Migration of bisphenol A from can coatings—effects of damage, storage conditions and heating

Bisphenol A (BPA) is an important monomer used in the manufacture of epoxy resins for internal food can linings. Experiments were conducted to investigate the effects of different storage conditions and can damage on the migration of BPA to foods. These experiments were conducted in a systematic fashion by filling empty epoxyphenolic coated cans with four foods: soup, minced beef, evaporated milk and carrots and a food simulant (10% ethanol). Filled cans of each food type or simulant were then sealed and processed using appropriate conditions, before storage at three different temperatures: 5°C, 20°C and 40°C. For each of the storage regimes, 50% of the cans were dented to establish if this would lead to increased BPA migration. Cans were removed from these stocks at intervals of 1, 3 and 9 months storage at 5°C and 20°C or 10 days, 1 and 3 months at 40°C. Some initial problems of heterogeneity between samples was overcome by determining the amount of BPA in food as well as in the can lining. It was found that 80-100% of the total BPA present in the coating had migrated to foods directly after can processing by pilot plant filling with food or simulant, sealing and sterilization. This level was not changed by extended storage (up to 9 months) or can damage, indicating most migration was occurring during the can processing step. There was no noticeable difference, in this respect, between the different foods or the food simulant. Analysis of control samples (foods fortified with ∼0.1 mg kg^-1 BPA and contained in Schott bottles) showed that BPA was stable under both processing and storage. Experiments were also conducted to investigate the potential effects, on the migration of BPA from can coatings, of cooking or heating foods in the can prior to consumption. Food cans were purchased and the food either cooked or heated in the can. BPA was analysed prior to and after the heating/cooking process. It was concluded from the results that there were no appreciable differences in the BPA level before and after cooking or heating.     

Cause of bisphenol A migration from cans for drinks and assessment of improved cans

In the previous investigation, we found that some cans for coffee and black tea drinks released large amounts of bisphenol A (BPA) into their contents. Equivalent cans were obtained and the cause of BPA migration was investigated. Equivalent cans A, B and D contained high levels of BPA in the side seam, in the bottom, and in the bottom and the side seam, respectively, while can C contained some level of BPA in the body, which has a large area, therefore, all of them contained high amounts of BPA in their coatings. In the migration test, there was no BPA migration from the cans into water at 60 and 95 degrees C for 30 min, into 20% ethanol at 60 degrees C for 30 min, or into n-heptane at 25 degrees C for 60 min. However, at 120 degrees C for 30 min, equivalent cans released 35-124 ng/mL BPA into the water. The total migration was similar to the total residues of BPA in the can coating and was close to the total amount of BPA in the drinks. Thus, BPA migration from the can coating requires heating to more than 105 degrees C, which is the glass transition temperature of the epoxy resin. Improved cans which contained less than 1/10 as much BPA as the equivalent cans showed very low migration levels, i.e., 3-6 ng/mL.     

Effect of sterilisation and storage conditions on the migration of bisphenol A from tinplate cans of the Lebanese market

The use of bisphenol A (BPA) in lacquer coating of food cans has been restricted by different authorities in many countries, such as in Europe. However, such regulation does not exist in many other countries including Lebanon. Due to the lack of data on the quality of Lebanese can production; this study investigates the migration of BPA from two types of tinplate cans manufactured in Lebanon, before and after sterilisation. Cans were analysed under different storage conditions (time and temperature) and filled with an aqueous simulant. The determination of BPA was carried out using UPLC with fluorescence detection, and further confirmed by MS detection. After sterilisation BPA levels drastically increased from an average of 0.15 to 109 µg/kg, giving a BPA migration around 10.5 µg/dm² for both types of cans. Storage temperature and time had no significant influence on BPA levels in sterilised cans (p-value > 0.05); however, these factors significantly affected BPA levels in non-sterilised cans.     

