Migration of plasticizers from cling‐film

GC-MS Analysis of Phthalates and Di-(2-thylhexyl) Adipate in Canadian Human Milk for Exposure Assessment of Infant Population

BACKGROUND

Although more information has become available on the occurrence of phthalates and di(2-ethylhexyl) adipate (DEHA) in foods including cow's milk, information on their presence in human milk, the important and recommended sole diet for infants up to six months of age, is very limited, especially for DEHA.

OBJECTIVE

To develop a GC-MS method for simultaneous analysis of DEHA and phthalates in human milk samples and generate occurrence data for exposure assessment.

METHOD

Human milk samples were extracted with acetonitrile followed by dispersive solid-phase extraction and GC-MS analysis.

RESULTS

Among the 305 human milk samples collected from the Canadian Maternal-Infant Research on Environmental Chemicals Study, some phthalates (DHxP, BBzP, and DOP) were not detected in any of the samples, while DEHA and the other phthalates (DMP, DEP, DBP, DiBP, and DEHP) were detected at low frequencies with levels from 30.4-237 ng/g in up to 31 of the 305 human milk samples.

CONCLUSIONS

In general, DEHA and phthalates were detected at low frequencies and low levels in the 305 human milk samples.

HIGHLIGHTS

A GC-MS method based on dispersive solid phase extraction was developed for analysis of DEHA and eight phthalates in 305 human milk samples for exposure assessment.

Di-(2-ethylhexyl) adipate in selected total diet food composite samples

Polyvinyl chloride (PVC) food-wrapping films plasticized with di-(2-ethylhexyl) adipate (DEHA) are commonly used by grocery stores in Canada to rewrap meat, poultry, fish, cheese, and other foods. DEHA was assessed as part of the Government of Canada's Chemicals Management Plan. The main source of exposure for most age groups was expected to be food. Although the margin of exposure from food and beverages is considered to be adequately protective, the Government of Canada committed to performing targeted surveys of DEHA in foods and food packaging materials to better define Canadian exposure to DEHA through dietary intake. In order to determine whether more-comprehensive targeted surveys on DEHA in foods should be conducted, 26 food composite samples from the 2011 Canadian total diet study were selected and analyzed for DEHA using a method based on solvent and dispersive solid-phase extraction and gas chromatography-mass spectrometry. These 26 food composites include cheese, meat, poultry, fish, and fast foods, and PVC films were likely used in packaging the individual foods used to make the composites. DEHA was detected in most of the meat, poultry, and fish composite samples, with the highest concentration found in ground beef (11 μg/g), followed by beef steak (9.9 μg/g), freshwater fish (7.8 μg/g), poultry liver pâté (7.4 μg/g), fresh pork (6.9 μg/g), cold cuts and luncheon meats (2.8 μg/g), veal cutlets (2.1 μg/g), roast beef (1.3 μg/g), lamb (1.2 μg/g), and organ meats (0.20 μg/g). Targeted surveys should be conducted to investigate the presence of DEHA in various foods packaged with PVC films in more detail and provide updated occurrence data for accurate human exposure assessment.

Phthalate Esters in Foods: Sources, Occurrence, and Analytical Methods

  Phthalates are a group of diesters of ortho-phthalic acid (dialkyl or alkyl aryl esters of 1,2-benzenedicarboxylic acid). Higher-molecular-weight phthalates, such as di-2-ethylhexyl phthalate (DEHP), are primarily used as plasticizers to soften polyvinyl chloride (PVC) products, while the lower-molecular-weight phthalates, such as diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and butyl benzyl phthalate (BBzP), are widely used as solvents to hold color and scent in various consumer and personal care products. Phthalates have become ubiquitous environmental contaminants due to volatilization and leaching from their widespread applications, and thus contamination of the environment has become another important source for phthalates in foods in addition to migration from packaging materials. Human exposure to phthalates has been an increased concern due to the findings from toxicology studies in animals. DEHP, one of the important and widely used phthalates, is a rodent liver carcinogen. DEHP, DBP, BBzP, and several phthalate metabolites, such as monobutyl phthalate, monobenzyl phthalate, and mono-(2-ethylhexyl) phthalate, are teratogenic in animals. Since foods are the major source of exposure to phthalates, information on levels of phthalates in foods is important for human exposure assessment. The objective of this review is to identify the knowledge gaps for future investigations by reviewing levels of a wide range of phthalates in a variety of foods, such as bottled water, soft drinks, infant formula, human milk, total diet foods, and others, migration of phthalates from various food-packaging materials, and traditional and new methodologies for the determination of phthalates in foods.

