Expected Sensitization Induction Level Research Articles

GARDskin dose-response assay and its application in conducting Quantitative Risk Assessment (QRA) for fragrance materials using a Next Generation Risk Assessment (NGRA) framework

Development of New Approach Methodologies (NAMs) capable of providing a No Expected Sensitization Induction Level (NESIL) value remains a high priority for the fragrance industry for conducting a Quantitative Risk Assesment (QRA) to evaluate dermal sensitization. The in vitro GARDskin assay was recently adopted by the OECD (TG 442E) for the hazard identification of skin sensitizers. Continuous potency predictions are derived using a modified protocol that incorporates dose-response measurements. Linear regression models have been developed to predict human NESIL values. The aim of the study was to evaluate the precision and reproducibility of the continuous potency predictions from the GARDskin Dose-Response (DR) assay and its application in conducting QRA for fragrance materials using a Next Generation Risk Assessment (NGRA) framework. Results indicated that the GARDskin Dose-Response model predicted human NESIL values with a good degree of concordance with published NESIL values, which were also reproducible in 3 separate experiments. Using Isocyclocitral as an example, a QRA was conducted to determine its safe use levels in different consumer product types using a NGRA framework. This study represents a major step towards the establishment of the assay to derive NESIL values for conducting QRA evaluations for fragrance materials using a NGRA framework.

Assessing the risk of induction of skin sensitization to plant protection products: A quantitative approach

Exposure to skin sensitizers is common and regulated in many industry sectors. For cosmetics, a risk-based approach has been implemented, focused on preventing the induction of sensitization. First, a No Expected Sensitization Induction Level (NESIL) is derived, then modified by Sensitization Assessment Factors (SAFs) to derive an Acceptable Exposure Level (AEL). The AEL is used in risk assessment, being compared with an estimated exposure dose, specific to the exposure scenario. Since in Europe there is increased concern regarding exposure towards potentially sensitizing pesticides via spray drift, we explore how existing practice can be modified to allow Quantitative Risk Assessment (QRA) of pesticides for bystanders and residents. NESIL derivation by the Local Lymph Node Assay (LLNA), the globally required in vivo assay for this endpoint, is reviewed alongside consideration of appropriate SAFs. Using a case study, the principle that the NESIL in μg/cm2 can be derived by multiplying LLNA EC3% figure by a factor of 250 is adopted. The NESIL is then reduced by an overall SAF of 25 to establish an exposure level below which there is minimal bystander and resident risk. Whilst this paper focuses on European risk assessment and management, the approach is generic and universally applicable.

RIFM fragrance ingredient safety assessment, 3-Cyclohexene-1-carboxaldehyde, 1-ethenyl-, CAS Registry Number 1049017-63-1.

The existing information supports the use of this material as described in this safety assessment. 3-Cyclohexene-1-carboxaldehyde, 1-ethenyl- was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 3-cyclohexene-1-carboxaldehyde, 1-ethenyl- is not genotoxic. Data on 3-cyclohexene-1-carboxaldehyde, 1-ethenyl- 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 I material, and the exposure to 3-cyclohexene-1-carboxaldehyde, 1-ethenyl-is below the TTC (0.03mg/kg/day and 1.4mg/day, respectively). Data provided 3-cyclohexene-1-carboxaldehyde, 1-ethenyl- a No Expected Sensitization Induction Level (NESIL) of 1000μg/cm2 for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; 3-cyclohexene-1-carboxaldehyde, 1-ethenyl- is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 3-cyclohexene-1-carboxaldehyde, 1-ethenyl- 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.

RIFM fragrance ingredient safety assessment, geraniol, CAS registry number 106-24-1.

The existing information supports the use of this material as described in this safety assessment. Geraniol was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that geraniol is not genotoxic. Data on geraniol provide a calculated Margin of Exposure (MOE)>100 for the repeated dose toxicity and reproductive toxicity endpoints. Data provided geraniol a No Expected Sensitization Induction Level (NESIL) of 11000μg/cm2 for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; geraniol 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 geraniol is below the TTC (1.4mg/day). The environmental endpoints were evaluated; geraniol 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.

RIFM fragrance ingredient safety assessment, l-carvone, CAS Registry Number 6485-40-1

l-Carvone was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that l-carvone is not genotoxic and provided a No Expected Sensitization Induction Level (NESIL) of 2600 μg/cm2 for the skin sensitization endpoint. Data on l-carvone provided a calculated Margin of Exposure (MOE) >100 for the repeated dose toxicity and reproductive toxicity endpoints. The phototoxicity/photoallergenicity endpoint was completed based on data and ultraviolet/visible (UV/Vis) spectra; l-carvone is not phototoxic/photoallergenic. The local respiratory toxicity endpoint was evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class II material (0.47 mg/day); the exposure to l-carvone is below the TTC. The environmental endpoints were evaluated; l-carvone 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.