Migration of bisphenol A from polycarbonate baby bottles purchased in the Spanish market by liquid chromatography and fluorescence detection

During the last decade the safety of bisphenol A (BPA) monomer in polycarbonate baby bottles has drawn the attention of both the public and the scientific community. This paper presents the results of BPA migration from polycarbonate baby bottles bought in the Spanish market, into simulant B (3% acetic acid), 50% ethanol and into real food (reconstituted infant formula). Furthermore, it was also the objective of this study to assess the suitability of 50% ethanol as a simulant for infant formula. BPA was analysed by a multi-analyte liquid chromatography method with fluorescence detection and mass spectrometry confirmation. The method was in-house validated and accredited by the national accreditation body. The validation results for this analyte in the previous mentioned matrices were: LOD = 0.004-0.007 mg kg(-1); LOQ (validated) = 0.03 mg kg(-1); RSD% = 3.4-5.8; and recovery = 106.6-118.2%. A collection of 72 different baby bottle samples from 12 different brands were analysed. Baby bottle material was identified by FTIR. The migration test conditions used were those recommended for baby bottles in the Guidelines on testing conditions for articles in contact with foodstuffs (with a focus on kitchenware), prepared by the European network of laboratories for food-contact materials. In most of the migration assays the results were below the LOD. In four of the commercial brands there was detectable migration into the simulant 50% ethanol and BPA was detected in only two samples of infant formula (0.01 mg kg(-1)). Migration results obtained were in compliance with European Union regulations.     

Determination of bisphenol A in canned fish by sol–gel immunoaffinity chromatography,HPLC and fluorescence detection

The paper presents a highly selective analysis method for the determination of bisphenol A (BPA) in canned fish. The procedure consists of sample clean-up by sol–gel immunoaffinity chromatography followed by high performance liquid chromatography and fluorescence detection. BPA concentrations were determined in nineteen tuna, sardine and mackerel cans by analysing the solid and the liquid parts of the contents separately. In different tested matrices limits of detection (S/N=3) ranged from 0.2 ng/g (sardines) to 1.8 ng/ml (oil) and limits of quantification (S/N=6) from 0.4 ng/g to 3.8 ng/ml, respectively. In the solid part (fish) very low BPA levels (2–4 ng/g) were found in mackerels, the highest level (59 ng/g) in tuna. In oil significantly higher BPA concentrations were found than in brine. In all samples BPA concentrations were significantly lower than the Specific Migration Level of 0.6 mg/kg for BPA migration into food established by the EU Commission in 2004.     

Bisphenol A migration from cans containing coffee and caffeine

This study was conducted to reconfirm the possibility and level of bisphenol A (BPA) migration from cans containing coffee and test the relationship between caffeine concentration and BPA migration from the can coating. BPA migration from cans containing decaffeinated and non-decaffeinated instant coffee averaged 66.2 and 84.0 ng ml -1 , respectively. In our study, the possibility of BPA migration from cans containing coffee after processing was found. In addition, the more caffeine content in the water solution of caffeine increased, the more BPA migration grew. This means that caffeine can have an effect on BPA migration from the can coating.     

Factors influencing the migration of bisphenol A from cans

The objective of this study was to determine whether there is a relationship between bisphenol A (BPA) migration from metal cans and container contents (glucose, sodium chloride, and vegetable oil), heating time, and/or temperature. Cans containing 5 to 20% glucose solution, 1 to 10% sodium chloride solution, and vegetable oils (corn, olive, and soybean oil) were heated at 121 degrees C for 30 min. Water samples were heated at 105 degrees C for 30 min and at 121 degrees C for 15, 30, and 60 min, respectively. In the test involving water samples, it was found that temperature's effect on BPA migration from cans can be more extensive than that of heating time. When cans were heated at 121 degrees C, the presence of 1 to 10% sodium chloride or vegetable oils greatly increased the migration of BPA from the cans. Moreover, the presence of 5 to 20% glucose in cans heated to 121 degrees C resulted in increased BPA migration relative to that for water controls.     

Migration of iron,lead, cadmium and tin from tinplate-coated cans into chickpeas

Migration studies of trace metals were carried out on coated chickpea cans marketed in Lebanon. Four elements – iron (Fe), tin (Sn), lead (Pb) and cadmium (Cd) – were analysed by atomic absorption spectrometry (AAS) after microwave digestion. Over 3 months, three different storage temperatures (5°C, room temperature and 40°C) were tested. In all cases, the migration of Fe reached a plateau after around 50 days of storage, while the migration of Pb was slow till 50 days, then it increased rapidly. Cd and Sn levels did not increase. Moreover, no effect of temperature was observed in the case of Fe, whereas Pb levels showed slower migration in cans stored at 5°C. Comparing cans from different chickpea brands (Lebanese and foreign) showed that the characteristics of the container have an effect on metal release.     

