13-week oral toxicity study of vinyl laurate in rats.

Vinyl laurate (VL) is used as a monomer in the production of polyvinyl acetate vinyl laurate copolymer, a component of chewing gum base. The safety of VL was examined in a 13-week oral toxicity study in Wistar rats. VL was administered in corn coil by daily gavage (5 ml/kg bw/d) to four main groups (10 rats/sex) at doses of 0 (vehicle only), 50, 250 and 1000 mg/kg bw/d, respectively. The control and high-dose group comprised an additional 5 rats/sex which were kept untreated for a further 4 weeks until sacrifice (recovery groups). In addition to standard parameters, male and female fertility parameters were determined as well. There were no mortalities and treatment-related clinical signs. Neurobehavioral observations and motor activity assessment, ophthalmoscopic examinations, body weights, feed and water intakes, blood cell counts, coagulation time, standard clinical chemical parameters and urinalyses, absolute and relative organ weights at the end of the treatment as well as macroscopic examination at necropsy and microscopic examination of standard organs and tissues did not show any treatment-related changes. Female and male fertility parameters (estrus cyclicity, testicular and epididymal sperm counts, sperm motility and morphology) were not affected by the treatment. Accordingly, the no-observed-adverse-effect level (NOAEL) for VL was determined to be 1000 mg/kg bw/d, i.e. the highest dose level tested.