RIFM fragrance ingredient safety assessment, 1-(2-methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol, CAS Registry Number 526218-21-3

The existing information supports the use of this material as described in this safety assessment. 1-(2-Methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 1-(2-methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol is not genotoxic. Data on 1-(2-methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol provide a calculated margin of exposure (MOE)  100 for the repeated dose toxicity endpoint. The 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 1-(2-methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol is below the TTC (0.0015 mg/kg/day and 0.47 mg/day, respectively). Data show that there are no safety concerns for 1-(2-methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; 1-(2-methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; for the hazard assessment based on the screening data, 1-(2-methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol is not persistent, bioaccumulative, and toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards. For the risk assessment, 1-(2-methylprop-2-enoloxy)-2,2,4-trimethylpentan-3-ol was not able to be risk screened as there were no reported volumes of use for either North America or Europe in the 2015 IFRA Survey.