Migration Test, conditions

An important conclusion from these findings was that even though this analytical method works in principle with olive oil as a food simulant, the migration test using olive oil or another fat simulant can provide false-negative results. Therefore, the method should only be applied in the case of short exposure periods with olive oil. If the method is carried out with olive oil, a recovery check with spiked olive oil applying the same time/temperature migration test conditions is necessary. In the case that such a recovery check indicates loss" of HMDA and/or EDA, then alternatively 95 % ethanol or iso-octane should be used as substitute fatty food simulants. 

Philo M R, Jickells S M, Damant A P and Castle L, 1994, Stability of plastics monomers in food-simulating liquids under European Union migration test conditions. J. Agric. Food. Chem. 42,1497-1501. 

The US and EU accelerated migration test conditions for long term ambient storage, 10 d at 49 °C and 10 d at 40 °C, yield equivalent migration values to those calculated in Example 14-3 for ambient storage at 23 °C for six months ... 

Actual storage/filling EU Migration test conditions FDA Migration test conditions2... 

The electrochemical migration test requires that any degradation in insulation resistance value be less than a decade. The Telcordia Electrochemical Migration test method has also become an IPC test method (TM 2.6.14.1). Table 1 compares the variation in SIR and electrochemical migration test conditions for telecommunications test versus the non-telecommunication applications. 

Applications Radiotracer measurements, which combine high sensitivity and specificity with poor spatial resolution, have been used for migration testing. For example, studies have been made on HDPE, PP and HIPS to determine effects of manufacturing conditions on migration of AOs from plastic products into a test fat [443]. Labelled antioxidant was determined radio-analytically after 10 days at 40 °C. Acosta and Sas-tre [444] have used radioactive tracer methods for the determination of styrene ethyl acrylate in a styrene ethyl acrylate copolymer. 

As one moves down the chain of use, to the converter, the packer and finally to the retailer, full disclosure of this compositional information and manufacturing history can be difficult to obtain and verify. These users will require a compliance statement from the primary manufacturer but will need also to conduct migration tests themselves to ensure that the conversion process and conditions of actual use, do not cause unacceptable migration. 

At microactivity test conditions (MAT), the mechanism of vanadium migration has been found to be a gas-phase transport phenomena (20,23). However, a particle contact interaction mechanism has also been suggested (21). Formation of surface compounds, such as heat stable vanadates (5), may help explain V migration and V induced FCC deactivation. Few experimental investigations of metal migration between the various FCC components have been reported. 

Figure 10-3 Estimation of migration (standard test conditions of 10 days/40°C) as a function of Cp0 and in dependency of molecular weight of migrant from a HDPE container of thickness dP = 0.06 cm at a surface/volume ratio of 6 dm2/kg assuming a partition coefficient KPp = 1.

The test principle is such that the extraction of migratable substances from a sample of the plastics is determined as the mass of non-volatile residue after evaporation of the solvent following immersion. Test specimens of at least 1 dm2 (single side considered) are immersed in the extraction solvent at the specified test conditions and then... 

In 1982 the first directive in the sector, Council Directive 82/711/EEC, laying down a precise reference framework for the system of checking specific and/or overall migration, was adopted. It establishes what simulating liquids (i.e. liquids which can simulate the extractive capacity of foodstuffs), contact times and temperatures are to be used in migration tests performed under standardized conditions. This reference framework, which may seem unduly rigid given the innumerable conditions of contact in reality, was made flexible by the inclusion of a clause which permits Member States to depart from the standard conditions where these prove to be inadequate in the case in question either for technical reasons or because they are too different from the real conditions. 

Moreover, the first amendment to it, Council Directive 93/8/EEC, made the standard conditions for migration tests more flexible by allowing a greater number of possible combinations of times and temperatures and the use of other simulants for the fat test in cases where it is not possible to use those previously provided for. Table 12-9 shows the conditions which now apply. 

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