Specific migration limits plastics

At the time of writing, DEHA has not yet been included in the EU positive list of additives used to make food contact plastics. With an established TDI of 0.3 mg/kg bw/day and using the normal conservative assumptions of 1 kg food consumed daily and a 60 kg bw, this TDI would give a specific migration limit of 18 mg DEHA per kg food or food simulant. It must be recognised that non-compliance with a migration limit of 18 mg/kg based on this convention does not necessarily mean that the TDI could be exceeded. It seems unlikely that DEHA will be listed until the issue of food consumption factors is resolved. 

Basic requirements for active and intelligent materials have been set in the Framework Regulation. However, some issues need further clarification. The main issues are the applicability of the requirements of the plastics directive to active and intelligent plastic materials, especially compliance with overall and specific migration limits, rules for non-plastic active and intelligent materials, risk assessment of active ingredients and if necessary conditions/restriction of their use, and mles on the efficacy of the materials in relation to instructions for their use and protection of the consumer. 

Water-based adhesives are used in the production of paper and cardboard food packaging. Migration of adhesive components from such packaging has been assessed. Migration levels into a food simulant (Tenax) were lower than the specific migration limits for plastics which were used to provide a convenient, informal way of assessing the results. Migration to foodstuffs would be expected to be even lower than into the Tenax simulant used, because food will not be in direct contact with the adhesive surfaces. 

In the absence of specific legislation for the other (non-plastic) food contact materials used in take-away and snack food packaging then the plastics legislation is used as a guide, although limits are not taken as presumptive standards. Where possible, in the absence of specific migration limits (SMLs), levels found are related back to exposure restrictions such as tolerable daily intake (TDl) or acceptable daily intake (ADI). 

If a material is not listed in the pharmacopoeia then reference must be made to a further Directive dealing with plastic materials in contact with food. Materials authorised for use in contact with food are generally acceptable for contact with pharmaceuticals (Table 3.12), but if this approach is taken it will also be necessary to provide a list of countries where the plastic has been approved for pharmaceuticals. If these two aspects can be covered, then toxicology data should not be required in the application. The Plastic Material in Contact with Food Directive lists, in an annexe, the monomers and starting materials which can be used for food purposes after January 1997. A second annexe lists the monomers which can be used, but which may be deleted if data were not supplied to enable the Scientific Committee to evaluate the product before 1 January 1996 (since then amendments have been inserted updating Annexe 1 as the data have been provided). Finally, specific migration limits are given for each material listed. 

The EU Directive 2002/72/EC regulates plastics intended to come in contact with food, where the principle of regulation is the establishment of a positive list, which presently is restricted to monomers and start substances. Directive 2002/72/EC (and its amendment 2004/19/EC) contain in their Annexes I-IV, lists of evaluated monomers and additives and the corresponding specific migration limit (SML) values. SML is expressed as the amount of a substance (mg) allowed to migrate from the plastic into 1 kg of food. The law requires compliance with the SML for the end-use material, in addition to the requirement of compliance with the overall migration limit (60 mg/kg food). 

Vinyl chloride monomer used for the manufacture of PVC plastics intended for contact with foods provides an example where there is a low specific migration limit , plus a low limit on the level allowed to be present in the packaging material. These limits are contained in an EC Directive 78/142/EEC on PVC plastics and are 0.01 milligrams per kilogram of food (lOppb), and 1 milligram per kilogram of polyvinyl chloride. 

For substances with proven toxic effects. Specific Migration Limits (SMLs) have been declared in food simulants or the maximum amounts in a given material for unstable compounds are stated. An example can be the SML for melamine (2,4,6-triamino-1,3,5-triazine), which is set at 30 mg/kg. On the other hand, acrylamide cannot be detected at all in the migration tests (its detection limit is 0.01 mg/kg), although it is known as a common process contaminant. The SML value for dibutyl phthalate is 0.3 mg/kg and for bis(2-ethylhexyl) phthalate 1.5 mg/kg, but plasticised plastics should not be used for fatty foods. In sealing lids for jars intended for infant and baby food, the migration of epoxidised soybean oil is often controlled (SML = 30 mg/kg). 

In addition to the global migration limit 90/128/EEC also provides a number of specific migration limits (SMLs) for plastic monomers (Table 9). 

General information about how to determine specific migration is available in CEN document EN 13130-1 2004 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 simulants and the determination of substances in plastics and the selection of conditions of exposure to food simulants . CEN has also established methods for the determination of some specific migration. Table 5.4 is a list of components for which CEN methods are established. Another source of methods for the determination of specific migration can be found at http // cpf.jrc.it/smt/. At this website of the Joint Research Centre methods are collected and made public online. A summary of the methods available at the website of JRC is given in Table 5.5. 

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