RIFM fragrance ingredient safety assessment, 3,7-dimethyl-3,6-octadienal, CAS registry number 55722-59-3.

The existing information supports the use of this material as described in this safety assessment. 3,7-Dimethyl-3,6-octadienal was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog citral (CAS # 5392-40-5) show that 3,7-dimethyl-3,6-octadienal is not expected to be genotoxic and provided a calculated margin of exposure (MOE) >100 for the repeated dose toxicity and developmental and reproductive endpoints. Data from the read-across analog citronellal (CAS # 106-23-0) provided 3,7-dimethyl-3,6-octadienal a No Expected Sensitization Induction Level (NESIL) of 7000 μg/cm for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; 3,7-dimethyl-3,6-octadienal is not expected to be phototoxic/photoallergenic. The local respiratory toxicity endpoint was evaluated using the threshold of toxicological concern (TTC) for a Cramer Class I material, and the exposure to 3,7-dimethyl-3,6-octadienal is below the TTC (1.4 mg/day). The environmental endpoints were evaluated; 3,7-dimethyl-3,6-octadienal 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 in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.