Evaluation of a predictive mathematical model of di-(2-ethylhexyl) adipate plasticizer migration from PVC film into foods

Sustainable Micro and Nano Additives for Controlling the Migration of a Biobased Plasticizer from PLA-Based Flexible Films

Plasticized poly(lactic acid) (PLA)/poly(butylene succinate) (PBS) blend-based films containing chitin nanofibrils (CN) and calcium carbonate were prepared by extrusion and compression molding. On the basis of previous studies, processability was controlled by the use of a few percent of a commercial acrylic copolymer acting as melt strength enhancer and calcium carbonate. Furthermore, acetyl n-tributyl citrate (ATBC), a renewable and biodegradable plasticizer (notoriously adopted in PLA based products) was added to facilitate not only the processability but also to increase the mechanical flexibility and toughness. However, during the storage of these films, a partial loss of plasticizer was observed. The consequence of this is not only correlated to the change of the mechanical properties making the films more rigid but also to the crystallization and development of surficial oiliness. The effect of the addition of calcium carbonate (nanometric and micrometric) and natural nanofibers (chitin nanofibrils) to reduce/control the plasticizer migration was investigated. The prediction of plasticizer migration from the films’ core to the external surface was carried out and the diffusion coefficients, obtained by regression of the experimental migration data plotted as the square root of time, were evaluated for different blends compositions. The results of the diffusion coefficients, obtained thanks to migration tests, showed that the CN can slow the plasticizer migration. However, the best result was achieved with micrometric calcium carbonate while nanometric calcium carbonate results were less effective due to favoring of some bio polyesters’ chain scission. The use of both micrometric calcium carbonate and CN was counterproductive due to the agglomeration phenomena that were observed.

In vitro dermal absorption of di(2-ethylhexyl) adipate (DEHA) in a roll-on deodorant using human skin

In vitro dermal absorption experiments were conducted using a roll-on deodorant that contains 1.56% di(2-ethylhexyl) adipate (DEHA), a plasticizer widely used in consumer products. Human skin specimens were fitted in Bronaugh flow-through Teflon diffusion cells. The diffusion cells were maintained at 32 °C to reflect the skin temperature. Two amounts (low dose: 5 mg of the product; high dose: 100 mg) were applied, in triplicate, each on four different human skins. DEHA was determined in the receiver solution at 6-h intervals, using headspace solid-phase microextraction gas chromatography-mass spectrometry (GC-MS). After 24 h, the experiment was terminated and masses of DEHA in the skin depot, skin wash, and upper and lower chambers of the diffusion cell were determined. A significant portion of applied DEHA, 28% in the low amount application and 34% in the high one, was found in the skin depot. In comparison, only 0.04% and 0.002% of applied DEHA were found in the receiver solutions for the low and high doses, respectively. Under our experimental conditions, an apparent steady-state flux of low DEHA mass penetrating from skin into the receiver solution was observed with a penetration rate of 2.2 ng/cm(2)/h for both the low and high doses. The average mass recovery was 81% for the low dose application and 56% for the high dose.

Migration of Substances from Food Packaging Materials to Foods

The employment of novel food packaging materials has increased the number of occurring hazards due to the migration from packaging material to the packaged food. Although polymers have mainly monopolized the interest of migration testing and experimentation, recent studies have revealed that migration also occurs from "traditional" materials generally considered to be safe, such as paper, carton, wood, ceramic, and metal. The regulations and the directives of the EU tend to become stricter in this respect. The emphasis is on reaching a consensus in terms of food simulants and testing conditions for migration studies. Furthermore, the list of hazardous monomers, oligomers, and additives continues to augment in order to ensure that the consumer safety is in current agreement with the HACCP, which is continuously gaining ground.