RIFM fragrance ingredient safety assessment, octyl isobutyrate, CAS Registry Number 109-15-9

The existing information supports the use of this material as described in this safety assessment. Octyl isobutyrate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog hexyl isobutyrate (CAS # 2349-07-7) show that octyl isobutyrate is not expected to be genotoxic. Data on analog propyl (2S)-2-(1,1-dimethylpropoxy)-propanoate (CAS # 319002-92-1) provide a calculated Margin of Exposure (MOE) > 100 for the repeated dose and reproductive toxicity endpoints. Data from analog hexyl 2-methylbutyrate (CAS # 10032-15-2) provided octyl isobutyrate a No Expected Sensitization Induction Level (NESIL) of 7000 μg/cm2 for the skin sensitization endpoint. Octyl isobutyrate is not expected to be phototoxic/photoallergenic based on ultraviolet/visible (UV/Vis) spectra. The local respiratory toxicity endpoint was evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class I material; exposure to is below the TTC (1.4 mg/day). The environmental endpoints were evaluated; octyl isobutyrate 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.

RIFM fragrance ingredient safety assessment, 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal, CAS Registry Number 65405-84-7

The existing information supports the use of this material as described in this safety assessment. 4-(2,6,6-Trimethyl-2-cyclohexen)-2-methylbutanal was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal 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 I material, and the exposure to 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). Data provided 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal a No Expected Sensitization Induction Level (NESIL) of 1100 μg/cm2 for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on data and ultraviolet/visible (UV/Vis) spectra; 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 4-(2,6,6-trimethyl-2-cyclohexen)-2-methylbutanal 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.

Derivation of the no expected sensitization induction level for dermal quantitative risk assessment of fragrance ingredients using a weight of evidence approach

Some fragrance ingredients may have the potential to induce skin sensitization in humans but can still be safely formulated into consumer products. Quantitative Risk Assessment (QRA) for dermal sensitization is required to determine safe levels at which potential skin sensitizers can be incorporated into consumer products. The no expected sensitization induction level or NESIL is the point of departure for the dermal QRA. Sensitization assessment factors are applied to the NESIL to determine acceptable exposure levels at which no skin sensitization induction would be expected in the general population. This paper details the key steps involved in deriving a weight of evidence (WoE) NESIL for a given fragrance ingredient using all existing data, including in vivo, in vitro, and in silico. Read-across can be used to derive a NESIL for a group of structurally similar materials when data are insufficient. When sufficient target and read-across data are lacking, exposure waiving threshold (the DST) may be used. We outline the process as it currently stands at the Research Institute for Fragrance Materials Inc. (RIFM) and provide examples, but it is dynamic and is bound to change with evolving science as new approach methodologies (NAMs) are actively incorporated.

RIFM fragrance ingredient safety assessment, cis-3-hexenyl tiglate, CAS Registry Number 67883-79-8

The existing information supports the use of this material as described in this safety assessment. cis-3-Hexenyl tiglate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analogs 2-methyl-trans-2-butenoic acid (CAS # 80-59-1) and cis-3-hexenol (CAS # 928-96-1) show that cis-3-hexenyl tiglate is not expected to be genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the Threshold for Toxicological Concern (TTC) for a Cramer Class I material; exposure to cis-3-hexenyl tiglate is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day and 1.4 mg/day, respectively). Data from analog 2-hexenoic acid, 2-methyl-, methyl ester, (2E)- (CAS # 16493-96-2) provided cis-3-hexenyl tiglate a No Expected Sensitization Induction Level (NESIL) of 1100 μg/cm2 for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; cis-3-hexenyl tiglate is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; cis-3-hexenyl tiglate 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.

Derivation of the no expected sensitization induction level for dermal quantitative risk assessment by the Research Institute for Fragrance Materials

Derivation of the no expected sensitization induction level for dermal quantitative risk assessment by the Research Institute for Fragrance Materials

RIFM fragrance ingredient safety assessment, 4,8-decadienal, (4Z,8Z)-, CAS Registry Number 1958027-35-4

Summary: The existing information supports the use of this material as described in this safety assessment.4,8-Decadienal, (4Z,8Z)- was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analogs 4,7-decadienal (CAS # 934534-30-2) and nona-2-trans-6-cis-dienal (CAS # 557-48-2) show that 4,8-decadienal, (4Z,8Z)- is not expected to be genotoxic. Data on analog 10-undecenal (CAS # 112-45-8) provide a calculated Margin of Exposure (MOE) > 100 for the repeated dose toxicity and fertility endpoints and a No Expected Sensitization Induction Level (NESIL) of 1700 μg/cm2 for the skin sensitization endpoint. The developmental toxicity and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for Cramer Class I materials; exposure is below the TTC (0.03 mg/kg/day and 1.4 mg/day, respectively). The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; 4,8-decadienal, (4Z,8Z)- is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 4,8-decadienal, (4Z,8Z)- was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards. 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.