Bisphenol A (BPA) and its source in foods in Japanese markets

The determination of bisphenol A (BPA) and/or bisphenol A diglycidyl ether (BADGE) in foods sold in Japanese markets and in water leached from six epoxy resin cans with similar diameters was carried out using high-performance liquid chromatography (HPLC) with electrochemical detection (LC/ECD), LC-mass spectrometric detection (LC/MS) and LC-tandem mass spectrometric detection (LC/MS/MS). BPA concentrations were 0-842 ng g^-1 for 48 canned foods, 0-14 ng g^-1 for 23 foods in plastic containers, and 0-1 ng g^-1 for 16 foods in paper containers. No BADGE was detected in three canned foods. There was no difference in leaching concentrations of BPA into glycine buffers at pHs 8 and 11, and water. The amounts of BPA leached into water from six epoxy resin cans held at 121°C for 20 min were almost the same as the cans' contents and were much higher than the amounts leached from cans held at or below 80°C for 60 min. The amount leached depended on the type of can, but not on the amount of BADGE leached from the cans. Considerably more BPA than BADGE leached to water from six cans. Two cans whose contents had high concentrations of BPA showed no BADGE leaching even at 121°C, suggesting the different kinds of epoxy resin can linings from others. The results imply that the main source of human exposure to BPA is food from cans with linings that contain high percentages of BPA as an additive or an unforeseen contaminant.     

Migration of melamine from can coatings cross-linked with melamine-based resins,into food simulants and foods

Resins based on melamine-formaldehyde and related analogues such as methylolated melamine are used to cross-link coatings used inside food cans and on the metal closures of glass jars. Thirteen commercially coated cans and closures representing 80% of the European market were tested using simulants under realistic industrial heat-processing conditions for canned and jarred foods. The food simulants and the retort conditions used were 3% acetic acid for 1?h at 100°C and 10% ethanol for 1?h at 130°C. The highest migration level seen for melamine into simulant was 332?µg?kg^?1. There was no detectable migration of the melamine analogues cyanuric acid (<1?µg?kg^?1) or ammelide (<5?µg?kg^?1) from any sample. Twelve of the thirteen samples released no detectable ammeline (<5?µg?kg^?1) but the coating giving the highest release of melamine did also release ammeline at 8?µg?kg^?1 with the higher of the two process temperatures used. Migration experiments into food simulant and foods themselves were then conducted using two experimental coatings made using amino-based cross-linking resins. Coated metal panels were exposed to the food simulant 10% (v/v) aqueous ethanol and to three foodstuffs under a range of time and temperature conditions both in the laboratory and in a commercial food canning facility using proprietary time and temperature conditions. The highest migration into a food was 152?µg?kg^?1 from the first coating processed for a long time at a moderate sterilisation temperature. The highest migration into simulant was also from this coating at 220?µg?kg^?1 when processed at 134°C for 60?min, dropping to 190?µg?kg^?1 when processed at 123°C for 70?min. Migration from the second coating was quite uniformly two to three times lower under all tests. These migration results were significantly higher than the levels of melamine extractable using 95% ethanol at room temperature. The experiments show that commercial canning and retorting can be mimicked in an acceptable way using laboratory tests with an autoclave or a simple pressure cooker. The results overall show there is hydrolytic degradation of the melamine cross-linked resins to release additional melamine. There is a strong influence of the temperature of heat treatment applied with foods or simulants but only a minor influence of time of heating and only a minor influence, if any, of food/simulant acidity.     

Bisphenol A in canned foods in New Zealand: an exposure assessment.