Contamination in food from packaging material

Packaging has become an indispensible element in the food manufacturing process, and different types of additives, such as antioxidants, stabilizers, lubricants, anti-static and anti-blocking agents, have also been developed to improve the performance of polymeric packaging materials. Recently the packaging has been found to represent a source of contamination itself through the migration of substances from the packaging into food. Various analytical methods have been developed to analyze the migrants in the foodstuff, and migration evaluation procedures based on theoretical prediction of migration from plastic food contact material were also introduced recently. In this paper, the regulatory control, analytical methodology, factors affecting the migration and migration evaluation are reviewed.

Stability testing of selected plastics additives for food contact in EU aqueous, fatty and alternative simulants

Within the framework of the AIR3-CT94-2360 EU-project, the stability of three plastics additives in three EU aqueous and fatty food simulants and in two alternative simulants was studied under various time-temperature conditions. The additives tested were bis(2-ethylhexyl) adipate (DEHA), bis(2-ethylhexyl) phthalate (DEHP) and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox 1076). The various test conditions included exposures of 10 days at 40 degrees C, 1 h at reflux temperature for all aqueous simulants, 10 days at 40 degrees C and 1 h 175 degrees C for the olive oil and 2 days at 20 degrees C and 3 h at 60 degrees C for the isooctane simulant. Following the exposure, the additive samples were extracted from aqueous simulants with hexane. A sonication step was necessary to ensure maximum extraction of control samples. In the case of the isooctane simulant, the samples were analyzed directly from the simulant. The oil samples were extracted by acetonitrile. The extracts of samples exposed to various heat conditions as well as unexposed spiked controls and blanks were analysed by gas chromatography (GC) on a non-polar (5%--phenyl)-methylpolysiloxane capillary column with high temperature capabilities. The results showed that DEHA, DEHP and Irganox 1076 were stable at 40 degrees C and at reflux temperature in ethanolic or acidic aqueous simulants. The various additives were also stable in the organic isooctane simulant as well as in the fatty simulant olive oil. Studies on the stability of such additives used in food packaging are designed for regulatory purposes as an aid to decide whether the legislation should regulate limits for plasticizers based on a quantity in the food packaging itself or based on an ingested dose by the consumer.

Assessing the suitability of recycled plastics used as agricultural soil covers: migration study and experimental harvest

The present work is focused on evaluating the suitability of recycling postconsumer agricultural plastic films again for the same use. The criteria to assess the suitability was based on migration study. Both overall and specific migration tests were performed, and the results obtained (ranging from 0.14 to 1.27 mg/dm(2) for overall migration and from not detectable to 6.98 microg/dm(2) for specific migration) show how, from this point of view, the recycled material can be safely proposed to be used again as agricultural soil covers. A theoretical discussion about the migration process is also presented and a simple mathematical model was applied to the data obtained, showing how total migration which is experimentally detected is theoretically predictable. These conclusions found were used to design and develop a controlled crop of tomato by using this recycled film. The use of the recycled plastic in the whole process and the behavior and properties of the pesticides absorbed in the postconsumer film are discussed.

Methods and approaches used by FDA to evaluate the safety of food packaging materials

In the Federal Register of July 17 1995 (60 FR 36582), the US Food and Drug Administration (FDA) established a 'threshold of regulation' process. This process was established for determining when the extent of migration to food is so trivial that safety concerns would be negligible. The process exempts materials in food-contact articles whose use results in dietary concentrations at or below 0.5 ppb (microgram/kg) from the food additive listing regulation requirement. Carcinogens or substances that may be carcinogens are excluded from this regulation. This paper explores some of the ramifications of the threshold of regulation policy with respect to traditional migration testing. It examines the use of the threshold approach and migration modelling to estimate food additive exposures. These results indicate that modelling may be a reasonable alternative to traditional migration testing.

Prediction of worst case migration from packaging to food using mathematical models

Prediction of migration from packaging to food is often made using equations which are not always designed specifically for the problem. At least, these equations should overestimate migration, in order to be on the safe side. Integration of Fick's equation under the assumption of 'infinite packaging' provides an equation which is very practical since it requires only a few experimental data. It is shown here that, unfortunately, the use of this equation leads to a systematic underestimation of the diffusivity, by the square of the percentage of migration at steady state. In contrast to widely accepted opinion, this model is not conservative. A conservative approach requires that the diffusivity is determined under 'finite packaging' assumptions, associated with very large volumes of food and with long term experiments. These equations are applied to the migration of a phenolic antioxidant from polypropylene.

