A strategy for structuring and reporting a read-across prediction of toxicity.

Category formation, grouping and read across methods are broadly applicable in toxicological assessments and may be used to fill data gaps for chemical safety assessment and regulatory decisions. In order to facilitate a transparent and systematic approach to aid regulatory acceptance, a strategy to evaluate chemical category membership, to support the use of read-across predictions that may be used to fill data gaps for regulatory decisions is proposed. There are two major aspects of any read-across exercise, namely assessing similarity and uncertainty. While there can be an over-arching rationale for grouping organic substances based on molecular structure and chemical properties, these similarities alone are generally not sufficient to justify a read-across prediction. Further scientific justification is normally required to justify the chemical grouping, typically including considerations of bioavailability, metabolism and biological/mechanistic plausibility. Sources of uncertainty include a variety of elements which are typically divided into two main issues: the uncertainty associated firstly with the similarity justification and secondly the completeness of the read-across argument. This article focuses on chronic toxicity, whilst acknowledging the approaches are applicable to all endpoints. Templates, developed from work to prepare for the application of new toxicological data to read-across assessment, are presented. These templates act as proposals to assist in assessing similarity in the context of chemistry, toxicokinetics and toxicodynamics as well as to guide the systematic characterisation of uncertainty both in the context of the similarity rationale, the read across data and overall approach and conclusion. Lastly, a workflow for reporting a read-across prediction is suggested.

Mixture toxicity of SN2-reactive soft electrophiles: 3. Evaluation of ethyl α-halogenated acetates with α-halogenated acetonitriles.

Mixture toxicity for each of four ethyl α-halogenated acetates with each of three α-halogenated acetonitriles (xANs) was assessed. Inhibition of bioluminescence in Vibrio fischeri was measured after 15, 30, and 45 min of exposure. Concentration-response curves were developed for each chemical at each exposure duration and used to develop predicted concentration-response curves for the dose-addition and independence models of combined effect. Concentration-response curves for each mixture and each exposure duration were then evaluated against the predicted curves using three metrics per model: (1) EC50-based additivity quotient (AQ) or independence quotient (IQ) values; (2) mean AQ (mAQ) or mean IQ (mIQ) values, which were calculated by averaging the EC25, EC50, and EC75 AQ or IQ values; and (3) deviation values from additivity (DV-A) or independence (DV-I). Mixture toxicity for ethyl iodoacetate was dose-additive with each of the xANs at all exposure durations and was also often consistent with independence. The same was true for mixture toxicity of ethyl bromoacetate with each xAN. However, for the two more slowly reactive chemicals, ethyl chloroacetate (ECAC) and ethyl fluoroacetate (EFAC), mixture toxicity with each xAN only became consistent with dose-addition on increasing exposure duration. Consistency with independence for both ECAC and EFAC with the xANs was essentially limited to the EC50-IQ metric, thereby showing the utility of calculating the mean quotient (mAQ, mIQ) and deviation value (DV-A, DV-I) metrics. On review of these findings with those from the first two studies in the series, the results suggest that instances in which mixture toxicity was not consistent with dose-addition relate (1) to differences in the capability of the chemicals to form strong H-bonds with water; and (2) to differences in relative reactivity and time-dependent toxicity levels of the chemicals.

Update to RIFM fragrance ingredient safety assessment, 4-hexen-1-ol, 5-methyl-2-(1-methylethenyl)-, CAS registry number 58461-27-1.

4-Hexen-1-ol, 5-methyl-2-(1-methylethenyl)- was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, photoirritation/photoallergenicity, skin sensitization, and environmental safety. Data show that 4-hexen-1-ol, 5-methyl-2-(1-methylethenyl)- 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-hexen-1-ol, 5-methyl-2-(1-methylethenyl)- is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). Data from read-across analog 3-methylbut-3-en-1-ol (CAS # 763-32-6) show that there are no safety concerns for 4-hexen-1-ol, 5-methyl-2-(1-methylethenyl)- for skin sensitization under the current declared levels of use. The photoirritation/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; 4-hexen-1-ol, 5-methyl-2-(1-methylethenyl)- is not expected to be photoirritating/photoallergenic. The environmental endpoints were evaluated; 4-hexen-1-ol, 5-methyl-2-(1-methylethenyl)- 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.

RIFM fragrance ingredient safety assessment, 2,4,6-cycloheptatrien-1-one, 2-hydroxy-4-(1-methylethyl)-, CAS Registry Number 499-44-5.