Exposure to bisphenol A (BPA) from the consumption of canned and bottled food has been determined for New Zealand adults. Eighty different canned foods purchased from retail outlets in Christchurch, New Zealand, between November 2003 and February 2004 were analysed for BPA concentration by gas chromatography/mass spectrometry. BPA was detected in all foods analysed except for soft drinks. Concentrations ranged from < 10 to 29 microg kg(-1), except for individual samples of tuna, corned beef and coconut cream, which were 109, 98 and 191 microg kg(-1) , respectively. The limit of quantitation was <10 microg kg(-1) for foods of low fat content (< 1%) and <20 microg kg(-1) for foods containing >1% fat. Mean concentration data were combined with 24-h dietary recall information for 4399 individual consumers. Mean and maximum exposures were 0.008 and 0.29 microg kg(-1) bw day(-1), respectively, well below the temporary tolerable daily intake of 10 microg kg(-1) bw day(-1) given by the European Commission in 2002. The results of the present survey suggest that the levels of BPA identified in canned foods are unlikely to be of concern to adult health, and there is no reason for consumers to change their consumption patterns as a result of these findings. When the concentration data found in the current survey are applied to an oestrogenicity model for an adult male, the contribution of BPA to the total oestrogenicity from 16 food components is 7%. The impact of this level of oestrogenicity remains unclear.     

Comparison of migration from polyethersulphone and polycarbonate baby bottles

This work presents two analytical methods developed for measuring three components of polyethersulphone (PES) and applying them to the migration testing of 30 baby bottles made of PES. The study also provides migration results under the same conditions for bisphenol A (BPA) from 40 polycarbonate baby bottles using a well-established method adapted to low concentrations. For PES bottles, migration of diphenyl sulphone (DPS), 4,4'-dichlorodiphenyl sulphone (DCPS) and 4,4'-dihydroxydiphenyl sulphone (DHPS; also known as bisphenol S) was carried out using two different analytical methods with detection limits of 0.1-0.3 μg/kg, and, therefore, much below their respective European Commission Directive 2002/72/EC legislative migration limits of 50-3000 μg/kg, respectively. In parallel, 40 bottles made of polycarbonate were analysed for the migration of BPA using a method validated at EU level and modified to give a lower detection limit of 0.1 μg/kg. Migration tests were conducted into the simulant for milk 50% EtOH (as per Commission Regulation No. 321/2011 of 1 April 2011) according to the test conditions from the guidelines on test conditions for articles in contact with foodstuffs (with a focus on kitchenware) prepared by the EU Reference Laboratory and its network of National Reference Laboratories. None of the 30 bottles made of PES released any detectable amounts of DCPS or DHPS and only two bottles released a very low amount of DPS of ~1 μg/kg in the milk food simulant compared to a regulatory limit of 3000 μg/kg. For PC bottles, 32 bottles of 40 (80%) did not release BPA above the LOD of 0.1 μg/kg (in any of the three migration tests performed on each bottle). The other 20% of bottles exhibited only very minor migration, where the highest level in the first migration test was 1.83 μg/kg and most bottles did not release detectable BPA in the second and third test. Only one bottle, with a migration level of 1.08 μg/kg, in the first test still showed a detectable level in the last migration test (i.e. 0.42 μg/kg). It is important to note that the legal limit (European Commission Directive 2002/72/EC) was still 600 μg/kg for polycarbonate bottles at the time of purchase, preceding the precautionary ban taking effect from 1 June 2011 (Commission Directive 2011/8/EU; Commission Regulation No. 321/2011). This confirms that the likelihood of migration of BPA is very low and remains at very minute amounts. The results also suggest the absence of release from PES bottles based on the set of bottles investigated.     

Survey of bisphenol a diglycidyl ether (BADGE) in canned foods.

2,2-Bis(4-hydroxyphenyl)propane bis(2,3-epoxypropyl) ether (BADGE) is used in the manufacture of lacquers for coating the inside of food and beverage cans. In June 1996 the EC Scientific Committee for Food temporarily increased the specific migration limit applying to BADGE to 1 mg/kg pending consideration of additional toxicological data. In order to find out if there is migration of BADGE from can coatings into foods, a 'worst case' sampling exercise has been conducted to survey those canned foods where the propensity for migration of BADGE was judged to be highest. The foods surveyed include canned fish in oil, meat and milk and, altogether, BADGE was determined in 181 retail samples. Analysis for BADGE was conducted, in duplicate, by HPLC with fluorescence detection with confirmation of BADGE identity by GC/MS analysis using selected ion monitoring. BADGE was found at levels exceeding 1 mg/kg in seven of the 15 canned anchovy samples and five of the 22 sardine samples purchased during the period September 1995-July 1996. Infrared analysis of the can coatings provided strong evidence that the higher BADGE levels found were associated with use of PVC organosol lacquers, although in some cases cans coated with organosols gave low BADGE results. For canned sardine samples found to contain greater than 0.5 mg/kg BADGE in the total contents, a replicate can was opened and separate analyses performed on the drained fish and the oil. The results clearly showed that BADGE concentrations in the oil were about 20 times higher than in the drained fish. Further samples of canned sardines and anchovies were purchased in June/July 1997 and, in all cases, BADGE levels were found to be below 1 mg/kg. In the other retail canned foods, BADGE was not detectable (DL = 0.02 mg/kg) or detected at concentrations well below the temporary SML of 1 mg/kg.     