Contamination of packaged food by substances migrating from a direct-contact plastic layer: Assessment using a generic quantitative household scale methodology

The contamination risk in 12 packaged foods by substances released from the plastic contact layer has been evaluated using a novel modeling technique, which predicts the migration that accounts for (i) possible variations in the time of contact between foodstuffs and packaging and (ii) uncertainty in physico-chemical parameters used to predict migration. Contamination data, which are subject to variability and uncertainty, are derived through a stochastic resolution of transport equations, which control the migration into food. Distributions of contact times between packaging materials and foodstuffs were reconstructed from the volumes and frequencies of purchases of a given panel of 6422 households, making assumptions about household storage behaviour. The risk of contamination of the packaged foods was estimated for styrene (a monomer found in polystyrene yogurt pots) and 2,6-di-tert-butyl-4-hydroxytoluene (a representative of the widely used phenolic antioxidants). The results are analysed and discussed regarding sensitivity of the model to the set parameters and chosen assumptions.

Plasticizers in Brazilian food-packaging materials acquired on the retail market

Packaging materials intended for direct food contact were acquired on the Brazilian retail market and analysed for their plasticizer content. Analyses were carried out by gas chromatography with flame ionization detection. Di-2-ethyl-hexyl adipate (DEHA), di-2-ethyl-hexyl phthalate (DEHP) and di-iso-decyl phthalate (DIDP) plasticizers were identified in films and closure seals in concentrations ranging from 12 to 19% (w/w), 15 to 44% (w/w) and 10 to 11% (w/w), respectively. Brazilian regulations state that for use with foods with a fat content above 5%, the levels of DEHP and DIDP in the plastic material should be no greater than 3%. The results obtained demonstrate a lack of conformity. It would be advisable to include information on the labels of packaging materials about their restrictions of use in order to advise manufacturers and consumers about their proper usage.

Migration of di-(2-ethylhexylexyl)adipate plasticizer from food-grade polyvinyl chloride film into hard and soft cheeses

Food-grade polyvinyl chloride (PVC) film containing 28.3% di-(2-ethylhexylexyl)adipate (DEHA) plasticizer was used to wrap three different types of cheese (Kefalotyri, Edam, and Feta). Samples were split into two groups and stored at 5+/-0.5 degrees C. One group was analyzed for DEHA content at intervals between 1 and 240 h of contact (kinetic study), and a second group was cut into slices (1.2 mm thick) after 240 h of cheese/PVC contact and was analyzed for DEHA content (penetration study). The DEHA was determined by indirect gas chromatography. Statistically significant differences in migration of DEHA were observed between the cheese types. Migration of DEHA depended on contact time, fat, and moisture contents, and consistency of cheese samples. Equilibrium conditions were approached after approximately 100 h of contact for Edam and 150 h for Kefalotyri cheese. Equilibrium conditions were not reached for Feta cheese, even after 240 h of contact. After 240 h of contact under refrigeration, the migration of DEHA was approximately 345.4 mg/kg (18.9 mg/dm2) for Kefalotyri, 222.5 mg/kg (12.2 mg/dm2) for Edam, and 133.9 mg/kg (7.3 mg/dm2) for Feta. The loss of DEHA from the PVC film into the three cheese types was 37.8, 24.3, and 14.6%, respectively. These values, with the exception of Feta, were higher than the upper limit for global migration from plastic packaging materials into food and food stimulants set by the European Union (EU) (10 mg/dm2 or 60 mg/kg). After 240 h of cheese/film contact, DEHA was detected in the first three slices beneath the cheese surface (3.6 mm total depth) of Edam cheese and in the first two slices (2.4 mm total depth) of Kefalotryi and Feta cheeses. DEHA was not detected in subsequent layers. The effect of cheese rind on migration of DEHA was studied in Edam and Kefalotyri cheeses. The DEHA migration after 240 h into the first 1 mm beneath the surface of Kefalotyri cheese was 22.4 mg/kg, while DEHA was not detected in Edam cheese.

