Recent progress in safety evaluation studies on plasticizers and plastics and their controlled use in Japan.

Recent experimental studies in Japan on the evaluation of potential health hazards from phthalate esters used in manufacturing poly (vinyl chloride) as well as several plastics for medical devices and for food containers and packages were introduced. Development of pulmonary granuloma formation after intravenous injection of diethylhexyl phthalate was assumed to be dependent on the particle size of the phthalate in vehicle used. Dietary administration of large amount of diethylhexyl phthalate and dibutyl phthalate produced renal cysts in mothers and in descendants in reproduction studies in mice. Cytotoxicity and mutagenicity of the phthalates and several plastics and resins were also examined by in vivo and in vitro studies. Hematological parameters examined in rabbits after repeated intravenous injection of diethylhexyl phthalate and after implantation of plastics in aorta for 3--6 months did not show any significant change. A slow decrease of radioactivity was observed in adipose tissue of rats following oral administration of 14C-labeled diethylhexyl phthalate. tthe administrative action on phthalates by the Japanese Ministry of Health and Welfare is briefly reviewed.