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Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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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:
other: Modeling database
Principles of method if other than guideline:
Prediction done using BCFBAF (v3.01) model
GLP compliance:
not specified
Specific details on test material used for the study:
- Name of test material (IUPAC name): Ethyl 2-naphthyl ether
- Molecular formula: C12H12O
- Molecular weight: 172.226 g/mol
- Smiles notation: c12c(ccc(c1)OCC)cccc2
- InChl: 1S/C12H12O/c1-2-13-12-8-7-10-5-3-4-6-11(10)9-12/h3-9H,2H2,1H3
- Substance type: Organic
- Physical state: Solid
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:
136.6 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)CC

CHEM : Naphthalene, 2-ethoxy-

MOL FOR: C12 H12 O1

MOL WT : 172.23

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

Summary Results:

Log BCF (regression-based estimate): 2.14 (BCF = 137 L/kg wet-wt)

Biotransformation Half-Life (days) : 3.25 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 2.61 (BAF = 408 L/kg wet-wt)

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 3.74

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 = 2.135 (BCF = 136.6 L/kg wet-wt)

Validity criteria fulfilled:
not specified
Conclusions:
The bioconcentration factor (BCF) of Ethyl 2-naphthyl ether was estimated to be 136.6 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical Ethyl 2-naphthyl ether 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 Ethyl 2-naphthyl ether (CAS No. 93 -18 -5). The bioconcentration factor (BCF) of Ethyl 2-naphthyl ether  was estimated to be 136.6 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical Ethyl 2-naphthyl ether  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 Ethyl 2-naphthyl ether (CAS No. 93 -18 -5). The bioconcentration factor (BCF) of Ethyl 2-naphthyl ether  was estimated to be 136.6 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical Ethyl 2-naphthyl ether  is not expected to bioaccumulate in the food chain.

Key value for chemical safety assessment

BCF (aquatic species):
136.6 L/kg ww

Additional information

Various predicted data for the target compound Ethyl 2-naphthyl ether (CAS No.93-18-5) and supporting weight of evidence studies for its structurally similar read across substances 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 Ethyl 2-naphthyl ether (CAS No. 93 -18 -5). The bioconcentration factor (BCF) of Ethyl 2-naphthyl ether was estimated to be 136.6 L/kg whole body w.w (at 25 deg C).

 

In an another prediction done by using Bio-concentration Factor module, Bio-concentration Factor of the test substance Ethyl 2-naphthyl ether (CAS no. 93 -18 -5) was estimated to be 538 dimensionless at pH range 1-14, respectively (ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017)).

 

Bioconcentration Factor (BCF) of test chemical Ethyl 2-naphthyl ether (CAS no. 93 -18 -5) was estimated using Chemspider database (modelling database, 2017). The bioconcentration factor of test substance Ethyl 2-naphthyl ether was estimated to be 424.95 at pH both 5.5 and 7.4, respectively.

 

Another predicted data was estimated using SciFinder database (American Chemical Society (ACS), 2017) for predicting the bioconcentration factor (BCF) of test chemical Ethyl 2-naphthyl ether (CAS No. 93 -18 -5). The bioconcentration factor (BCF) of Ethyl 2-naphthyl ether was estimated to be 509 at pH range 1-10 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 substance Ethyl 2-naphthyl ether was estimated to be 371 dimensionless . The predicted BCF result based on the 5 OECD principles.

 

In a supporting weight of evidence study from authoritative databases (J-CHECK, 2018 and EnviChem, 2014) for the test item,bioaccumulation experiment 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/land 0.005 mg/l, respectively.Test chemical solution was prepared in HCC. 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 the LC50(48h) 11.1 mg/L on 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.

 

For the test chemical,bioaccumulation study was conducted for estimating the BCF (bioaccumulation factor) value of test chemical (HSDB and PubChem, 2017). The bioaccumulation factor (BCF) value was calculated using an experimental logKow of 2.51 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of test chemical was determined to be 48 dimensionless.

 

On the basis of above results for target chemical Ethyl 2-naphthyl ether (from modelling databases,2017), it can be concluded that the BCF value of test substance Ethyl 2-naphthyl ether ranges from 136.6 –538, respectively,which does not exceed the bioconcentration threshold of 2000, indicating that the chemical Ethyl 2-naphthyl ether is not expected to bioaccumulate in the food chain.