Migration from plastic packages into their contents. I. The role of mathematical models

Materials contained in plastic packages can transfer (migrate) into the contents. In some circumstances, such as packages of food, drink or medicine, the consequences of this migration can be unpleasant or even harmful. Many countries, and the European Community, have adopted legal regulations designed to limit the amount of migration. It is shown, partly by discussing one example in some detail, that certain quantitative criteria in such regulations are unsatisfactory. The reasons include ( a ) improper recognition of the importance of package geometry, ( b ) invalid assumptions about a correspondence between concentrations in the contents and mass transfer per unit area of the package-contents interface and ( c ) failure to account, in an adequate manner, for the inevitable variability between nominally identical package systems. The principal theme of the paper is that these faults could have been, and can be, substantially ameliorated by proper use of mathematical models. Common shortcomings in the previous (but very limited) use of mathematics are exposed partly by detailed examination of a recent research paper. The paper discusses the requirements of a successful model and considers the simplest type, namely diffusion equations with diffusion coefficients that are independent of the concentrations of the migrant in either the plastic or the contents. Particular solutions are chosen to illustrate faults in existing legislation and practice, and because they are thought to be good candidates for testing against data. It is argued that future experiments would be more successful and more useful if they were planned and conducted in teams involving mathematicians.

A review of the research requirements for Europe to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision making process involved in determining future European Community legislation in the area of food contact materials and articles. The generation of this science base should be undertaken on a Europe-wide basis and needs to be coordinated to avoid duplication of effort and to secure agreement on the underlying science being used to determine future strategy. This review considers possible work that might be required in the future to support legislation on food contact materials and classifies it in terms of short-term problem-solving and longer-term strategic research.

Plasticizers from printing inks in a selection of food packagings and their migration to food

A survey of plasticizers in printing inks present in a selection of food packaging including confectionery, snacks, crisps, potatoes, chocolate bars and biscuits, has been carried out both in England and Spain. The identification of the polymer used as packaging showed that almost all of them were oriented polypropylene. Printing inks that are always used on the outer surface contain phthalates as major plasticizers, N-ethyl- and N-methyl-toluenesulphonamides and tris(2-ethylhexyl)trimellitate were found in some of the samples studied. Several food samples were also analysed to check the level of plasticizers migrating from printing inks.

Migration of mineral hydrocarbons into foods. 3. Cheese coatings and temporary casings for skinless sausages

Levels of mineral hydrocarbons which have migrated from wax coatings into cheese have been determined for 20 retail samples using a gas chromatographic procedure. Contamination was limited to the outermost 2 mm of cheese in direct contact with the wax where levels of hydrocarbons were found to range from 10 to 150 mg/kg. On a whole cheese weight basis these amounted to < 1 to 27 mg/kg (< 0.2 to 3 mg/dm2 contact area). Components attributed to hydrocarbons in cheese samples remote from the waxed surface (background levels) were typically 3-5 mg/kg. Background levels were subtracted from the results for surface samples to obtain migration values. There was evidence that the surface contamination of cheese with mineral hydrocarbons occurred by a combination of diffusion into the cheese and adhesion of wax components onto its surface. Mineral hydrocarbons are used in the manufacture of the temporary casings used to mould skinless sausages. Of 33 retail products examined, including skinless sausages, hot-dog sausages and frankfurters, 25 (75%) contained levels of mineral hydrocarbons from 10 to 105 mg/kg. These hydrocarbons were shown to be present principally at the surface of the food and so could be attributed to migration. Nine other minced meat products were examined for comparison, including minced beef, pâté, sausage meat and sausages with skins. Levels of mineral oil in these products were insignificant by comparison, typically below the limit of detection of ca 4 mg/kg, indicating insignificant adventitious contamination from routes other than migration.