Additive migration from packaging polymer additives

It should not be forgotten that, in addition to additives which are deliberately introduced into the resin, plastics may contain substances that are residues of substances produced or introduced at some stage of polymerization or processing, such as residues of catalysts, solvents, or unreacted monomer or substances which have migrated into the polymer from the contents of the package or from its surroundings. 

Two methods are used to monitor concentration and to restrict excessive use of polymer additives in contact with food quantity in the materials and specific migration hmit. If a compound degrades in a food simulant, the quantity in the material should be used. From this follows that for stability of additives it is important to establish which parameter has to be controlled. Low molecnlar weight plasticizers, such as di-(2-ethylhexyl) adipate and di-(2-ethylhexyl) phthalate, are known to migrate into food on contact. Their studies in various food simulants show that both materials are fairly stable and thus the quantity in the material is postulated to be used in screening of packaging materials. ... 

Identification and eventual determination of polymer additives is an important issue in many fields, mainly in the area of packaging materials where additive migration from food contact materials may have potential toxic effects in humans.In biomedical applications, plasticizers present in the polymer [e.g., Di(2-ethylhexyl) phthalate (DEHP) in PVC] will readily leach into the liquids passing through it, particularly for lipid-containing fluids, e.g., blood. There is a great concern about the toxicity of DEHP, especially for risk groups such as... 

The compatibility of the plasticizer in the PLA matrix, the morphological stability of the plasticized material and the prevention of the plasticizer migration from the material bulk should be optimized as leaching out of additives from materials could impact the media in contact. This is of particular importance where food packaging applications are concerned, because food safety has to be ensured and contamination risks should be minimized. As with all substances intentionally added to the packaging polymer, the choice of plasticizer must comply with the European Commission regulation EU 10/2011 on plastic materials intended to come into... 

Haidary SM, Corcoles EP, Ali NK (2013) Folic acid delivery device based on porous silicon nanoparticles synthesized by electrochemical etching. Int J Electrochem Sci 8 9956-9966 Heirlings L, Siro I et al (2004) Influence of polymer matrix and adsorption onto silica materials on the migration of alpha-tocopherol into 95 % ethanol from active packaging. Food Addit Contam 21 1125-1136... 

Eberhardt and McCort-Tipton [23] have also applied HPLC-MS to the determination of species such as monomers, oligomers, additives and modifiers which have migrated from polymers into packaged foods. 

The plastics manufacturer must consider his product from the points of view of basic polymer, additives/adjuvants and migration of anything from the plastic into the packaged commodity. 

We have known for years that the behaviour of volatile materials migrating from and through plastics can be described by Pick s Law of Diffusion. Theory and practical experience with these materials indicate that they can be monitored to ensure their safe and satisfactory use with foods. But the migration of non-volatiles from plastics is by no means so well understood and has been the subject of research, not only at PIRA, but at several other Packaging Research Laboratories over the last five years. Simple model migration systems have been used at PIRA for example, systems based on a single polymer containing one non-volatile additive, exposed to pure liquids either separately or in mixtures. The major results of this work are as follows ... 

Whilst migration of additives from a polymer matrix with time may be acceptable from the point of view of the polymer properties, contamination of materials, e,g, foods, in contact with the polymer is unacceptable. National standards have been laid down for acceptable limits of additive migration in food packaging materials. ... 

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