The existing information supports the use of this material as described in this safety assessment. This material has not been fully evaluated for photoallergenic potential. 2,4,6-Cycloheptatrien-1-one, 2-hydroxy-4-(1-methylethyl)- was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, photoirritation/photoallergenicity, skin sensitization, and environmental safety. Data show that 2,4,6-cycloheptatrien-1-one, 2-hydroxy-4-(1-methylethyl)- 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 2,4,6-cycloheptatrien-1-one, 2-hydroxy-4-(1-methylethyl)- is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). The skin sensitization endpoint was completed using the Dermal Sensitization Threshold (DST) for reactive materials (64 µg/cm2); exposure is below the DST. Based on data, 2,4,6-cycloheptatrien-1-one, 2-hydroxy-4-(1-methylethyl)- is a photoirritant but is not a concern under the current declared use levels. 2,4,6-Cycloheptatrien-1-one, 2-hydroxy-4-(1-methylethyl)- was not evaluated for photoallergenicity. The environmental endpoints were evaluated; for the hazard assessment based on the screening data, 2,4,6-cycloheptatrien-1-one, 2-hydroxy-4-(1-methylethyl)- 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.

Update to RIFM fragrance ingredient safety assessment, 2,4-dimethylbenzyl acetate, CAS Registry Number 62346-96-7.

The MOE is greater than 100. Without adjustment for specific uncertainty factors related to inter-species and intra-species variation, the material exposure by inhalation at 0.0040 mg/day is deemed to be safe under the most conservative consumer exposure scenario.

RIFM fragrance ingredient safety assessment, 3-phenylpropyl acetate, CAS Registry Number 122-72-5.

Therefore, the phenethyl formate MOE for the fertility endpoint can be calculated by dividing the phenethyl alcohol NOAEL in mg/kg/day by the total systemic exposure to phenethyl formate, 1000/0.00062 or 1612903.

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, 5-hydroxy-7-decenoic acid δ-lactone, CAS Registry Number 25524-95-2.

The existing information supports the use of this material as described in this safety assessment. 5-Hydroxy-7-decenoic acid δ-lactone was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across material tetrahydro-6-(3-pentenyl)-2H-pyran-2-one (CAS # 32764-98-0) show that 5-hydroxy-7-decenoic acid δ-lactone is not expected to be 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 5-hydroxy-7-decenoic acid δ-lactone is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). Data show that there are no safety concerns for 5-hydroxy-7-decenoic acid δ-lactone for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; 5-hydroxy-7-decenoic acid δ-lactone is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 5-Hydroxy-7-decenoic acid δ-lactone 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, 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.

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.

Update to RIFM fragrance ingredient safety assessment, α-irone, CAS registry number 79-69-6.

In addition, the total systemic exposure to α-irone (1.1 µg/kg/day) is below the TTC (30 µg/kg/day; Kroes et al., 2007) for the repeated dose toxicity endpoint of a Cramer Class I material at the current level of use.

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, ß-caryophyllene, CAS Registry Number 87-44-5.

The existing information supports the use of this material as described in this safety assessment. ß-Caryophyllene was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that ß-caryophyllene is not genotoxic. Data on ß-caryophyllene provided a calculated Margin of Exposure (MOE) > 100 for the repeated dose toxicity and fertility endpoints. The developmental and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class I material, and the exposure to ß-caryophyllene is below the TTC (0.03 mg/kg/day and 1.4 mg/day, respectively. Data show that there are no safety concerns for ß-caryophyllene for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on data and ultraviolet/visible (UV/Vis) spectra; ß-caryophyllene is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; ß-caryophyllene 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.

The RIFM approach to evaluating Natural Complex Substances (NCS).

The Research Institute for Fragrance Materials, Inc. (RIFM) has evaluated safety data for fragrance materials for 55 years. The safety assessment of Natural Complex Substances (NCS) is similar to that of discrete fragrance materials; all of the same endpoints are evaluated. A series of decision trees, reflecting advances in risk assessment approaches of mixtures and toxicological methodologies, follows a tiered approach for each endpoint using a 4-step process with testing only as a last resort: 1) evaluate available data on NCS; 2) verify whether the Threshold of Toxicological Concern (TTC) can be applied; 3) verify whether the NCS risk assessment can be achieved on a component basis; and 4) determine whether data must be generated. Using in silico tools, RIFM examined NCS similarities based on the plant part, processing, and composition of materials across 81 plant families to address data gaps. Data generated from the Creme RIFM Aggregate Exposure Model for over 900 fragrance NCS demonstrate that dermal exposure is the primary route of human exposure for NCS fragrance uses. Over a third of materials are below the most conservative TTC limits. This process aims to provide a comprehensive Safety Assessment of NCS used as a fragrance ingredient.

RIFM fragrance ingredient safety assessment, phenethyl phenylacetate, CAS Registry Number 102-20-5.

The existing information supports the use of this material as described in this safety assessment. Phenethyl phenylacetate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that phenethyl phenylacetate is not genotoxic. Data provide a calculated MOE >100 for the repeated dose toxicity endpoint. Data on read-across analog benzyl benzoate (CAS # 120-51-4) provide an MOE >100 for the developmental toxicity endpoint. The fertility and local respiratory toxicity endpoints were evaluated using the TTC for a Cramer Class I material, and the exposure to phenethyl phenylacetate is below the TTC (0.03 mg/kg/day, and 1.4 mg/day, respectively). Data from analog benzyl phenylacetate (CAS # 102-16-9) show that there are no safety concerns for phenethyl phenylacetate for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on UV/Vis spectra; phenethyl phenylacetate is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; phenethyl phenylacetate was found not to be PBT as per the IFRA Environmental Standards and its risk quotients, based on its current volume of use in Europe and North America (i.e., PEC/PNEC), are <1.

