[Consideration of the Evaporation Residue Test for Plastics Intended to Contact with Oils and Fatty Foods].

The Japanese Food Sanitation Act designates the evaporation residue test as a specification for plastics that intended to contact with foods. The test conditions and migration limits for oils and fatty foods were considered on the basis of the results obtained from the evaporation residue test according to the Japanese Act and the overall migration test into olive oil according to EN1186-2. The evaporation residue test was conducted using heptane at 25℃ for 1 hour. The results of most samples were under 30 µg/mL although those of high impact polystyrene,polymethylpentene and polyvinyl chloride were found to be over 30 µg/mL. However, these results were within the acceptable range of the relaxed limits (240, 120, 150 µg/mL). Regarding the overall migration into olive oil, most plastics were under the determination limit at 60℃ for 30 min. But the results for polyethylene, polypropylene and polyvinyl chloride were over 30 µg/mL at 95 and 121℃, which were higher than their evaporation residues. In other words, the existing test conditions and limits of the evaporation residue test could be used for testing plastics that come into contact with oils and fatty foods at lower temperatures. However, they are not adequate for evaluating some plastics that come into contact with oils and fatty foods at higher temperatures.

[Interlaboratory study on migration test of cadmium and lead for food contact articles].

An interlaboratory study was performed to evaluate a migration test method of cadmium (Cd) and lead (Pb), based on the Japanese Food Sanitation Law for glassware, ceramicware, enamelware and metal cans. Seventeen laboratories participated, and quantified Cd and Pb in eight test solutions as blind duplicates using flame atomic absorption spectrometry (AAS), graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma-optical emission spectrometry (ICP-OES) or induced coupled plasma-mass spectrometry (ICP-MS). Statistical analysis revealed that the trueness, repeatability (RSDr) and reproducibility (RSDr) were 93-105%, 0.7-8.4% and 2.6-19.3% by using AAS, ICP-OES and ICP-MS (internal standard method). The performance of these methods is sufficient for testing specifications. However, some of the RSDr values exceeded 10% in GF-AAS, and careful control of accuracy is required.

[Performance comparison of material tests for cadmium and lead in food contact plastics].

Based on the Japanese Food Sanitation Law, the performances of official and alternative material test methods for cadmium (Cd) and lead (Pb) in food contact plastics were compared. Nineteen laboratories participated to an interlaboratory study, and quantified Cd and Pb in three PVC pellets. in the official method, a sample is digested with H2SO4, taken up in HCl, and evaporated to dryness on a water bath, then measured by atomic absorption spectrometry (AAS) or inductively coupled plasma-optical emission spectrometry (ICP-OES). Statistical treatment revealed that the trueness, repeatability (RSDr) and reproducibility (RSDr) were 86-95%, 3.1-9.4% and 8.6-22.1%, respectively. The values of the performance parameters fulfilled the requirements , and the performances met the test specifications. The combination of evaporation to dryness on a hot plate and measurement by AAS or ICP-OES is applicable as an alternative method. However, the trueness and RSDr were inferior to those of the official method. The performance parameters obtained by using the microwave digestion method (MW method) to prepare test solution were better than those of the official method. Thus, the MW method is available as an alternative method. Induced coupled plasma-mass spectrometry (ICP-MS) is also available as an alternative method. However, it is necessary to ensure complete digestion of the sample.