Effect of the Nature and Concentration of Phthalates on Their Migration from PVC Materials Under Dynamic Simulated Conditions of Mouthing

摘要

Polyvinylchloride (PVC) has been a very common material for the production of toys. It generally is manufactured with an addition of additives such as plasticisers to improve its functionality and facilitate its production process. PVC that can contain up to 50% by weight of plasticisers (Simoneau et al., 2001). Among plasticisers, 90% of the most commonly used to soften polymers for toys production are constituted by phthalates, such as diisononyl phthalate (DINP). The purpose of this study was to investigate the influence of the relative concentration of percentage of phthalates and nature of phthalates on their release in standard conditions. To obtain a suitable but rapid method of analysis, experiments were performed to study the effects on the modification of a standard operation procedure (SOP) previously validated at the EU level by JRC Ispra. A single extraction with a sufficient large volume of cyclohexane thus could be used instead of two extractions with a smaller volume of cyclohexane and resulted in more rapid yet reliable method. The final method is described in Annex 1 of this report. Samples of soft PVC were industrially produced especially for this study. Standard PVC disks with various percentages of di-isononyl phthalate (DINP), di-isodecyl phthalate (DIDP), di-ethyl-hexyll phthalate (DEHP), benzylbutyl phthalate (BBP) dibutylphthalate (DBP) or a binary mixture DINP/DBP in various proportions were prepared. 30 different types of disk were produced and tested. The disks were analysed for contents, homogeneity and sets were subjected to migration experiments of the various phthalates under dynamic conditions using the previously validated SOP with some modifications. The release from samples with a systematic manufacturing process and containing different phthalates at different concentrations showed correlations to their concentrations. Since previous studies using commercial toys had no showed such specific trends, these results suggest that the production process of toys may be an important issue with respect to release properties. The release of DEHP BBP and DBP tended to show a more linear correlation to the concentration, whereas for DINP, DIDP, DEHP and release the plasticiser showed non linear tendencies and saturation of release for high formulation contents.