Soothers, rubber

Three groups of substances are regulated individually, i.e. vinyl chloride monomer in plastics (78/142/EEC), nitrosamines in rubber teats and soothers (93/11/EEC), and bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and novolac glycidyl ethers in plastics and coatings (2002/16/EC). 

Draft directive on nitrosamines in rubber teats and soothers... 

On 15 March 1993 the Commission adopted Directive 93/11/EEC concerning the migration of N-nitrosamines and N-nitrosatable substances from elastomer or rubber teats and soothers. This Directive stipulates that these articles must not release any N-nitrosamine and N-nitrosatable substance detectable by a validated method able to... 

In the 1980s it became evident that rubber teats and soothers may release carcinogenic nitrosamines, which are reaction and degradation products from accelerators and stabilisers used in the mbber. Legislation contained in Directive 93/11/EEC prescribes that nitrosamines and nitrosatable substances that can be transformed into nitrosamines in the stomach shall not be released from the teats and soothers in detectable quantities. Methods for the analysis are proposed with the detection limit set to 0.01 mg/kg rubber for nitrosamines and 0.1 mg/kg rubber for nitrosatable substances. 

Commission Directive 2004/14/EC of 29 January 2004 amending Commission Directive 93/10/EEC relating to materials and articles made of regenerated cellulose film intended to come into contact with foodstuffs. OJ L 27, 30.1.2004, p. 48. Commission Directive 93/11/EEC of 15 March 1993 concerning the release of the N-nitrosamines and N-nitrosatable substances from elastomer and rubber teats and soothers. OJ L93, 17.4.1993, p. 37. 

Special Category (test 24 hours at 40 °C). Rubber articles directly associated with the consumption of food and which are being, or are expected to be, taken into the mouth, e.g., toys according to Recommendation XLVll, teats, soothers, gum-shields, balloons. 

A more recent Dutch retail survey looked at the migration of A-nitrosamines, A-nitrosatable substances and 2-mercaptobenzothiazole (MET) from 19 samples of teats and soothers. In addition to these species, screening work was also carried out for any other potential migrants. The majority of the teats and soothers were found to be based on sihcone mbber, and the extractable substances were found to be siloxanes. The remaining samples were natural rubber and only one was found to be above the permissible limits, and that was for nitrosatable substances at 0.23 mg/kg. MET was found in only one of the natural rubber products and this was below the migration limit of 0.3 mg/teat. 

A silicone rubber can be bonded to a solid substrate if it is clamped into or onto it. A very good example is the baby soother. The silicone nipple is injection moulded by a common LR process and then post cured. After that the nipples are clamped into a plastic construction or even overmoulded by thermoplastic. 

The current state of knowledge on N-nitrosamines formation in production processes in the rubber industry is presented. Taking into account that N-nitrosamines are toxic and carcinogenic, or probably carcinogenic for human beings, their emission creates threat for environment and health particularly in the case of rubber goods intended for direct contact with foodstuffs and humans, especially children (soothers, toys etc.) The origin of N-nitrosamines formation in the rubber industry is described. Raw materials, mainly vulcanisation accelerators, which can cause N-nitrosamines formation, are characterised and necessary measures to ehminate their emission or reduce concentration are presented. The best way is to apply safe accelerators which are not... 

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