Methyl 2-naphthyl ether

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: Modelling database

Principles of method if other than guideline:

Prediction done using BCFBAF (v3.01) model

GLP compliance:

no

Radiolabelling:

no

Vehicle:

no

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

Key result

Type:

BCF

Value:

90.47 L/kg

Basis:

whole body w.w.

Calculation basis:

other: estimated

Remarks on result:

other: Non bioaccumulative

BCFBAF Program (v3.01) Results:

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

SMILES : O(c(ccc(c1ccc2)c2)c1)C

CHEM : Naphthalene, 2-methoxy-

MOL FOR: C11 H10 O1

MOL WT : 158.20

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

Summary Results:

Log BCF (regression-based estimate): 1.96 (BCF = 90.5 L/kg wet-wt)

Biotransformation Half-Life (days) : 2.76 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 2.39 (BAF = 246 L/kg wet-wt)

Log Kow (experimental): 3.47

Log Kow used by BCF estimates: 3.47

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 = 1.957 (BCF = 90.47 L/kg wet-wt)

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

Whole Body Primary Biotransformation Rate Estimate for Fish:

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

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Aromatic ether [-O-aromatic carbon] | -0.0694 | -0.0694

Frag | 7 | Aromatic-H | 0.2664 | 1.8646

Frag | 1 | Methyl [-CH3] | 0.2451 | 0.2451

Frag | 2 | Number of fused 6-carbon aromatic rings | -0.5779 | -1.1557

Frag | 1 | Naphthalene | 0.4320 | 0.4320

L Kow| * | Log Kow = 3.47 (experimental ) | 0.3073 | 1.0665

MolWt| * | Molecular Weight Parameter | | -0.4057

Const| * | Equation Constant | | -1.5371

============+============================================+=========+=========

RESULT | LOG Bio Half-Life (days) | | 0.4404

RESULT | Bio Half-Life (days) | | 2.757

NOTE | Bio Half-Life Normalized to 10 g fish at 15 deg C |

============+============================================+=========+=========

Biotransformation Rate Constant:

kM (Rate Constant): 0.2515 /day (10 gram fish)

kM (Rate Constant): 0.1414 /day (100 gram fish)

kM (Rate Constant): 0.07952 /day (1 kg fish)

kM (Rate Constant): 0.04472 /day (10 kg fish)

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

Estimated Log BCF (upper trophic) = 2.391 (BCF = 246.1 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 2.392 (BAF = 246.4 L/kg wet-wt)

Estimated Log BCF (mid trophic) = 2.254 (BCF = 179.3 L/kg wet-wt)

Estimated Log BAF (mid trophic) = 2.256 (BAF = 180.3 L/kg wet-wt)

9

Estimated Log BCF (lower trophic) = 2.206 (BCF = 160.6 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 2.212 (BAF = 162.8 L/kg wet-wt)

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

Estimated Log BCF (upper trophic) = 2.496 (BCF = 313.3 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 2.638 (BAF = 434.5 L/kg wet-wt)

Validity criteria fulfilled:

not specified

Conclusions:

The bioconcentration factor (BCF) of test chemical was estimated to be 90.47 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical is not expected to bioaccumulate in the food chain.

Executive summary:

BCFBAF model (v3.01) of Estimation Programs Interface (2018) was used to predict the bioconcentration factor (BCF) of test chemical . The bioconcentration factor (BCF) of test chemical was estimated to be 90.47 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical is not expected to bioaccumulate in the food chain.

Description of key information

BCFBAF model (v3.01) of Estimation Programs Interface (2018) was used to predict the bioconcentration factor (BCF) of test chemical . The bioconcentration factor (BCF) of test chemical was estimated to be 90.47 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical is not expected to bioaccumulate in the food chain.

Key value for chemical safety assessment

BCF (aquatic species):

90.47 L/kg ww

Additional information

Various predicted data for 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 aprediction done using the BCFBAF Program(v3.01) of Estimation Programs Interface (2018) prediction program was used to predict the bioconcentration factor (BCF) of test chemical. The bioconcentration factor (BCF) of test chemical was estimated to be 90.47 L/kg whole body w.w (at 25 deg C).

Another prediction was done by using OECD QSAR toolbox version 3.4 (2019) to estimate the bioaccumulation value (BCF) of test chemical in fish. The BCF value was estimated to be 366 dimensionless whole body w.w.

 

In an another prediction done by using Bio-concentration Factor (v12.1.0.50374) moduleACD (Advanced Chemistry Development)/I-Lab predictive module, 2017), thebio-concentration factor over the entire pH scale (pH 1 -14) of the test chemical was estimated to be 212.

 

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 293 dimensionless . The predicted BCF result based on the 5 OECD principles.

 

In a supporting weight of evidence study from authoritative database (2017) and secondary source, bioaccumulation study was conducted on test organism Cyprinus carpio for 8 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 0.05 mg/l and 0.005 mg/l, respectively. Test chemical solution was prepared in HCO-40. Analytical method involve the recovery ratio: Test water : 1st concentration area : 87.3 %, 2nd concentration area : 90.0 %, Fish : 91.0 %, - Limit of detection : Test water: 1st concentration area : 2.4 ng/ml, 2nd concentration area : 0.23 ng/ml, Fish : 69 ng/g. Range finding study involve theLC50(48h) 11.1 mg/Lon Rice fish (Oryzias latipes). Lipid content of the test organism Cyprinus carpio was determined to be 4.1% at the start of exposure. The bioconcentration factor (BCF value) of substance on Cyprinus carpio was determined to be in the range of 431-1180 L/Kg at a conc. of 0.05 mg/l and 398-873 L/Kg at a conc. of 0.005 mg/l, respectively, which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

 

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 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", respectively at 25°C. Cyprinus carpio was used as a test organism for the study. Test chemical nominal conc. used for the study were 0.1mg/l and 0.01 mg/l, respectively. Test chemical solution was prepared in HCO-20. Analytical method involve the recovery ratio: Test water : 96.7 %, Fish : 88.5 %, - Limit of quantitation : Test water : 1st concentration area : 2.7 microg/L, 2nd concentration area : 0.27 microg/L, Fish : 33 ng/g. Range finding study involve the LC50(48h) ≥ 26 mg/Lon Rice fish (Oryzias latipes). Lipid content of the test organism Cyprinus carpio was determined to be 4.0% at the start of exposure. The bioconcentration factor (BCF value) of test chemical on Cyprinus carpio was determined to be in the range of 6.1 to 63 L/Kg at a conc. of 0.1 mg/l and 5.9 to 23 L/Kg at a conc. of 0.01 mg/l, respectively, which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

 

On the basis of above results of the test chemical, it can be concluded that the BCF value of test chemical was evaluated to be ranges from 5.9 to 1180, respectively,which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.