Migration of di-(2-ethylhexyl) phthalate from PVC child articles into saliva and saliva simulant

A simple migration test and a more complicated simulation of children's sucking and biting was used to establish migration of DEHP from PVC child-use articles into saliva and compared to a mimic test. The static migration test of a film containing approximately 30% DEHP with saliva simulant gave the lowest values of DEHP; simple shaking increased the amounts of DEHP from 25 +/- 8 to 499 +/- 153 micrograms/g film. The more complicated arrangements to simulate sucking and biting are not so suitable for standard applications. When comparing the in vitro migration tests with the mimic test the factors were 25 and 29 for the static tests (3 and 6 hours) and 1.4 for the shaking test.

Effect of microwave heating on the migration of dioctyladipate and acetyltributylcitrate plasticizers from food-grade PVC and PVDC/PVC films into olive oil and water

Migration of dioctyladipate (DOA) and acetyltributylcitrate (ATBC) plasticizers from plasticized polyvinylchloride (PVC) and polyvinylidene chloride (PVDC)/PVC (Saran) films into both olive oil and distilled water during microwave heating has been studied. The plasticizer migrating into olive oil and water was determined using an indirect GC method after saponification of the ester-type plasticizer (DOA or ATBC) and subsequent collection of the alcohol component of the ester, namely: 2-ethyl-1-hexanol and 1-butanol, respectively. Migration was dependent on heating time, microwave power setting, the nature of the food simulant and the initial concentration of the plasticizer in the film. Migration of DOA into olive oil reached equilibrium after heating for 10 min at full power (604.6 mg DOA/l). Migration into distilled water was 74.1 mg/l after 8 min of microwave cooking at full power. The amount of ATBC migrating into olive oil reached equilibrium after heating for 10 min at full power (73.9 mg ATBC/l). Migration into distilled water was 4.1 mg/l after heating at full power for 8 min. Control samples containing olive oil gave DOA migration values which were significantly higher than the upper limit for global migration (60 mg/l) set by the European Community. It is proposed that PVC should not be used in direct contact with food in the microwave oven, while Saran may be used with caution in microwave heating and reheating applications, avoiding its direct contact with high fat foodstuffs.

PVC cling film in contact with cheese: health aspects related to global migration and specific migration of DEHA

Following exposure to the food simulant olive oil for 10 days at 5, 20 or 40 degrees C a global migration ranging from 20 to 30 mg/dm2 was detected from a common 'low migration' PVC film plasticized with a mixture of di-(ethylhexyl)adipate (DEHA) and a polymeric plasticizer. In a laboratory experiment samples of cheese of the types most commonly consumed in Denmark were wrapped in this 'low migration' PVC film using a procedure simulating the actual pattern of use in retail shops. After a storage time of 2 h at 5 degrees C the level of DEHA was 45 mg/kg of cheese, which after 10 days increased to 150 mg DEHA per kg of cheese, corresponding to an estimated specific migration of 12 mg DEHA/dm2 of cheese surface. Based on statistics on dietary habits it is concluded that the retail packaging of small portions of cheese even in a 'low migration' PVC cling film may lead to consumer intakes of DEHA close to or above the tolerable daily intake of 0.3 mg/kg body weight as defined by the EEC Scientific Committee for Food. Furthermore, it is stressed that measurements of global migration followed by uncritical use of reduction factors may result in erroneous evaluation of the suitability of DEHA-plasticized cling film for the packaging of fatty foods.

