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

Endpoint summary

Description of key information

Biodegradation in water

Biodegradation study was conducted for evaluating the percentage biodegradability of test substance 3,3-Dimethyl-8,9-dinorbornan-2-one (CAS no. 1195-79-5) (P. J. Chapman, et. al; 1965). Corynebacterium spp. (Bacteria), an organism which grows at the expense of either (+)- or (-)- camphor was used as a test inoculum for the study. Corynebacterium sp., strain T1, was inoculated from stock culture slants into 100 ml sterile nutrient broth (Difco; 8.0 g/liter) and grown at 30°C with shaking for 24 hours. Then, 10 ml portions were used to inoculate the test vessel containing the test chemical 3,3-Dimethyl-8,9-dinorbornan-2-one. Ten ml portions were used to inoculate six 2 liter Erlenmeyer flasks each containing 400 ml of sterile broth. After 24 hours incubation 2.4 g3,3-Dimethyl-8,9-dinorbornan-2-onein N,N,-dimethyl formamide (0.25 g/ml) was equally divided among all six flasks and incubation continued for a further 24 hours. The cells were then centrifuged and the clear neutral supernatant extracted 3 times with 0.5 vol. diethyl ether. The ether solution, after drying over anhydrous Na2SO4, was taken to dryness and 1.12 g of pale yellow crystalline solid obtained. When crystallized from light petroleum (b.p. range 60-68°C) at -72°C, the material had m.p. 73-75°C, λ^CHCl3_max 5.48µ (Found: C, 70.82; H 9.49. C10H16O2 requires C, 71.4; H, 9.52). Thin layer chromatography on silica gel G Drinkmann with ether-light petroleum (40:60, v/v) as solvent, revealed a single component reacting with alkaline hydroxylamine and detectable as its purple ferric hydroxamate. Gas chromatography on a stationary phase of 5% silicone gum rubber SE-30 at 150°C gave only a single peak but on 5% butanediol succinate polyester at 150°C a second component, approximately 10% of the total peak area, was distinguishable. A mixture of authentic 1,2- and 2,3-fencholides, obtained by the Baeyer-Villiger oxidation of 3,3-Dimethyl-8,9-dinorbornan-2-one (fenchone) with peracetic acid, showed essentially the same chromatographic properties as the biologically derived material. It will be noted that the major component corresponds to the 1,2-fencholide.Thus, based on this, 3,3-Dimethyl-8,9-dinorbornan-2-one is considered to be biodegradable in nature.

Bioaccumulation: aquatic / sediment

BCFBAF model (v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical 3,3 -Dimethyl-8,9 -dinorbornan-2 -one (CAS No. 1195 -79 -5). The bioconcentration factor (BCF) of 3,3-Dimethyl-8,9-dinorbornan-2-one was estimated to be 97.61 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical 3,3-Dimethyl-8,9-dinorbornan-2-one is not expected to bioaccumulate in the food chain.

