Specific migration limits

Petersen et al. (1997) reported that, compared with a specific migration limit of 3 mg di(2-ethylhexyl) adipate/dm from PVC cling films used in Denmark, 77% of the films used for fatty foodstuffs sampled from importers, wholesalers and retail shops... 

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. 

One laboratory has carried n measurements under repeatability conditions and obtained an average value y which is compared with a given value m0 (e.g. a specific migration limit). Then one obtains the critical difference as ... 

Restrictions applicable to authorised substances, expressed in maximum quantity in the finished product except for the limits for MEG and DEG expressed as specific migration limits (= 30 ppm in foodstuffs)... 

In 1984, after some ten years of discussion, Directive 84/500/EEC on ceramic articles was approved it lays down the specific migration limits for lead and cadmium, according to their intended uses, along with the essentials of the method for checking... 

Thble 12-5 Specific migration limits for lead and cadmium. 

R = restriction recommended by SCF which may be expressed in a specific migration limit or a value expressed in mg/kg p.c. or in some other way. 

QMcaic means the maximum allowable concentration of the substance in the polymer that will not exceed the specific migration limit in the food for given time and temperature storage conditions. 

The verification of compliance with the specific migration limits (SML) provided in the Directives may be replaced by the verification of compliance with the maximum permitted quantity of substance in the finished product (QM), which corresponds to the SML. The correspondence between the specified SML and the QM shall be established by a calculation based on adequate experimentation of the finished product or by the application of generally recognized diffusion models. However, if the limit of QM is exceeded, for a judgement of non compliance of the material or article, it is necessary to obtain a confirmation that the SML has been exceeded . 

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. 

Specific migration is the amount of a specific component that migrates from the food contact material to the food during contact. There are several ways to demonstrate compliance of the specific migration limits (SMLs) set in EU food contact legislation. The generic approach is shown in Fig. 5.2. For every component with a specific migration limit that is present in a material the procedure in Fig. 5.2 must be completed. 

Restrictions for the residual amount of a component instead of a specific migration limit are set by the legislator in cases where specific migration of a component is difficult to obtain (for example, because the component is very volatile) or impossible to determine directly (for example, if the component is very reactive and would react with the food simulant). There are two ways to determine the residual content, by worst-case calculation or by analytical determination. The generic approach is shown in Eig. 5.3. 

Demonstration of compliance with specific migration limits may be accomplished by two simple procedures that should be considered first before any testing is conducted. 

SML = specific migration limit in food or food simulant. 

Category 111 comprises mbber products for which the R-total is smaller than 0.001 and for which migration testing is not required, except for mbber products containing nitrosamines, nitrosatable substances or aromatic amines and Category 111 substances with a specific migration limit (SML) in Technical document No. 1. 

It has already been mentioned (section 12.3) that the National regulations and the Council of Europe resolution stipulate concentration limits for certain species within food contact rubber compounds and that they have specific migration limits (SMLs) for certain migrant compounds. Analytical work is therefore required on a quality assurance basis ... 

The CoE resolution on packaging inks is accompanied by a couple of technical documents (TDs). TD 1 provides the requirements for selecting packaging ink substances. It comprises a scheme, an inventory list of substances being used by the industry and an exclusion list. Substances that are evaluated by an international body are noted, and specific migration limits are given, if available. The purpose of TD 1 is to ensure that no substances that are harmful to human health, are transferred into the packed foodstuff. 

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. 

---