RIFM fragrance ingredient safety assessment, (-)-(R)-α-phellandrene, CAS Registry Number 4221-98-1

Therefore, the (-)-(R)-α-phellandrene MOE for the repeated dose toxicity endpoint can be calculated by dividing the (-)-(R)-α-phellandrene NOAEL in mg/kg/day by the total systemic exposure to (-)-(R)-α-phellandrene, 8.33/0.00040, or 20825.

RIFM fragrance ingredient safety assessment, 2,6-nonadienenitrile, CAS Registry Number 67019-89-0

The existing information supports the use of this material as described in this safety assessment. 2,6-Nonadienenitrile was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 2,6-nonadienenitrile is not genotoxic. Data on read-across analog E- and Z-2(+3),12-tridecadiennitrile (CAS # 124071-40-5) provided 2,6-nonadienenitrile 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 2,6-nonadienenitrile is below the TTC (0.0015 mg/kg/day and 0.47 mg/day, respectively). Data show that there are no safety concerns for 2,6-nonadienenitrile for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; 2,6-nonadienenitrile is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 2,6-nonadienenitrile 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.

Identifying a reference list of respiratory sensitizers for the evaluation of novel approaches to study respiratory sensitization

The induction of immunological responses that trigger bio-physiological symptoms in the respiratory tract following repeated exposure to a substance, is known as respiratory sensitization. The inducing compound is known as a respiratory sensitizer. While respiratory sensitization by high molecular weight (HMW) materials is recognized and extensively studied, much less information is available regarding low molecular weight (LMW) materials as respiratory sensitizers. Variability of symptoms presented in humans from such exposures, limited availability of (and access to) documented reports, and the absence of standardized and validated test models, hinders the identification of true respiratory sensitizers. This review aims to sort suspected LMW respiratory sensitizers based on available compelling, reasonable, inadequate, or questionable evidence in humans from occupational exposures and use this information to compose a reference list of reported chemical respiratory sensitizers for scientific research purposes. A list of 97 reported respiratory sensitizers was generated from six sources, and 52 LMW organic chemicals were identified, reviewed, and assigned to the four evidence categories. Less than 10 chemicals were confirmed with compelling evidence for induction of respiratory sensitization in humans from occupational exposures. Here, we propose the reference list for developing novel research on respiratory sensitization.