Adsorption / desorption

Adsorption study was conducted at a temperature of 20°C for evaluating the adsorption capacity of test chemical Disodium 3,3-Dimethyl-8,9-dinorbornan-2-one (CAS no. 1195-79-5) onto soil (S. R. Hutchins, et. al; 1983). Initial concentration of the test chemical used for the study was0.068 µg/l. To minimize adsorptive and leaching effects, the entire column system was constructed of Teflon and glass. Four columns were constructed of 122 cmx7cm i.d. Pyrex tubing and equipped with Teflon stopcocks. The columns were then silyated, cleaned with methanol and methylene chloride and heated at 4OOOC for a period of 2 h. The columns were packed in the following manner:A0.3-g plug of silyated glass wool was inserted above the stopcock, followed by 150 g of Teflon boiling chips (Chemplast) that had been cleaned by Soxhlet extraction with methylene chloride. A final plugof5.0g silyated glass wool was placed on top of the Teflon boiling chips. Topsoil was obtained from one of the basins at the field site. The soil was packed in its natural state (8.8% moisture content) without sieving.Rocks, organic debris and soil aggregates>3.5 cm in diameter were discarded. The columns were packed, using glass rods, by stepwise addition of 1.0-cm increments of soil. The soil was distributed gently across the cross-sectional area, with care taken to minimize breakage of soil aggregates. Packing continued until a soil core length of 107 cm was obtained. The effluent ends of the columns were then fitted with Teflon Chemfluor connectors (Chemplast) and %-inch(5mm) Teflon tubing and connected to reservoirs containing a known amount of resin-extracted (RE) water. Thecolumns were saturated in an upward direction by gravity feed in step increments of 5.0 cm every 12 h.The columns were connected to feedreservoirs and operated via a Mariotte siphon to maintain a constant head of 3 cm on the soil. Feed reservoirs were constructed from 4-liter amber glass jugs and sealed with Teflon caps. Columns were then wrapped with aluminum foil to prevent light entry and algal growth. The ambient temperature of the incubator was adjusted to 2O°C. Connections were made to deliver feed solution to the reservoirs by gravity from a storage reservoir maintained at 4°C. Infiltration rates for the columns varied from 56 to 78 cm/week.Once effluent began eluting from the columns, flow rate was restricted to 1.2 to 1.7 ml/min with the effluent needle valve. At the end of the 2-d flooding period, the siphon was broken and columns were allowed to drain at normal speed. Effluent was collected to measure the total eluted volume. After feed solution had drained to the top of the soil, sterile air flow was initiated to the column headspace at 15 to 20 cm3/min to produce air. Air was maintained on the columns during the entire drying period and disconnected just before the next inundation cycle. Sampling for trace organics occurred from the time of the first appearance of column eluate to the point at which the siphon feed to the columns was disconnected. Soil columns were maintained through eight inundation cycles. During the seventh and eighth inundation cycles, mercuric chloride was added as a biocide to the feed solution for two of the columns.Trace organics were concentrated and analyzed by a modification of the resin extraction method. The extract was further concentrated to 100-p 1 by nitrogen gas. AI00-µlsyringe was used to adjust the final volume and transfer the extract to storage vials with Teflon-lined septa. Samples were initially analyzed on a Tracor 560 gas chromatograph using capillary columns with flame ionization detectors. Operating parameters were as follows: injection port temperature, 270°C; detector temperature, 300°C; oven temperature, 50°C for 4 min, programmed to 27O°C at 8°C/min. An SP2 100 fused-silica column, 50 m in length, was used with a flow rate of 1 .0ml/min for capillary work. Identification and quantitation by reverse ion search was done using a Finnigan 4000 gas chromatograph/mass spectrometer. Quantitation was done by internal and external standards, using both the base ion intensity and peak area generated in the reconstructed ion chromatogram.As the initial concentration of the chemical was 0.068 µg/l and the recovery of test material 3,3-Dimethyl-8,9-dinorbornan-2-one was determined to be 0.059± 0.012 µg/l. Thus, based on this, chemical 3,3-Dimethyl-8,9-dinorbornan-2-one can be considered to have negligible sorption to soil and sediment and therefore have rapid migration potential to groundwater.