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.     

The migration of Irganox 1010 antioxidant from high-density polyethylene and polypropylene into a series of potential fatty-food simulants

Alternatives to highly-volatile ethanol or analytically complex cooking oil were examined as potential fatty-food simulants which would undergo high-temperature exposures to food-packaging polymers in food-packaging evaluation studies. The alternatives consisted of alcohols containing four to eight carbons. As test cases, the migration of Irganox 1010 antioxidant from high-density polyethylene and polypropylene into the higher alcohols was compared to the migration of Irganox 1010 into aqueous ethanol solutions and cooking oil, the US Food and Drug Administration's currently recommended fatty-food simulants. The data obtained showed slightly greater migration of the antioxidant into 95% ethanol than into cooking oil, and slightly less migration into 50% ethanol than into cooking oil. The migration of the antioxidant into the alcohols consisting of four or more carbons was much greater than the migration observed in cooking oil. In many experiments the polymers became depleted of the antioxidant prior to the end of the short, high-temperature exposure period (i.e. 2 h at 250 degrees F) to the higher alcohols. Also, for all experiments run under the same time/temperature/simulant conditions, migration of the antioxidant was greater from polypropylene than from high-density polyethylene. Diffusion coefficients generated for 95% ethanol and corn oil from these data compare closely with data from the literature.     

Migration of bisphenol A from polycarbonate baby bottles purchased in the Spanish market by liquid chromatography and fluorescence detection

During the last decade the safety of bisphenol A (BPA) monomer in polycarbonate baby bottles has drawn the attention of both the public and the scientific community. This paper presents the results of BPA migration from polycarbonate baby bottles bought in the Spanish market, into simulant B (3% acetic acid), 50% ethanol and into real food (reconstituted infant formula). Furthermore, it was also the objective of this study to assess the suitability of 50% ethanol as a simulant for infant formula. BPA was analysed by a multi-analyte liquid chromatography method with fluorescence detection and mass spectrometry confirmation. The method was in-house validated and accredited by the national accreditation body. The validation results for this analyte in the previous mentioned matrices were: LOD?=?0.004–0.007?mg?kg^–1; LOQ (validated)?=?0.03?mg?kg^–1; RSD%?=?3.4–5.8; and recovery?=?106.6–118.2%. A collection of 72 different baby bottle samples from 12 different brands were analysed. Baby bottle material was identified by FTIR. The migration test conditions used were those recommended for baby bottles in the Guidelines on testing conditions for articles in contact with foodstuffs (with a focus on kitchenware), prepared by the European network of laboratories for food-contact materials. In most of the migration assays the results were below the LOD. In four of the commercial brands there was detectable migration into the simulant 50% ethanol and BPA was detected in only two samples of infant formula (0.01?mg?kg^–1). Migration results obtained were in compliance with European Union regulations.     

