3,3-dimethyl-8,9-dinorbornan-2-one

Endpoint summary

Description of key information

Short term toxicity to aq. invertebrates:

Based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on daphnia magna was predicted for 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5). Based on the intoxication of test organism the EC50 value was estimated to be 157 mg/l when 3,3-Dimethyl-8,9- dinorbornan-2-one exposed to daphnia magna for 48 hrs. Based on this value it can be concluded that the substance 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) is considered to be nontoxic to aquatic environment and cannot classified as per the criteria mentioned in CLP regulation.    

Toxicity to aq. algae and cyanobacteria:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the eight closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5). Based on the growth rate inhibition of algae, the EC50 value was estimated to be132.69 mg/l when 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) exposed to Pseudokirchneriella subcapitatafor 72hrs. Based on this value it can be concluded that the substance 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) is considered be nontoxic to aquatic environment and cannot be classified as per the criteria mentioned in CLP regulation.    

Additional information

Summarized result for the determination of nature of chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) on the growth and other biological and physical activity of aquatic invertebrates, algae and cyanobacteria when chemical comes in contact with test organisms, by considering the data for target as well as structurally and functionally similar read across chemicals which are as follows: 

 

Short term toxicity to aq. invertebrates:

Based on the various predicted data for the target chemical and experimental data for structurally and functionally similar read across chemicals study have been reviewed to determine the toxic nature of target chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) on the mobility of aquatic invertebrates. The studies are as mentioned below:  

 

In the first prediction for the target chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on daphnia magna was predicted for 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5). Based on the intoxication of test organism the EC50 value was estimated to be 157 mg/l when 3,3-Dimethyl-8,9- dinorbornan-2-one exposed to daphnia magna for 48 hrs. Based on this value it can be concluded that the substance 3,3-Dimethyl- 8,9-dinorbornan-2-one (1195-79-5) is considered to be nontoxic to aquatic environment and cannot classified as per the criteria mentioned in CLP regulation.    

 

Similarly in the second predicted weight of evidence for the 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) based on the average value of both models ( Leadscope Enterprise model and SciMatics SciQSAR model), the result were predicted in Battery model. Based on the Danish (Q)SAR Database, the 48 hours EC50 was estimated to be 148.75 mg/l on Daphnia Magna for substance 3,3-Dimethyl-8,9-dinorbornan-2-one with immobilization effects. Thus based on this value it can be concluded that the substance 3,3-Dimethyl-8,9-dinorbornan-2-one is nontoxic and cannot be classified as per the criteria of CLP regulation.

 

First predicted study was supported by the third experimental weight of evidence study for the read across chemical (470-82-6) from authoritative database j-check 2017. Aim of this study was to determine the acute Immobilization of (Cineole) 2-Oxabicyclo 2,2,2 octane, 1,3,3-trimethyl- to Daphnia magna for the exposure period of 48 hrs. Test conducted according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Analytical monitoring was also done using the GC were the Frequency of analysis was at the start of exposure and the end of exposure. Test solutions were prepared by mixing a stock solution of the test substance, which was prepared by mixing and stirring the test substance and water. Test performed at different concentrations 350, 230, 160, 104, 69 mg/L (geometric ratio 1.5), control. Test vessel filled with 400 mL/ concentration (100 mL/vessel) contain 20 daphnia per concentration (5 / vessel). Experiment repeated 4 times with the same condition. Based on the immobility of test organism daphnia magna due to the direct contact with the chemical (Cineole) 2-Oxabicyclo 2,2,2 octane, 1,3,3-trimethyl- for 48 hrs, the effect concentration was 200 mg/l with the 95 % CI of 180 - 230 mg/L. Thus on the basis of EC50, chemical was consider as nontoxic and not classified as toxic as per the CLP classification criteria.

 

Similarly in the fourth weight of evidence study for another read across chemical (540-88-5) from authoritative databases (HSDB and ECOTOX database) supports the nature of chemical. Short term toxicity study was carried out for determination of the nature of chemical tert-butyl acetate on the growth of aquatic invertebrates. Test conducted under the static system for the total exposure period of 24 hrs. <=24 h old daphnia magna were used in the study. Based on the intoxication (Measured by observing the immobility) of daphnia magna by the exposure of chemical tert-butyl acetate, the LC50 was determine to be 4730 mg/l. Based on the LC50 chemical was concluded as nontoxic and not classified as per the CLP classification criteria.