Additional information

Biodegradation in water

Experimental key study and supporting data for the target compound 3,3-Dimethyl-8,9-dinorbornan-2-one (CAS No. 1195-79-5) and supporting study for its structurally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (P. J. Chapman, et. al; 1965),biodegradation study was conducted for evaluating the percentage biodegradability of test substance 3,3-Dimethyl-8,9-dinorbornan-2-one (CAS no. 1195-79-5).Corynebacterium spp. (Bacteria), an organism which grows at the expense of either (+)- or (-)- camphor was used as a test inoculum for the study. Corynebacterium sp., strain T1, was inoculated from stock culture slants into 100 ml sterile nutrient broth (Difco; 8.0 g/liter) and grown at 30°C with shaking for 24 hours. Then, 10 ml portions were used to inoculate the test vessel containing the test chemical 3,3-Dimethyl-8,9-dinorbornan-2-one. Ten ml portions were used to inoculate six 2 liter Erlenmeyer flasks each containing 400 ml of sterile broth. After 24 hours incubation 2.4 g3,3-Dimethyl-8,9-dinorbornan-2-onein N,N,-dimethyl formamide (0.25 g/ml) was equally divided among all six flasks and incubation continued for a further 24 hours. The cells were then centrifuged and the clear neutral supernatant extracted 3 times with 0.5 vol. diethyl ether. The ether solution, after drying over anhydrous Na2SO4, was taken to dryness and 1.12 g of pale yellow crystalline solid obtained. When crystallized from light petroleum (b.p. range 60-68°C) at -72°C, the material had m.p. 73-75°C, λCHCl3max 5.48µ (Found: C, 70.82; H 9.49. C10H16O2 requires C, 71.4; H, 9.52). Thin layer chromatography on silica gel G Drinkmann with ether-light petroleum (40:60, v/v) as solvent, revealed a single component reacting with alkaline hydroxylamine and detectable as its purple ferric hydroxamate. Gas chromatography on a stationary phase of 5% silicone gum rubber SE-30 at 150°C gave only a single peak but on 5% butanediol succinate polyester at 150°C a second component, approximately 10% of the total peak area, was distinguishable. A mixture of authentic 1,2- and 2,3-fencholides, obtained by the Baeyer-Villiger oxidation of 3,3-Dimethyl-8,9-dinorbornan-2-one (fenchone) with peracetic acid, showed essentially the same chromatographic properties as the biologically derived material. It will be noted that the major component corresponds to the 1,2-fencholide.Thus, based on this, 3,3-Dimethyl-8,9-dinorbornan-2-one is considered to be biodegradable in nature.

 

In a supporting study from peer reviewed journal (B. C. J. Zoeteman, et. al; 1981), persistence of the test chemical  3,3-Dimethyl-8,9-dinorbornan-2-one (CAS no. 1195-79-5) was determined in groundwater at Netherlands and Noordwijk, respectively .The estimated half-life value of chemical in groundwater at Netherlands and Noordwijk was determined to be 109.5 and 219 days, respectively. Thus, based on this, 3,3 -Dimethyl-8,9 -dinorbornan-2 -one is considered as persistent in water and can be evaluated to be not readily biodegradable in nature.

 

For the read across chemical (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (CAS no. 76-22-2) from authoritative database (J-CHECK and HSDB, 2017), biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of the read across substance(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one(CAS no. 76-22-2). The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I) under aerobic conditions. Activated sludge was used as a test inoculums for the study. Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one was determined to be 94% and 100% by BOD and GC parameter in 28 days. Thus, based on percentage degradation, (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one is considered to be readily biodegradable in nature.

 

Although the supporting estimated data for the target chemical 3,3-Dimethyl-8,9-dinorbornan-2-one indicates that the chemical is not readily biodegradable, but based onthe experimental key study (from peer reviewed journal) which indicates that the target chemical 3,3-Dimethyl-8,9-dinorbornan-2-one is biodegradable in 48 hrs resulting in the biodegradable products as 1,2- and 2,3-fencholides, respectively, it can be considered that the chemical is expected to be readily biodegradable in 28 days and for its read across substance (from authoritative database J-CHECK and HSDB), it can be concluded that the test substance 3,3-Dimethyl-8,9-dinorbornan-2-one can be expected to be readily biodegradable in nature.

 

Bioaccumulation: aquatic / sediment

Various predicted data for the target compound 3,3-Dimethyl-8,9-dinorbornan-2-one(CAS No. 1195-79-5) and supporting weight of evidence study for its structurally similar read across substance were reviewed for the bioaccumulation end point which are summarized as below:

 

In aprediction done using the BCFBAF Program(v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (CAS No. 1195 -79 -5). The bioconcentration factor (BCF) of 3,3-Dimethyl-8,9-dinorbornan-2-one was estimated to be 97.61 L/kg whole body w.w (at 25 deg C).

