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Environmental fate & pathways

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Bioaccumulation: aquatic / sediment

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.

Additional information

Bioaccumulation: aquatic / sediment

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.