Exo-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol

Endpoint summary

Description of key information

Stability:

Hydrolysis: The study does not need to be conducted because substance is readily biodegradable.

Biodegradation:

Biodegradation in water:

Biodegradability of test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS no. 124 -76 -5) was estimated by using OECD QSAR tool box v3.3 with log Kow as primary descriptor.The percent biodegradation of test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol was estimated to be 91.2624 % by considering BOD as parameter and microorganisms as inoculum in 28 days. Since percent biodegradation is very high it is concluded that this test chemical readily biodegradable,

Biodegradation in water and sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound 3 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124 -75 -6). If released in to the environment, 25.8 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of the chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol in water is estimated to be 37.5 days (900 hrs). The half-life (37.5days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into sediment is less than 1%( i.e., reported as 0.143 %) indicates that test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol is not persistent in sediments.

Biodegradation in Soil:

The half-life period of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124 -75 -6) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 72.9 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Bioaccumulation:

Bioaccumulation: aqutic/sediments:

From BCFBAF Program (v3.00) model of EPI suite the estimated bio concentration factor (BCF) for 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol(CAS No: 124-75-6) is 27.66 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000. Thus it is concluded that the test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol is not expected to bio accumulate in the aquatic environment.

Transport and distribution:

Adsorption/desorption:

The Soil Adsorption Coefficient i.e Koc value of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No:124-75-6) was estimated using EPI suite KOCWIN Program (v2.00) as 75.77 L/kg (log Koc= 1.8795)  by means of MCI method at 25 deg.C. This Koc value indicates that the substance 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol has a low sorption to soil and sediment and therefore have moderate migration potential to groundwater.

Additional information

Stability:

Hydrolysis:The study does not need to be conducted because substance is readily biodegradable.

Biodegradation:

Biodegradation in water:

One predicted data study for target chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol ( CAS no. 124 -76 -5) and three experimental studies have been conducted for its read across chemicals and their results are summarized below.

In first study biodegradability of target chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol ( CAS no. 124 -76 -5) was estimated by using OECD QSAR tool box v3.3 with log Kow as primary descriptor.The percent biodegradation of test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol was estimated to be 91.2624 % by considering BOD as parameter and microorganisms as inoculum in 28 days. Since percent biodegradation is very high it is concluded that this test chemical readily biodegradable.

Next study was weight of evidence study done from authoritative database ( J check, 2017 )for read across chemical in this study biodegradation experiment was carried out of read across chemical 4,7,7-trimethylbicyclo[2.2.1]heptan-3-one (CAS no. 76-22-2) by taking activated sludge as inoculums at 30 mg/L concentration for 28 days. Biodegradation was analyzed by using two parameters namely, BOD and GC . The initial concentration of read across chemical was 100 mg/L. After 4 weeks of incubation percent biodegradation of read across chemical 4,7,7-trimethylbicyclo[2.2.1]heptan-3-one was observed to be 94 % by BOD parameter 100 % by GC parameter in 28 days. Therefore it is concluded that read across chemical 4,7,7-trimethylbicyclo[2.2.1]heptan-3-one is readily biodegradable.

Another weight of evidence study was done from Water Research Journal (1975) in this study Biodegradation experiment was performed in batch system using adapted activated sludge as inoculums. Activated sludge was obtained from sewage plant then it is adapted for 20 days with the read across chemical (1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS no.507-70-7) in biological medium containing Glucose peptone etc. After activated sludge get adapted concentration of read across chemical was increased upto 200 mg/L and then biodegradation was observed for read across chemical. Read across chemical was the only source of organic carbon. All adaption process and degradation process was taken place in dark room at 20 oC. Experiment was carried out till there is no decrease of COD. Inoculum blank flask was also set up simultaneously. Sampling was done at definite time interval 50-80 mL sample was taken for analyzing COD. The experiment is carried out till there is no decrease of COD. After that time the total percentage of COD removed (% degradation) and the rate of degradation are evaluated. Percent biodegradability of read across chemical(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol observed to be 90.3 % by COD (Organic Carbon ) and rate of degradation was 8.9 mg COD /g/L per hour. Thus it is concluded that read across chemical(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol is readily biodegradable.

