable bottle materials can be tested. In this study a sensory method aimed at characterizing the sensory inertness properties of the reference bottle material was developed. A use-reuse situation was simulated by storing bottle wall strips in a solution of four odour-active compounds (the loading phase) and, after cleaning, immersing them in water (the remigration phase). The remigration water was analysed with both a sensory method, i.e. determination of the threshold odour number, and chemically using gas chromatography-mass spectrometry (GC-MS). Additionally, another PET and a polyethylene naphthalate (PEN) bottle material were also tested. The sensory threshold determination method could differentiate between the PEN materials and the PET materials. Results from chemical analysis showed that the inertness properties of the PET materials were very similar. The PEN material exhibited significantly superior inertness properties, with only 3-24% of the aroma transfer properties of PET.     

Overall migration from commercial coextruded food packaging multilayer films and plastics containers into official EU food simulants

The overall migration from a wide range of commercial five-layer coextruded packaging films into aqueous food simulants (distilled water, 3% aqueous acetic acid) and alternative fatty food simulant (iso-octane) was studied. The overall migration from commercial plastics cups (PS, HIPS, and PP) used for ice-cream or yogurt packaging into distilled water and 3% aqueous acetic acid was also studied. Test conditions for packaging material/food simulant contact and method of overall migration analysis were according to the EU directives and CEN-standards. The results showed that for all tested five-layer films and plastics (PS, HIPS, and PP) cups values of overall migration into aqueous simulants (0.11-0.79 mg/dm², 2.3-15.9 mg/l) and (<0.10-0.41 mg/dm², <0.80-3.1 mg/l) were significantly lower than the upper limit (10 mg/dm²) for overall migration from plastic packaging materials and articles into food and food simulants set by the EU Directive 90/128/EEC and their revisions. The overall migration values from five-layer materials into iso-octane were significantly higher (0.94-8.23 mg/dm², 18.8-164.7 mg/l) than the above values but are still lower than the upper limit for overall migration. Global migration values of five-layer films into aqueous food simulants seems to be independent of material thickness. In contrast, overall migration into iso-octane increases with film thickness.     

Migration of 2-butoxyethyl acetate from polycarbonate infant feeding bottles

An enforcement campaign was carried out to assess the migration of 2-butoxyethyl acetate (2-BEA) from polycarbonate infant feeding bottles intended for repeated use. Migration was measured by three successive migration tests into two of the European Union official food simulants: distilled water and 3% acetic acid testing at 40°C for 10 days. The Danish Veterinary and Food Administration (DVFA) has assessed that a migration above 0.33 mg for 2-BEA and a group of eight related substances kg^-1 foodstuff from plastics articles used exclusively for infants is unacceptable. Migration of 2-BEA was found from eight of 12 bottles. However, migration above the target value of 0.33 mg kg^-1 was not observed in the third decisive test from any of the 12 different brands of polycarbonate feeding bottles. A migration of between 0.05 and 0.26 mg kg^-1 from seven of 12 bottles was measured to 3% acetic acid in the third test, whereas no migration to distilled water was observed in the third test. The average recovery of 2-BEA after the 10-day exposure at the target value of 0.33 mg kg^-1 was 77% into distilled water and 36% into 3% acetic acid. The limited recovery was understandable as 2-BEA was partly hydrolysed in the aqueous food simulants and 2-butoxyethanol, a hydrolysis product and one of the related substances was identified. Quantification was carried out using gas chromatography after liquid/liquid extraction of the food simulant.     

Migration of bisphenol A from polycarbonate baby bottles under real use conditions

Migration of the potential endocrine disrupter, bisphenol A (BPA), from 31 polycarbonate (PC) baby bottles into aqueous food simulants was studied under real repetitive use, using a sensitive and fully validated liquid chromatographic method with fluorescence detection. Confirmation of the presence of BPA was performed by liquid chromatography-mass spectrometry (LC-MS). The effects of cleaning in a dishwasher or with a brush, sterilization with boiling water and the temperature of migration were examined. It was shown that temperature was the crucial factor for the migration of BPA from the plastic bottles to water. All samples released BPA in the concentration range 2.4-14.3 µg kg^-1 when filled with boiled water and left at ambient temperature for 45 min. The decrease of BPA release in the sterilization water and in the food simulant over 12 cycles of use indicated that the hypothesis of polymer degradation in water is dubious. Estimated infantile dietary exposure, regarding the use of PC baby bottles, ranged between 0.2 and 2.2 µg kg^-1 bw day^-1, which is below the Tolerable Daily Intake of 50 µg kg^-1 bw recently established by EFSA.     

PET瓶在热灌装饮料中的应用

通过PET的分子结构、物理／化学特性来说明影响PET瓶品质的物理、化学因素；通过PET瓶的生产工艺流程及热灌装PET的吹瓶方法／过程、及影响因素来说明PET瓶品质问题的产生原因及其解决方法；通过PET瓶在热灌装线的使用过程来说明影响PET热灌装饮料包装品质的因素及其解决方法；从而为PET瓶在热灌装线的使用提供了较有借鉴意义的一手资料。