The occurrence of phthalate ester and di-2-ethylhexyl adipate plasticizers in Canadian packaging and food sampled in 1985-1989: a survey

Selected foods (260 samples) packaged in materials with the potential to contribute plasticizers to the food, and available food composites (98 samples) obtained from the Canadian Health Protection Branch Total Diet Program, were analysed for phthalate plasticizers and di-2-ethylhexyl adipate (DEHA). The available contacting packaging was also analysed for plasticizers. The results show DEHA in food-contacting film and as a migrant in store-wrapped meat, poultry, fish, cheese and ready-to-eat foods at levels as high as 310 micrograms/g (cheese). DEHA levels in unheated film-wrapped ready-to-eat foods were increased by heating. The di-2-ethylhexyl, dibutyl, butylbenzyl and diethyl phthalate esters (DEHP, DBP, BBP and DEP, respectively) were also found in both the packaging and the contacted foods. Low levels of DEHP (0.065 micrograms/g, average in beverages and 0.29 micrograms/g, average in foods) associated with the use of DEHP-plasticized cap or lid seals, were found in a variety of glass-packaged foods; DBP, BBP and DEHP were found, as previously described, in butter and margarine as migrants from the aluminium foil-paper laminates; and DEP in pies at 1.8 micrograms/g (average) as a migrant from the pie carton windows. In most cases, plasticizers detected in the food were also found in the associated packaging. When possible, 'core' or non-contacting food portions were analysed to verify the migration phenomena.

Migration of polyisobutylene from polyethylene/polyisobutylene films into foods during domestic and microwave oven use

Migration of polyisobutylene from polyethylene/polyisobutylene film into foods has been studied in domestic applications such as wrapping of foods and reheating in a microwave oven. The results of these migration studies were obtained by direct measurement using newly developed analytical methods utilizing nuclear magnetic resonance (NMR) and infra-red (IR) spectroscopy as well as predictively from assessment of loss of polyisobutylene from the film. Total levels of polyisobutylene migration into cheese were found to be 8-10 mg/kg, into cake 1-5 mg/kg, and into sandwiches ranged from < 1 to 4 mg/kg. Reheating foods covered with film in the microwave oven, gave migration levels ranging from < 0.01 mg/kg for contact with steam only, up to 0.5 mg/kg for severe splashing of food onto the film and 4 mg/kg for reheated pizza. Migration of polyisobutylene was shown to be skewed towards the low molecular weight fraction of the additive. In typical films, the molecular weight range of polyisobutylene was shown to be 300-6000 daltons (95% limits) centred on 1300 daltons, whereas the additive that had migrated into cheese was found to range from 130-2200 daltons, centred on 520 daltons.

Studies into the transfer and migration of phthalate esters from aluminium foil-paper laminates to butter and margarine

Retail samples of Canadian butter and margarine wrapped in aluminium foil-paper laminate were found to contain dibutyl, butyl benzyl and/or di-2-ethylhexyl phthalate (DBP, BBP, DEHP) as packaging migrants at levels up to 10.6, 47.8 and 11.9 micrograms/g, respectively. These phthalates were determined by capillary gas chromatography with flame ionization detection (GC-FID) after clean-up of the separated oil by sweep co-distillation. The phthalate esters found in the contacted butter or margarine were also found in the contacting wrappers. They were determined in wrapper extracts by liquid chromatography with diode array detection or by GC-FID. Analysis of unused wrappers showed 76-88% of the total DBP and DEHP to be present on the foil (outer) surface as a component of the protective coating (washcoat). The remainder of the DBP and DEHP was found on the food-contacting paper surface, presumably by transfer from the outer to inner surface during storage in tightly wound rolls, although transfer of phthalate esters, if present in the paper-foil adhesive, cannot be ruled out. Food-contacting surface concentrations of DBP and DEHP were found to be 2.4 to 4.7 and 2.8 to 3.6 micrograms/cm2, respectively. Samples of each packaging component: paper, foil, adhesive, washcoat and inks were analysed for phthalate esters and only the washcoat was found to contain phthalate esters.