Last weight of evidence study was done from authoritative database ( J check, 2017) in this study biodegradation experiment was carried out of read across chemical(1R, 2S, 4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS no. 507-70-0)by taking activated sludge as inoculums at 30 mg/L concentration for 28 days. Biodegradation was analyzed by using three parameters that are BOD, TOC removal and test material analysis by GC . The initial concentration of read across chemical was 100 mg/L. After 4 weeks of incubation percent biodegradation of read across chemical(1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol was observed to be 97 % by O2 consumption ( BOD) parameter 90 % by TOC removal parameter and 100% degradation by test material analysis by GC parameter in 28 days. Therefore it is concluded that read across chemical (1R,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol is readily biodegradable.

On the basis of results of all above studies for target chemical and read across chemical it is concluded that target chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS no. 124 -76 -5) is expected to be readily biodegradable.

Biodegradation in water and sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound 3 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124 -75 -6). If released in to the environment, 25.8 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of the chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol in water is estimated to be 37.5 days (900 hrs). The half-life (37.5days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into sediment is less than 1%( i.e., reported as 0.143 %) indicates that test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol is not persistent in sediments.

Biodegradation in Soil:

The half-life period of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124 -75 -6) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 72.9 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Bioaccumulation:

Bioaccumulation: aqutic/sediments:

Various predicted data for the target compound1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol(CAS No: 124-75-6)and supporting weight of evidence study for its read across chemical were reviewed for the bioaccumulation end point which are summarized as below:

In a prediction done using BCFBAF Program (v3.00) model of EPI suite 2017bio concentration factor (BCF) for 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol(CAS No: 124-75-6)estimated to be 27.66 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000.

In another prediction done using Bio-concentration Factor (v12.1.0.50374) (ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017) module Bio-concentration Factor at range pH 1-12  of the chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS no.124 -75 -6) estimated to be 67.1 dimensionless.

Another predicted data obtained by using Sci Finder database (American Chemical Society (ACS), 2017)and Bioconcentration factor (BCF) for test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124-76-5) was estimated in aquatic organisms by at pH 1-10 and temperature 25 °C .The Bioconcentration factor (BCF) of test substance 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol at pH 1-10 and temperature 25 °C was estimated to be 51.1 dimensionless.  This BCF value at pH 1-10 and temperature 25 °C suggests that the test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol is non bioaccumulative in aquatic organisms.

Similarly, the Bioconcentration factor (BCF) for test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124-75-6) was predicted in aquatic organisms by Chemspider- ACD/PhysChem Suite at pH 5.5 and pH 7.4. The Bioconcentration factor (BCF) of test substance 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol at pH 5.5 and pH 7.4 was estimated to be 54.20 dimensionless. 

Last predicted data study done 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 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS no.124 -75 -6) was estimated to be 15.7 dimensionless it is based on the 5 OECD principles.

 In a supporting weight of evidence study done from authoritative database (HSDB, 2017) the BCF value of read across chemical 2,2,4-trimethyl-3-oxabicyclo[2.2.2]octane (CAS no. 470-82-6) estimated was 30.0 dimensionless by using log Kow of 2.74 and regression derived.

 In another supporting weight of evidence study done from authoritative database ( HSDB, 2017) The BCF value of read across chemical(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one(CAS no. 76-22-2) estimated was 17 dimensionless by using log Kow of 2.38 and regression derived equation.

On the basis of above results for target chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124-75-6)(from EPI suite, ACD labs, Sci Finder database, Chemspider and CompTox Chemistry Dashboard 2017) and for its read across chemicals (From HSDB) it can be concluded that the BCF value of test substance 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124-75-6) ranges from 15.2 to 67.1 dimensionless which does not exceed the bioconcentration threshold of 2000, indicating that the target chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No: 124-75-6) is expected to be non-bioaccumulative in the food chain.