Comparison of migration from polyethersulphone and polycarbonate baby bottles

This work presents two analytical methods developed for measuring three components of polyethersulphone (PES) and applying them to the migration testing of 30 baby bottles made of PES. The study also provides migration results under the same conditions for bisphenol A (BPA) from 40 polycarbonate baby bottles using a well-established method adapted to low concentrations. For PES bottles, migration of diphenyl sulphone (DPS), 4,4′-dichlorodiphenyl sulphone (DCPS) and 4,4′-dihydroxydiphenyl sulphone (DHPS; also known as bisphenol S) was carried out using two different analytical methods with detection limits of 0.1–0.3?µg/kg, and, therefore, much below their respective European Commission Directive 2002/72/EC legislative migration limits of 50–3000?µg/kg, respectively. In parallel, 40 bottles made of polycarbonate were analysed for the migration of BPA using a method validated at EU level and modified to give a lower detection limit of 0.1?µg/kg. Migration tests were conducted into the simulant for milk 50% EtOH (as per Commission Regulation No. 321/2011 of 1 April 2011) according to the test conditions from the guidelines on test conditions for articles in contact with foodstuffs (with a focus on kitchenware) prepared by the EU Reference Laboratory and its network of National Reference Laboratories. None of the 30 bottles made of PES released any detectable amounts of DCPS or DHPS and only two bottles released a very low amount of DPS of ～1?µg/kg in the milk food simulant compared to a regulatory limit of 3000?µg/kg. For PC bottles, 32 bottles of 40 (80%) did not release BPA above the LOD of 0.1?µg/kg (in any of the three migration tests performed on each bottle). The other 20% of bottles exhibited only very minor migration, where the highest level in the first migration test was 1.83?µg/kg and most bottles did not release detectable BPA in the second and third test. Only one bottle, with a migration level of 1.08?µg/kg, in the first test still showed a detectable level in the last migration test (i.e. 0.42?µg/kg). It is important to note that the legal limit (European Commission Directive 2002/72/EC) was still 600?µg/kg for polycarbonate bottles at the time of purchase, preceding the precautionary ban taking effect from 1 June 2011 (Commission Directive 2011/8/EU; Commission Regulation No. 321/2011). This confirms that the likelihood of migration of BPA is very low and remains at very minute amounts. The results also suggest the absence of release from PES bottles based on the set of bottles investigated.     

Migration of bisphenol A into water from polycarbonate baby bottles during microwave heating

A comprehensive migration database was established for bisphenol A from polycarbonate baby bottles into water during exposure to microwave heating. Eighteen different brands of polycarbonate baby bottles sold in Europe were collected. Initial residual content of bisphenol A and migration after microwave heating were determined. Residual content of bisphenol A in the polycarbonate baby bottles ranged from 1.4 to 35.3 mg kg(-1). Migration of bisphenol A was determined by placing a polycarbonate bottle filled with water in a microwave oven and heating to 100 degrees C; the level of bisphenol A in the water was analysed by GC-MS. The procedure of microwave heating and analysis was repeated twice for the same bottle and, thus, three migration extracts were prepared for each test specimen. Migration of bisphenol A into water ranged from <0.1 to 0.7 microg l(-1). There was no correlation between the amount of residual content of bisphenol A in the bottles and the migration of bisphenol A into water. Furthermore, there was no correlation between the amounts of bisphenol A in consecutive migration extracts. Data show that during three microwave-heating cycles of a baby bottle made from polycarbonate, microwave radiation had no effect on the migration of bisphenol A into water from polycarbonate. All levels found were well below the specific migration limit of 0.6 mg kg(-1) specified for bisphenol A in Commission Directive 2004/19/EC.     

Migration of bisphenol A into water from polycarbonate baby bottles during microwave heating.

A comprehensive migration database was established for bisphenol A from polycarbonate baby bottles into water during exposure to microwave heating. Eighteen different brands of polycarbonate baby bottles sold in Europe were collected. Initial residual content of bisphenol A and migration after microwave heating were determined. Residual content of bisphenol A in the polycarbonate baby bottles ranged from 1.4 to 35.3 mg kg(-1). Migration of bisphenol A was determined by placing a polycarbonate bottle filled with water in a microwave oven and heating to 100 degrees C; the level of bisphenol A in the water was analysed by GC-MS. The procedure of microwave heating and analysis was repeated twice for the same bottle and, thus, three migration extracts were prepared for each test specimen. Migration of bisphenol A into water ranged from <0.1 to 0.7 microg l(-1). There was no correlation between the amount of residual content of bisphenol A in the bottles and the migration of bisphenol A into water. Furthermore, there was no correlation between the amounts of bisphenol A in consecutive migration extracts. Data show that during three microwave-heating cycles of a baby bottle made from polycarbonate, microwave radiation had no effect on the migration of bisphenol A into water from polycarbonate. All levels found were well below the specific migration limit of 0.6 mg kg(-1) specified for bisphenol A in Commission Directive 2004/19/EC.     

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.