Plastics are generally mixed with additives like plasticizers to enhance their flexibility, pliability, and elasticity proprieties. Plasticizers are easily released into the environment and are absorbed mainly through ingestion, dermal contact, and inhalation. One of the main classes of plasticizers, phthalates, has been associated with endocrine and reproductive diseases. In 2002, 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) was introduced in the market for use in plastic materials and articles intended to come into contact with food, and it received final approval from the European Food Safety Authority in 2006. 1,2-Cyclohexanedicarboxylic Acid, Diisononyl Ester is a non-phthalate plasticizer that is well suited for PVC applications including flooring, wall coverings, films, hoses, adhesives and sealants. It is non-toxic and SVOC free, making it a prime choice for applications where PVC comes in close human contact. Its performance properties are excellent for both thermoplastic and plastisol in terms of cold flexibility, rheological properties, hydrolytic stability, migration, and UV stability.
DHIN can be produced by the catalytic hydrogenation of diisononyl phthalate. Alternatively it can be prepared by Diels-Alder reaction of a diisononyl maleate with 1,3-butadiene followed by hydrogenation. In the case of the catalytic hydrogenation the aromatic, planar part of the diisononyl phthalate is transformed to a cyclohexane ring. Commercial DINCH consists of 90% of the cis and 10% of the trans (chiral) isomers.
In the European Union the European Food Safety Authority approved DHIN for a wide variety of food contact applications in October 2006. In 2007 DINCH has been added to regulation list relating to plastic materials and articles intended to be allowed to come into contact with food.
In the European Union 1,2-cyclohexane dicarboxylic acid diisononyl ester was not listed in as dangerous good. However, some restrictions for certain phthalates are now transferred into regulated which ban the use of certain phthalates in toys and childcare articles and thus DHIN can be used safely in toys and childcare articles.