Transport and distribution:

Adsorption/desorption:

Various predicted data for the target compound1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No:124-75-6)and supporting weight of evidence study for its read across chemical were reviewed for the Adsorption end point which are summarized as below.

In first weight of evidence study the Soil Adsorption Coefficient i.e Koc value of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No:124-75-6) was estimated using EPI suite(2017) KOCWIN Program (v2.00) as 75.77 L/kg (log Koc= 1.8795)  by means of MCI method at 25 deg.C. This Koc value indicates that the substance 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol has a low sorption to soil and sediment and therefore have moderate migration potential to groundwater.

In second weight of evidence study the Soil Adsorption Coefficient i.e Koc value of test substance1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol( CAS no. 124 -75 -6) was estimated using Adsorption Coefficient module (v12.1.0.50374) program ofACD (Advanced Chemistry Development)/I-Lab predictive module, 2017) moduleas Koc 707 dimensionless (log Koc= 2.8494) at pH range 1 -12. This log Koc value indicates that the test substance1,7,7-trimethylbicyclo[2.2.1]heptan-2-olhas a moderate sorption to soil and therefore have slow migration potential to groundwater.

Third weight of evidence study done by Using Sci-Finder database of American Chemical Society (2017) and soil adsorption co-efficient i.e.,  Koc value of test chemical 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS no. 124 -75 -6) was estimated to be 581 dimensionless ( log Koc =2.7641) at pH 1-10 at temperature 25 deg.C. This Koc value at all range of pH condition indicates that the substance 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol has moderate sorption to soil and sediment therefore have slow migration potential to ground water.

Another weight of evidence study done by Using Chemspider-ACD/Phy chem suite of Royal Society of Chemistry (2017) and the soil adsorption co-efficient i.e., Koc value of test substance1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol(CAS no 124 -75 -6) was estimated to be 606.48 dimensionless (log Koc= 2.7828) at pH 5.5 and 7.4 and temperature 25 deg.C This Koc value at different pH indicates that the chemical1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol has moderate sorption to soil and sediment and therefore slow migration potential to ground water.

Last weight of evidence study done 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 adsorption coefficient i.e KOC for test substance 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS no.124 -75 -6) was estimated to be 1910 L/kg (log Koc = 3.2810) .The predicted KOC result based on the 5 OECD principles. Thus based on the result it is concluded that the test substance 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

In a supporting weight of evidence study done from authoritative database ( HSDB, 2017) the Koc value for read across chemical 2,2,4-trimethyl-3-oxabicyclo[2.2.2]octane (CAS no.470-82-6) was estimated by using a log Kow of 2.74 and a regression-derived equation. The estimated Koc value was 220 dimensionless and log Koc is 2.3424 this log Koc value suggests that 2,2,4-trimethyl-3-oxabicyclo[2.2.2]octane is expected to have low sorption to soil and sediment and therefore have moderate migration potential to ground water.

In another supporting weight of evidence study done from authoritative database ( HSDB, 2017) the Koc value for read across chemical (1R,2S,5R)-5-methyl-2-propan-2-ylcyclohexan-1-ol (CAS no.2216-51-5) was estimated by using a log Kow of 3.3 and a regression-derived equation. The estimated Koc value was 1500 dimensionless and log Koc is 3.1760 this log Koc valuesuggests that (1R,2S,5R)-5-methyl-2-propan-2-ylcyclohexan-1-ol is expected to have moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

On the basis of above results for target chemical1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol (CAS No:124-75-6)(from EPI suite, ACD labs, Sci Finder database, Comptox chemistry dashboard and Chemspider 2017) and for its read across chemicals (From authoritative database HSDB) it can be concluded that the log Koc value of test substance1,7,7-trimethylbicyclo[2.2.1]heptan-2-olranges from 1.8795 to 3.2810 indicating that the chemical1,7,7-trimethylbicyclo[2.2.1]heptan-2-olhas low to moderate sorption to soil and sediment and therefore have moderate to slow migration potential to ground water.