 

Bioconcentration Factor (BCF) of test chemical 3,3-Dimethyl-8,9-dinorbornan-2-one was estimated using Chemspider database(ChemSpider, 2017). The bioconcentration factor of test substance 3,3-Dimethyl-8,9-dinorbornan-2-one was estimated to be 59.54 at pH both 5.5 and 7.4, respectively.

 

Another predicted data was estimated usingSciFinder database (American Chemical Society (ACS), 2017) was used for predicting the bioconcentration factor (BCF) of test chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (CAS No. 1195 -79 -5). The bioconcentration factor (BCF) of 3,3-Dimethyl-8,9-dinorbornan-2-one was estimated to be 22.8 at pH range 1-10, respectively (at 25 deg C).

 

From CompTox Chemistry Dashboard using OPERA (OPEn (quantitative) structure-activity Relationship Application)  V1.02 model in which calculation based on PaDEL descriptors (calculate molecular descriptors and fingerprints of chemical), the bioaccumulation i.e BCF for test substance 3,3-Dimethyl-8,9-dinorbornan-2-one was estimated to be 6.24 dimensionless . The predicted BCF result based on the 5 OECD principles.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (CAS no. 76-22-2), bioaccumulation study in fish was conducted for estimating the BCF (bioaccumulation factor) value of read across chemical (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one(CAS no. 76-22-2). The bioaccumulation factor (BCF) value was calculated using a measured log Kow of 2.38 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of (1R,4R)-1,7,7 -trimethylbicyclo[2.2.1]heptan-2 -one in fish was determined to be 17 dimensionless, which does not exceed the bioconcentration threshold of 2000, indicating that the chemical (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one is considered to be non-accumulative in aquatic organisms.

 

On the basis of above results for target chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (from EPI suite,ChemSpider, SciFinder database and CompTox Chemistry Dashboard,  2017) and for its read across substance (from authoritative database HSDB), it can be concluded that the BCF value of test substance 3,3-Dimethyl-8,9-dinorbornan-2-one ranges from 6.24–97.61 which does not exceed the bioconcentration threshold of 2000, indicating that the chemical 3,3-Dimethyl-8,9-dinorbornan-2-one is not expected to bioaccumulate in the food chain.

