Update to RIFM fragrance ingredient safety assessment, 4,4a,6,7,8,8a-hexahydro-1,4-methanonaphthalen-5(1H)-one, CAS Registry Number 51519-65-4

Abstract

4,4a,6,7,8,8a-Hexahydro-1,4-methanonaphthalen-5(1H)-one was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, photoirritation/photoallergenicity, skin sensitization, and environmental safety. Data show that 4,4a,6,7,8,8a-hexahydro-1,4-methanonaphthalen-5(1H)-one is not genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class III material, and the exposure to 4,4a,6,7,8,8a-hexahydro-1,4-methanonaphthalen-5(1H)-one is below the TTC (0.0015 mg/kg/day, 0.0015 mg/kg/day, and 0.47 mg/day, respectively). Data from read-across analog octahydro-7-methyl-1,4-methanonaphtalen-6(2H)-one (CAS # 41724-19-0) provide 4,4a,6,7,8,8a-hexahydro-1,4-methanonaphthalen-5(1H)-one a No Expected Sensitization Induction Level (NESIL) of 5300 μg/cm2 for the skin sensitization endpoint. The photoirritation/photoallergenicity endpoints were evaluated based on data and ultraviolet/visible (UV/Vis) spectra; 4,4a,6,7,8,8a-hexahydro-1,4-methanonaphthalen-5(1H)-one is not photoirritating/photoallergenic. The environmental endpoints were evaluated; 4,4a,6,7,8,8a-hexahydro-1,4-methanonaphthalen-5(1H)-one was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use (VoU) in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.