Detection And Safety Assessment On Substances Of Very High Concern In Food Contact Silicone Rubber Materials

Owing to unique performance advantages,silicone rubber is widely used as food contact materials,such as infant feeding utensils,bakeware,kitchenware and tableware.Some intentionally added substances(such as organic solvents,plasticizers,colorants,antioxidants,vulcanizants,etc.)and non– intentionally added substances(such as reaction products and degradation products,etc.)in the production process of silicone products,may remain in the final products and migrate to food,which pose a potential risk to human health.In this study,a total of 122 food contact silicone rubber products including infant nipples,bakeware,kitchenware and tableware were selected as research object.The substances with high content,high toxicity and high detection rate,namely “substances of very high concern”(SVHC),were systematically studied for the first time,which included the screening,detection and safety assessment of SVHC.Firstly,on the basis of the results of our previous research,according to the molecular weight,content,toxicity,detection rate and qualitative accuracy of a large number of non–target substances,the “five step screening system” for silicone products were established.After screening through this system,methylsiloxanes,phthalates(PAEs),saturated hydrocarbon mineral oil(MOSH),aromatics,aromatic amines,thiazoles etc.were screened.Secondly,the high efficient,sensitive and reliable detection methods of these SVHC(except methylsiloxane)in the silicone products were established respectively.The content determination and migration experiments were carried out by these methods.These methods included ultrasonic–assissted solvent extraction–gas chromatography tandem mass spectrometry(UASE–GC–MS/MS)for analysis of 16 PAEs in products and QuEChERS–GC–MS/MS for their migration in food,UASE–GC–MS for MOSH and their migration in liquid food simulants,solid phase microextraction(SPME)–GC–MS/MS for 9 aromatics,and UASE–GC–MS/MS for N–methylaniline(NMA),dimethylphylamine(DMA),nonanal,benzothiazole(BTZ),butylated hydroxytoluene(BHT).Finally,according to the results of the detection and exposure assessment,combined with existing regulations and limits at home and abroad,the preliminary safety assessment of the above SVHC in the food contact silicone rubber products was carried out.The results showed that the safety risks of some SVHC such as PAEs,MOSH and aromatic amines in the food contact silicone rubber products need special attention and in–depth study.