 

Based on the predicted data for the target chemical (from OECD QSAR 2018 and Danish QSAR) and for the read across chemical from authoritative databases (j-check, HSDB and ECOTOX database), it can be concluded that the substance 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) is considered to be not toxic to aquatic environment (aquatic invertebrates) and cannot be classified as toxic as per the criteria mentioned in CLP regulation.  

 

Toxicity to aq. algae and cyanobacteria:

Based on the various predicted data for the target chemical and experimental data for structurally and functionally similar read across chemicals study have been reviewed to determine the toxic nature of target chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) on the growth of aquatic algae. The studies are as mentioned below:   

 

In the first prediction for the target chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the eight closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5). Based on the growth rate inhibition of algae, the EC50 value was estimated to be132.69 mg/l when 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) exposed to Pseudokirchneriella subcapitata for 72hrs. Based on this value it can be concluded that the substance 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) is considered be nontoxic to aquatic environment and cannot be classified as per the criteria mentioned in CLP regulation.    

 

First predicted study was supported by the second experimental weight of evidence study for the read across chemical (1074-95-9) from lab report 2017. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance (±)-menthone according to OECD Guideline 201. The stock solution (150 mg/L) was prepared by dissolving colourless liquid in OECD growth medium. The solution was kept in ultrasonic bath for 20 min. It was not possible to prepare homogenous solution of higher concentration. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture and tested at the concentrations 0, 30, 45, 67, 100 and 150 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (EC50) for the test substance, (±)-menthone, in Desmodesmus subspicatus was determined to be 172.9 mg/L. This value indicates that the substance is likely to be non-hazardous to aquatic algae and can be considered as not classified as per the CLP criteria.

 

Similarly in the third study for the read across chemical (470-82-6) from authoritative database j-check 2017 having aim to determine the Growth Inhibition Test of (Cineole) 2-Oxabicyclo 2,2,2 octane, 1,3,3-trimethyl- to Alga (Pseudokirchneriella subcapitata) for the exposure period of 3 days. Test conducted according to OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test). Analytical monitoring was also done using the GC were the Frequency of analysis was at the start of exposure, after 4 hours from start of exposure, and at the end of exposure. Test solutions were prepared by mixing a stock solution of the test substance, which was prepared by adding and stirring the substance under the water surface of the Erlenmeyer flask filled with medium. Test performed on green algae Pseudokirchneriella subcapitata. Test was conducted at the different concentrations 500, 160, 50, 16, 5.0 mg/L (geometric ratio; square root of 10), control. Based on the growth rate inhibition of test organism Pseudokirchneriella subcapitata due to the direct contact with the chemical (Cineole) 2-Oxabicyclo 2,2,2 octane, 1,3,3-trimethyl- for 3 days, the effect concentration EC50 was 250 mg/l with the 95 % CL was 220 - 270 mg/L. and the NOEC was observed at the 16 mg/l. Thus on the basis of EC50, chemical was consider as nontoxic and not classified as toxic as per the CLP classification criteria.

 

Similarly in the fourth weight of evidence study for another read across chemical (540-88-5) from authoritative databases (HSDB and ECOTOX database) supports the nature of chemical. Toxicity study was carried out for determination of the nature of chemical tert-butyl acetate on the growth of aquatic algae and cyanobacteria. Test conducted under the static system for the total exposure period of 24 hrs. Based on the effect on Physiology and Assimilation efficiency of Chlorococcales (Green Algae Order), by the chemical tert-butyl acetate, the EC50 was determine at 1300 mg/l. Thus on the EC50 chemical tert-butyl acetate was concluded as nontoxic and not classified as per the CLP classification criteria. 

 

Based on the predicted data for the target chemical (from OECD QSAR 2018) and for the read across chemical from Lab report 2017 and authoritative databases (j-check, HSDB and ECOTOX database), it can be and concluded that the substance 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) is considered to be not toxic to aquatic environment (aquatic algae and cyanobacteria) and cannot be classified as toxic as per the criteria mentioned in CLP regulation.  

 

Thus on the basis of overall studies it can be concluded that 3,3-Dimethyl-8,9-dinorbornan-2-one (1195-79-5) is not toxic to aquatic environment and cannot be classified as toxic as per the criteria mentioned in CLP regulation.