Adsorption / desorption

Experimental study and predicted data for the target compound 3,3-Dimethyl-8,9-dinorbornan-2-one (CAS No. 1195-79-5) and supporting study for its structurally similar read across substance were reviewed for the adsorption end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (S. R. Hutchins, et. al; 1983),adsorption study was conducted at a temperature of 20°C for evaluating the adsorption capacity of test chemical Disodium 3,3-Dimethyl-8,9-dinorbornan-2-one (CAS no. 1195-79-5) onto soil. Initial concentration of the test chemical used for the study was0.068 µg/l. To minimize adsorptive and leaching effects, the entire column system was constructed of Teflon and glass. Four columns were constructed of 122 cmx7cm i.d. Pyrex tubing and equipped with Teflon stopcocks. The columns were then silyated, cleaned with methanol and methylene chloride and heated at 4OOOC for a period of 2 h. The columns were packed in the following manner: A 0.3-g plug of silyated glass wool was inserted above the stopcock, followed by 150 g of Teflon boiling chips (Chemplast) that had been cleaned by Soxhlet extraction with methylene chloride. A final plugof5.0g silyated glass wool was placed on top of the Teflon boiling chips. Topsoil was obtained from one of the basins at the field site. The soil was packed in its natural state (8.8% moisture content) without sieving. Rocks, organic debris and soil aggregates>3.5 cm in diameter were discarded. The columns were packed, using glass rods, by stepwise addition of 1.0-cm increments of soil. The soil was distributed gently across the cross-sectional area, with care taken to minimize breakage of soil aggregates. Packing continued until a soil core length of 107 cm was obtained. The effluent ends of the columns were then fitted with Teflon Chemfluor connectors (Chemplast) and %-inch(5mm) Teflon tubing and connected to reservoirs containing a known amount of resin-extracted (RE) water. The columns were saturated in an upward direction by gravity feed in step increments of 5.0 cm every 12 h. The columns were connected to feedreservoirs and operated via a Mariotte siphon to maintain a constant head of 3 cm on the soil. Feed reservoirs were constructed from 4-liter amber glass jugs and sealed with Teflon caps. Columns were then wrapped with aluminum foil to prevent light entry and algal growth. The ambient temperature of the incubator was adjusted to 2O°C. Connections were made to deliver feed solution to the reservoirs by gravity from a storage reservoir maintained at 4°C. Infiltration rates for the columns varied from 56 to 78 cm/week. Once effluent began eluting from the columns, flow rate was restricted to 1.2 to 1.7 ml/min with the effluent needle valve. At the end of the 2-d flooding period, the siphon was broken and columns were allowed to drain at normal speed. Effluent was collected to measure the total eluted volume. After feed solution had drained to the top of the soil, sterile air flow was initiated to the column headspace at 15 to 20 cm3/min to produce air. Air was maintained on the columns during the entire drying period and disconnected just before the next inundation cycle. Sampling for trace organics occurred from the time of the first appearance of column eluate to the point at which the siphon feed to the columns was disconnected. Soil columns were maintained through eight inundation cycles. During the seventh and eighth inundation cycles, mercuric chloride was added as a biocide to the feed solution for two of the columns. Trace organics were concentrated and analyzed by a modification of the resin extraction method. The extract was further concentrated to 100-p 1 by nitrogen gas. AI00-µlsyringe was used to adjust the final volume and transfer the extract to storage vials with Teflon-lined septa. Samples were initially analyzed on a Tracor 560 gas chromatograph using capillary columns with flame ionization detectors. Operating parameters were as follows: injection port temperature, 270°C; detector temperature, 300°C; oven temperature, 50°C for 4 min, programmed to 27O°C at 8°C/min. An SP2 100 fused-silica column, 50 m in length, was used with a flow rate of 1 .0ml/min for capillary work. Identification and quantitation by reverse ion search was done using a Finnigan 4000 gas chromatograph/mass spectrometer. Quantitation was done by internal and external standards, using both the base ion intensity and peak area generated in the reconstructed ion chromatogram. As the initial concentration of the chemical was 0.068 µg/l and the recovery of test material 3,3-Dimethyl-8,9-dinorbornan-2-one was determined to be 0.059± 0.012 µg/l. Thus, based on this, chemical 3,3-Dimethyl-8,9-dinorbornan-2-one can be considered to have negligible sorption to soil and sediment and therefore have rapid migration potential to groundwater.

 

In a prediction done using theKOCWIN Program(v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical 3,3 -Dimethyl-8,9 -dinorbornan-2 -one (CAS No. 1195 -79 -5). The soil adsorption coefficient i.e Koc value of 3,3 -Dimethyl-8,9 -dinorbornan-2 -one was estimated to be 114.8 L/kg (log Koc= 2.0601) by means of MCI method (at 25 deg C). This Koc value indicates that the substance 3,3-Dimethyl-8,9-dinorbornan-2-one has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

In a supporting study from authoritative database (HSDB, 2017) for the read across chemical (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (CAS no. 76-22-2),adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of read across chemical (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (CAS no. 76-22-2). The adsorption coefficient (Koc) value was calculated using a structure estimation method based on molecular connectivity indices. The adsorption coefficient (Koc) value of test substance (1R,4R)-1,7,7 -trimethylbicyclo[2.2.1]heptan-2 -one was estimated to be 117 (Log Koc = 2.068). This Koc value indicates that the substance (1R,4R)-1,7,7 -trimethylbicyclo[2.2.1]heptan-2 -one has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

On the basis of above overall results for target chemical 3,3-Dimethyl-8,9-dinorbornan-2-one (from peer reviewed journal and EPI suite) and for its read across substance (from authoritative database HSDB, 2017), it can be concluded that thetest chemical 3,3-Dimethyl-8,9-dinorbornan-2-one has a negligible to low sorption to soil and sediment and therefore have rapid to moderate migration potential to ground water.