RIFM fragrance ingredient safety assessment, tetrahydro-6-(3-pentenyl)-2H-pyran-2-one, CAS Registry Number 32764-98-0.

The existing information supports the use of this material as described in this safety assessment. Tetrahydro-6-(3-pentenyl)-2H-pyran-2-one was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that tetrahydro-6-(3-pentenyl)-2H-pyran-2-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 II material, and the exposure to tetrahydro-6-(3-pentenyl)-2H-pyran-2-one is below the TTC (0.009 mg/kg/day, 0.009 mg/kg/day, and 0.47 mg/day, respectively). Data and read-across to 5-hydroxy-7-decenoic acid δ-lactone (CAS # 25,524-95-2) show that there are no safety concerns for tetrahydro-6-(3-pentenyl)-2H-pyran-2-one for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on data and ultraviolet/visible (UV/Vis) spectra; tetrahydro-6-(3-pentenyl)-2H-pyran-2-one is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; tetrahydro-6-(3-pentenyl)-2H-pyran-2-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 in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.

RIFM fragrance ingredient safety assessment, 6,6-dimethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde, CAS Registry Number 33885-51-7.

No treatment-related effects at the low and mid doses were observed in gestation, viability and lactation indices, duration of gestation, parturition, sex ratio, maternal care, litter size, and early postnatal pup development consisting of mortality, clinical signs, anogenital distance, areola/nipple retention, T4 thyroid hormone levels, or macroscopic examination. However, the number of litters (N = 5) at the high dose was considered too low for toxicological evaluation. Thus, based on insufficient data at 120 mg/kg/day, the NOAEL for this study was considered to be 60 mg/kg/day (RIFM, 2020d).

RIFM fragrance ingredient safety assessment, cis-3-hexenyl methyl carbonate, CAS Registry Number 67633-96-9.

The following paper presents the method of determination of the percolation threshold in cement composites with expanded graphite by impedance spectroscopy. Most of the applications of cement composites with conductive additives require exceeding the percolation threshold. The ionic conductivity of cement matrix below the percolation threshold has a major impact on the conductivity of the composite, as a result, it significantly hinders the exploitation of these composites. The electric properties of cement composites with expanded graphite were evaluated by DC measurements and impedance spectroscopy (IS). Based on Nyquist plots, two equivalent circuits were adopted for the composites. Next, the values of capacitance and inductance of cement composites with expanded graphite were calculated from the fitted equivalent circuits. The analysis of the results shows that the percolation threshold occurs when the reactance of the composite changes from captative to inductive. Comparison between the values of percolation threshold obtained from DC measurements and IS shows that the method is effective for cement composites with conductive additives.

RIFM fragrance ingredient safety assessment, 5,8-methano-2H-1-benzopyran, 6(or 7)-ethylideneoctahydro-, [4aR,5S,8S,8aS(or 4aR,5R,8S,8aR)]-rel-, CAS Registry Number 943723-15-7.

The existing information supports the use of this material as described in this safety assessment. 5,8-Methano-2H-1-benzopyran, 6(or 7)-ethylideneoctahydro-, [4aR,5S,8S,8aS(or 4aR,5R,8S,8aR)]-rel- was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog 5,8-methano-2H-1-benzopyran-2-one, 6- ethylideneoctahydro- (CAS # 69486-14-2) show that 5,8-methano-2H-1-benzopyran, 6(or 7)-ethylideneoctahydro-, [4aR,5S,8S,8aS(or 4aR,5R,8S,8aR)]-rel- is not expected to be genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the TTC for a Cramer Class III material, and the exposure to 5,8-methano-2H-1-benzopyran, 6(or 7)-ethylideneoctahydro-, [4aR,5S,8S,8aS(or 4aR,5R,8S,8aR)]-rel- is below the TTC (0.0015 mg/kg/day, 0.0015 mg/kg/day, and 0.47 mg/day, respectively). Data provided 5,8-methano-2H-1-benzopyran, 6(or 7)-ethylideneoctahydro-, [4aR,5S,8S,8aS(or 4aR,5R,8S,8aR)]-rel- a NESIL of 8200 µg/cm2 for the skin sensitization endpoint. The phototoxicity/photoallergenicity endpoints were evaluated based on human study data and UV/Vis spectra; 5,8-methano-2H-1-benzopyran, 6(or 7)-ethylideneoctahydro-, [4aR,5S,8S,8aS(or 4aR,5R,8S,8aR)]-rel- is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 5,8-methano-2H-1-benzopyran, 6(or 7)-ethylideneoctahydro-, [4aR,5S,8S,8aS(or 4aR,5R,8S,8aR)]-rel- was found not to be PBT as per the IFRA Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., PEC/PNEC), are <1.