RIFM fragrance ingredient safety assessment, p-tolualdehyde, CAS Registry Number 104-87-0

The existing information supports the use of this material as described in this safety assessment.p-Tolualdehyde was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity, skin sensitization potential, and environmental safety. Data from read-across analog benzaldehyde (CAS # 100-52-7) show that p-tolualdehyde is not expected to be genotoxic. Data from read-across analog cuminaldehyde (CAS # 122-03-2) provided p-tolualdehyde a No Expected Sensitization Induction Level (NESIL) of 1100 μg/cm2 for the skin sensitization endpoint. The repeated dose toxicity, developmental and reproductive toxicity, and local respiratory toxicity endpoints were completed using the threshold of toxicological concern (TTC) for a Cramer Class I material, and the exposure to p-tolualdehyde is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). The phototoxicity/photoallergenicity endpoints were evaluated based on data from read-across analog 4-ethylbenzaldehyde (CAS # 4748-78-1); p-tolualdehyde is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; p-tolualdehyde 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.

RIFM fragrance ingredient safety assessment, 4-ethylbenzaldehyde, CAS Registry Number 4748-78-1

The existing informationsupportsthe use of this material as described in this safety assessment. 4-ethylbenzaldehyde was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity, skin sensitization, and environmental safety. Data on the read-across analog benzaldehyde (CAS # 100-52-7) show that 4-ethylbenzaldehyde is not expected to be genotoxic and provide a calculated margin of exposure (MOE) >100 for the repeated dose toxicity endpoint. Data on read-across analog 3,4-dimethylbenzaldehyde (CAS # 5973-71-7) provide a calculated MOE >100 for the developmental and reproductive toxicity endpoints. Data on read-across analog cuminaldehyde (CAS # 122-03-2) provided 4-ethylbenzaldehyde a No Expected Sensitization Induction Level (NESIL) of 1100 μg/cm². The local respiratory toxicity endpoint was evaluated using the threshold of toxicological concern (TTC) for a Cramer Class I material; exposure is below the TTC (1.4 mg/day). The phototoxicity/photoallergenicity endpoints were evaluated based on data; 4-ethylbenzaldehyde is not phototoxic/photoallergenic. The environmental endpoints were evaluated; 4-ethylbenzaldehyde 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.

RIFM fragrance ingredient safety assessment, 2-phenylpropionaldehyde, CAS Registry Number 93-53-8

Summary: The existing information supports the use of this material as described in this safety assessment.2-Phenylpropionaldehyde was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data on read-across analogs 3-phenylbutanal (CAS # 16251-77-7) and isopropylphenylbutanal (CAS # 125109-85-5) show that this material is not expected to be genotoxic. Data from the target material provide a calculated margin of exposure (MOE) >100 for the repeated dose toxicity endpoint and a No Expected Sensitization Induction Level (NESIL) of 380 μg/cm2 for the skin sensitization endpoint. The developmental and reproductive toxicity and the local respiratory toxicity endpoints were completed using the threshold of toxicological concern (TTC) for a Cramer Class I material (0.03 mg/kg/day and 1.4 mg/day, respectively). The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; 2-phenylpropionaldehyde is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 2-phenylpropionaldehyde 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.

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

Summary: 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/cm2 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.

RIFM fragrance ingredient safety assessment, phenylacetaldehyde, CAS Registry Number 122-78-1.

The existing information supports the use of this material as described in this safety assessment.The material (phenylacetaldehyde) was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity, skin sensitization, and environmental safety. Data show that phenylacetaldehyde is not genotoxic and provide a calculated margin of exposure (MOE) > 100 for the repeated dose and developmental and reproductive toxicity endpoints. Data from phenylacetaldehyde provided a No Expected Sensitization Induction Level (NESIL) of 590 μg/cm2 for the skin sensitization endpoint. The local respiratory toxicity endpoint was completed using the threshold of toxicological concern (TTC) for a Cramer Class I material, and the exposure to phenylacetaldehyde was below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). The phototoxicity/photoallergenicity endpoint was completed based on data and ultraviolet (UV) spectra; phenylacetaldehyde is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; phenylacetaldehyde was not found 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.

