1,3-dihydro-5-methoxy-2H-benzimidazole-2-thione

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

Estimated data generated using the EPI Suite program developed by the USEPA.

Qualifier:

according to guideline

Guideline:

other: Modeling database

Principles of method if other than guideline:

Prediction done using BCFBAF (v3.01) model

GLP compliance:

not specified

Radiolabelling:

not specified

Vehicle:

not specified

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

not specified

Water / sediment media type:

natural water: freshwater

Test temperature:

25 deg.C

Reference substance (positive control):

not specified

Key result

Temp.:

25 °C

Type:

BCF

Value:

4.751 L/kg

Basis:

whole body w.w.

Calculation basis:

other: estimated

Remarks on result:

other: Non-bioaccumulative

BCFBAF Program (v3.01) Results:

==============================

SMILES : c12NC(=S)Nc1cc(OC)cc2

CHEM :

MOL FOR: C8 H8 N2 O1 S1

MOL WT : 180.23

--------------------------------- BCFBAF v3.01 --------------------------------

Summary Results:

Log BCF (regression-based estimate): 0.68 (BCF = 4.75 L/kg wet-wt)

Biotransformation Half-Life (days) : 0.0833 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 0.54 (BAF = 3.48 L/kg wet-wt)

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 1.53

Equation Used to Make BCF estimate:

Log BCF = 0.6598 log Kow - 0.333 + Correction

Correction(s): Value

No Applicable Correction Factors

Estimated Log BCF = 0.677 (BCF = 4.751 L/kg wet-wt)

Validity criteria fulfilled:

not specified

Conclusions:

The bioconcentration factor (BCF) of test chemical was estimated to be 4.751 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

Executive summary:

BCFBAF model of Estimation Programs Interface was used to predict the bioconcentration factor (BCF) of test chemical. The bioconcentration factor (BCF) of test chemical was estimated to be 4.751 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

Description of key information

BCFBAF model of Estimation Programs Interface was used to predict the bioconcentration factor (BCF) of test chemical. The bioconcentration factor (BCF) of test chemical was estimated to be 4.751 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

Key value for chemical safety assessment

BCF (aquatic species):

4.751 L/kg ww

Additional information

Various predicted data of the test chemical and supporting weight of evidence studies for its structurally and functionally similar read across substance were reviewed for the bioaccumulation end point which are summarized as below:

 

In a prediction done using the BCFBAF Program of Estimation Programs Interface was used to predict the bioconcentration factor (BCF) of test chemical. The bioconcentration factor (BCF) of test chemical was estimated to be 4.751 L/kg whole body w.w (at 25 deg C).

 

In an another prediction done by using Bio-concentration Factor module (ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017)), the bio-concentration Factor of the test chemical was estimated to be 1 dimensionless at pH range 1-14, respectively.

 

Another predicted data was estimated using SciFinder database (American Chemical Society (ACS), 2017) for predicting the bioconcentration factor (BCF) of test chemical. The bioconcentration factor (BCF) of test chemical was estimated to be 7.90, 10.3, 10.6, 10.5, 9.42 and 4.69 at pH range 1, 2, 3-7, 8, 9 and 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 chemical was estimated to be 7.13 dimensionless . The predicted BCF result based on the 5 OECD principles. Thus based on the result it is concluded that the test chemical is non-bioaccumulative in nature.

 

In a supporting weight of evidence study from authoritative database (2018) for the test chemical,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 other guideline "Bioaccumulation test of a chemical substance in fish or shellfish" provided in "the Notice on the Test Method Concerning New Chemical Substances", respectively. Cyprinus carpio was used as a test organism for the study. Test chemical nominal conc. used for the study were 0.5mg/l and 0.05 mg/l, respectively. Range finding study involve the TLm (48 hr) 160 mg/l (w/v) on Rice fish (Oryzias latipes). The bioconcentration factor (BCF value) of test chemical on Cyprinus carpio was determined to be in the range of 0.7-3.5 L/Kg at a conc. of 0.5 mg/l and ≤ 2.6 L/Kg at a conc. of 0.05 mg/l, respectively.

 

For the test chemical, bioaccumulation study was conducted on test organism Cyprinus carpio for 6 weeks for evaluating the bioconcentration factor (BCF value) of test chemical (authoritative databases, 2018). The study was performed according to other guideline "Bioaccumulation test of a chemical substance in fish or shellfish" provided in "the Notice on the Test Method Concerning New Chemical Substances", respectively. Cyprinus carpio was used as a test organism for the study. Test chemical nominal conc. used for the study were 0.5mg/land 0.05 mg/l, respectively. Analytical method involve therecovery ratio: Test water : 1st concentration area : 99.6 %, 2nd concentration area : 101 %, Fish : 89.0 %, - Limit of detection : Fish : 0.14 ppm. Range finding study involve the TLm (48 hr) 27.8 mg/l (w/v) on Rice fish (Oryzias latipes). Lipid content of the test organism Cyprinus carpio was determined to be 5.4%. The bioconcentration factor (BCF value) of test chemical on Cyprinus carpio was determined to be in the range of 0.7-1.8 L/Kg at a conc. of 0.5 mg/l and ≤ 2.9 L/Kg at a conc. of 0.05 mg/l, respectively.

 

On the basis of above results for test chemical, it can be concluded that the BCF value of test chemical was evaluated to be upto 10.6, respectively,which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.