Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Stability:

Hydrolysis:

The half life of test chemical was estimated by using the EPI suite Hydrowin model.

The half life of hydrolysis of test chemical was estimated to be 61.4 and 6.14 days at pH 7 and 8 respectively, the hydrolysis rate constant was estimated to be 1.31 L/mol-sec. On the basis of half life value test chemical is considered to be stable.

Biodegradation:

Biodegradation in water:

Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test chemical in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical is expected to be not readily biodegradable.

Bioaccumulation:

Bioaccumulation: aquatic/sediments:

Using BCFBAF Program (v3.00) model of EPI suite (2018) the estimated bio concentration factor (BCF) for test chemical  is  3.162 L/kg wet-wt at 25 deg. c which does not exceed the bioconcentration threshold of 2000. Therefore it is concluded that test chemical is nonbioaccumulative in food chain.

Transport and distribution:

Adsorption/desorption:

The Soil Adsorption Coefficient i.e. Koc value of test chemical  was estimated using EPI suite KOCWIN Program (v2.00) as 70400.L/kg (log Koc= 4.847) by means of MCI method at 25 deg. C.  This log Koc value indicates that test chemical  has very strong sorption to soil and therefore test chemical has  negligible migration potential to ground water.

Additional information

Stability:

Hydrolysis:

The half life of test chemical was estimated by using the EPI suite Hydrowin model.

The half life of hydrolysis of test chemical was estimated to be 61.4 and 6.14 days at pH 7 and 8 respectively, the hydrolysis rate constant was estimated to be 1.31 L/mol-sec. On the basis of half life value test chemical is considered to be stable.

Biodegradation:

Biodegradation in water:

Predicted data of the test chemical and various supporting studies for its structurally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction done using Estimation Programs Interface Suite (2018), the biodegradation potential of the test chemical in the presence of mixed populations of environmental microorganisms was predicted. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that test chemical is expected to be not readily biodegradable.

 

In a supporting weight study from authoritative database (J-CHECK, 2018) and secondary source (2014), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I). 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 chemical was determined to 6% by using BOD and HPLC parameter in 28 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in water.

 

For the test chemical, biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical. 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 chemical was determined to 0 and 4% by using BOD and UV-Vis parameter in 28 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in water.

 

On the basis of above overall results of test chemical, it can be concluded that the test chemical can be considered to be not readily biodegradable in nature.

Bioaccumulation:

Bioaccumulation: aquatic/sediments:

Different predicted data study for test chemical and experimental studies for its read across chemicals have been reviewed for bioaccumulation endpoint and their results are summarized below.

 

In first study BCF value of test chemical was estimated by using BCFBAF Program (v3.00) model of EPI suite (2018) and the estimated bio concentration factor (BCF) for test chemical is 3.162 L/kg wet-wt at 25 deg. c which does not exceed the bioconcentration threshold of 2000. Therefore it is concluded that test chemical is non-bioaccumulative in food chain.

 

In next study 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 was estimated to be 279 dimensionless . The predicted BCF result was based on the 5 OECD principles.

Thus based on the result it is concluded that the test substance is non-bioaccumulative in nature.

 

Another study was experimental study reviewed from authoritative database in this Bioaccumulation study was conducted on test organism Cyprinus carpio for 6 weeks for evaluating the bioconcentration factor (BCF value) of test chemical. The study was performed according to “OECD Guideline 305 C (Bioaccumulation: Test for the Degree of Bioconcentration in Fish)” and other guideline "Bioaccumulation test of a chemical substance in fish or shellfish" provided in "the Notice on the Test Method Concerning New Chemical Substances". Cyprinus carpio was used as a test organism for the study. Test chemical nominal conc. used for the study were 1 mg/l and 0.1 mg/l .Test chemical solution was prepared in crystal sugar or HCO-40.Analytical method involve there recovery ratio: Fish : 85.8 %, - Limit of quantitation : Test water : 1st concentration area : 0.024 mg/L, 2nd concentration area : 0.0024 mg/L, Fish : 0.28 microg/g. Range finding study involve the LC50 (48hr) ≥ 400 mg/l on Rice fish (Oryziaslatipes). Lipid content of the test organism Cyprinus carpio was determined to be 4.2% at start of exposure. The bioconcentration factor (BCF value) of test chemical on Cyprinus carpio was determined to be in the range of 0.3 – 2.7 L/Kg at a conc. of 1 mg/l and ≤ 2.9 L/Kg at a conc. of 0.1 mg/l, which does not exceed the bioconcentration threshold of 2000, indicating that the chemical is expected to non-bioaccumulate in the food chain.

 

In next study the bioaccumulation study was conducted for estimating the BCF (bioaccumulation factor) value of test chemical. The bioaccumulation factor (BCF) value was calculated using a log Kow of 6.6 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of test chemical was determined to be 10 dimensionless, which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is expected to be non-bioaccumulative in aquatic organisms.

 

 By considering results of all the studies mentioned above it is concluded that test chemical is non bioaccumulative. .

Transport and distribution:

Adsorption/desorption:

Different predicted data study for test chemical and experimental studies for its read across chemicals have been reviewed for adsorption /desorption endpoint and their results are summarized below.

 

In first study the Soil Adsorption Coefficient i.e. Koc value of test chemical was estimated using EPI suite KOCWIN Program (v2.00) as 70400.L/kg (log Koc= 4.847) by means of MCI method 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 adsorption coefficient i.e KOC for test substance was estimated to be 9220 L/kg ( log koc=3.9647) .The predicted KOC result was based on the 5 OECD principles.

 

The next Adsorption study was conducted for estimating the adsorption coefficient (Koc) value of test chemical. 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 was estimated to be 230000 (Log Koc = 5.361).

 

Another adsorption study was conducted for estimating the adsorption coefficient (Koc) value of test chemical. 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 was estimated to be 130000 (Log Koc = 5.113).

 

By considering results of all the studies mentioned above it is concluded the log Koc value of test chemical is expected to be in range of 3.9- 5.3 and this range value indicates that the test chemical has a very strong sorption to soil and sediment and therefore has negligible migration potential to ground water.