RIFM fragrance ingredient safety assessment, 3-(m-tert-butylphenyl)-2-methylpropionaldehyde, CAS Registry Number 62518-65-4

The existing information supports the use of 3-(m-tert-butylphenyl)-2-methylpropionaldehyde as described in this safety assessment. 3-(m-tert-Butylphenyl)-2-methylpropionaldehyde 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 p-t-butyl-α-methylhydrocinnamic aldehyde (CAS # 80-54-6) show that 3-(m-tert-butylphenyl)-2-methylpropionaldehyde is not expected to be genotoxic. Data on 3-(m-tert-butylphenyl)-2-methylpropionaldehyde provide a calculated margin of exposure (MOE) >100 for the repeated dose toxicity and developmental and reproductive toxicity endpoints. Data from read-across analog p-t-butyl-α-methylhydrocinnamic aldehyde (CAS # 80-54-6) provided 3-(m-tert-butylphenyl)-2-methylpropionaldehyde a No Expected Sensitization Induction Level (NESIL) of 4100 μg/cm2 for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; 3-(m-tert-butylphenyl)-2-methylpropionaldehyde 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; the exposure to 3-(m-tert-butylphenyl)-2-methylpropionaldehyde is below the TTC (1.4 mg/day). The environmental endpoints were evaluated; 3-(m-tert-butylphenyl)-2-methylpropionaldehyde 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.

RIFM fragrance ingredient safety assessment, cinnamyl alcohol, CAS Registry Number 104-54-1

The existing information supports the use of this material as described in this safety assessment. Cinnamyl alcohol was evaluated for genotoxicity, repeated dose toxicity, developmental toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity, skin sensitization, and environmental safety. Data show that cinnamyl alcohol is not genotoxic. Data on read-across analog cinnamaldehyde (CAS # 104-55-2) provide a calculated margin of exposure (MOE) >100 for the repeated dose and local respiratory toxicity endpoints. The developmental and reproductive toxicity endpoint was evaluated using the threshold of toxicological concern (TTC) for a Cramer Class I material, and the exposure to cinnamyl alcohol is below the TTC (0.03 mg/kg/day). Data provided a No Expected Sensitization Induction Level (NESIL) of 2900 μg/cm2 for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on UV spectra; cinnamyl alcohol is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; cinnamyl alcohol 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.

Adjustment of a no expected sensitization induction level derived from Bayesian network integrated testing strategy for skin sensitization risk assessment.

Skin sensitization is a key adverse effect to be addressed during hazard identification and risk assessment of chemicals, because it is the first step in the development of allergic contact dermatitis. Multiple non-animal testing strategies incorporating in vitro tests and in silico tools have achieved good predictivities when compared with murine local lymph node assay (LLNA). The binary test battery of KeratinoSensTM and h-CLAT could be used to classify non-sensitizers as the first part of bottom-up approach. However, the quantitative risk assessment for sensitizing chemicals requires a No Expected Sensitization Induction Level (NESIL), the dose not expected to induce skin sensitization in humans. We used Bayesian network integrated testing strategy (BN ITS-3) for chemical potency classification. BN ITS-3 predictions were performed without a pre-processing step (selecting data from their physic-chemical applicability domains) or post-processing step (Michael acceptor chemistry correction), neither of which necessarily improve prediction accuracy. For chemicals within newly defined applicability domain, all under-predictions fell within one potency class when compared with LLNA results, indicating no chemicals that were incorrectly classified by more than one class. Considering the potential under-prediction by one class, a worst case value to each class from BN ITS-3 was used to derive a NESIL. When in vivo and human data from suitable analogs cannot be used to estimate the uncertainty, adjusting the NESIL derived from BN ITS-3 may help perform skin sensitization risk assessment. The overall workflow for risk assessment was demonstrated by incorporating the binary test battery of KeratinoSensTM and h-CLAT.

The dermal sensitization threshold (DST) approach for mixtures evaluated as negative in in vitro test methods; mixture DST.

Cosmetic ingredients often comprise complex mixtures, such as botanical extracts, which may contain skin sensitizing constituents. In our previous study for the sensitivity of the evaluations of skin sensitizing constituents in mixtures using the binary in vitro test battery with KeratinoSensTM and h-CLAT, some sensitizers showed higher detection limits in in vitro test methods than in murine local lymph node assays (LLNA). Thus, to minimize the uncertainty associated with decreased sensitivity for these sensitizers, a risk assessment strategy was developed for mixtures with negative results from the binary test battery. Assuming that the no expected sensitization induction level of mixtures (mixture NESIL) can be derived for mixtures with negative in vitro test results, we assessed 146 sensitizers with in vitro and LLNA data according to the assumption of indeterminate constituents in mixtures. Finally, we calculated 95th percentile probabilities of mixture NESILs and derived dermal sensitization thresholds for mixtures (mixture DST) with negative in vitro test results of 6010 μg/cm2. Feasibility studies indicated that this approach was practical for risk assessments of products in the cosmetic industry. This approach would be a novel risk assessment strategy for incorporating the DST approach and information from in vitro test methods.