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

Endpoint summary

Description of key information

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.

Additional information

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.