|IDENTIFICATION AND USE: Beta-ionone (BI) is a colorless to pale, straw-colored liquid. BI is of use, not only in perfumery, but also as a key intermediate in the synthesis of Vitamins A, E, and K.
HUMAN EXPOSURE AND TOXICITY: At 1% BI produced no irritation or sensitization in patients. At 5% concentration, 2 patients showed questionable positive irritation reactions, but there was no sensitization.
ANIMAL STUDIES: No evidence of sensitization was observed in guinea pigs. In rabbits application of neat beta-ionone produced very slight to well-defined erythema on the abraded and intact skin at 24 hr and well defined erythema at 72 hr. Very slight conjunctival irritation was observed in all three rabbits at 0, 1, 2, and 4 hr with neat BI. In 90 day feeding study in rats BI did not produce adverse effects. In development study in BI-treated pregnant rats compared to the untreated controls, the uterus weight, the ratio of resorptions per implantations and the percentage of resorptions per implantation per litter were substantially increased, and the ratio of live fetuses per implantations per litter was drastically decreased with 1000 mg/kg; with 250, 500 and 750 mg/kg, no effects were produced. BI exhibited no mutagenic activity in Salmonella typhimurium (strains TA98, TA100, TA1535 and TA1537) at concentrations up to approximately 180 ug/plate with and without metabolic activation.
ECOTOXICITY STUDIES: Ultrastructural examination by transmission electron microscopy indicated that the thylakoids were distorted, and the thylakoid membrane stacks began to collapse when M. aeruginosa NIES-843 was exposed to BI at a concentration of 22.5 and 33.75 mg/L.