1-(2,4-dimethylphenylazo)-2-naphthol

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species, other

Remarks:

aquatic organisms

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

Qualifier:

according to guideline

Guideline:

other: Modelling database

Principles of method if other than guideline:

Prediction done using Bioconcentration factor (v12.1.0.50374).This particular module provides bioconcentration factor (BCF) values over the entire pH scale. Calculations are performed for both neutral and ionic species present at a given pH and utilize predicted values for LogP as well as pKa. The BCF and Koc values characterize the tendency for a compound to accumulate in aquatic organisms and soil respectively, putting these two values among the most important ones in the assessment of environmental fate of chemicals.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol
- Common name: Sudan II
- Molecular formula: C18H16N2O
- Molecular weight: 276.337 g/mol
- Smiles notation: c12c(\N=N/c3c(cc(C)cc3)C)c(ccc1cccc2)O
- InChl:1S/C18H16N2O/c1-12-7-9-16(13(2)11-12)19-20-18-15-6-4-3-5-14(15)8-10-17(18)21/h3-11,21H,1-2H3
- Substance type: Organic
- Physical state: Solid

Radiolabelling:

not specified

Vehicle:

not specified

Test organisms (species):

other: aquatic organisms

Route of exposure:

aqueous

Test type:

not specified

Water / sediment media type:

natural water: freshwater

Reference substance (positive control):

not specified

Key result

Type:

BCF

Value:

4 878 dimensionless

Basis:

whole body w.w.

Calculation basis:

other: no data

Remarks on result:

other: log(BCF) = 3.7 ± 1.0, BCF reported at pH range 1-8

Key result

pH:

9

Type:

BCF

Value:

4 877 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: log(BCF) = 3.7 ± 1.0

Key result

pH:

10

Type:

BCF

Value:

4 876 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: log(BCF) = 3.7 ± 1.0

Key result

pH:

11

Type:

BCF

Value:

4 863 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: log(BCF) = 3.7 ± 1.0

Key result

pH:

12

Type:

BCF

Value:

4 734 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: log(BCF) = 3.7 ± 1.0

Key result

pH:

13

Type:

BCF

Value:

3 746 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: log(BCF) = 3.6 ± 1.0

Key result

pH:

14

Type:

BCF

Value:

1 215 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: log(BCF) = 3.1 ± 1.0

Validity criteria fulfilled:

not specified

Conclusions:

Using Bio-concentration Factor (v12.1.0.50374) module, the BCF value of the test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol at pH range 0-8 was estimated to be 4878 and at pH 9, 10, 11, 12, 13 and 14 was estimated to be 4877, 4876, 4863, 4734, 3746 and 1215, respectively (Log BCF ranges from 3.1 ± 1.0 to 3.7 ± 1.0).

Executive summary:

Using Bio-concentration Factor (v12.1.0.50374) module, the BCF value of the test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS no. 3118 -97 -6) at pH range 0-8 was estimated to be 4878 and at pH 9, 10, 11, 12, 13 and 14 was estimated to be 4877, 4876, 4863, 4734, 3746 and 1215, respectively (Log BCF ranges from 3.1 ± 1.0 to 3.7 ± 1.0). This value indicates that the test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was considered to be accumulative in aquatic organisms.

Description of key information

Using Bio-concentration Factor (v12.1.0.50374) module (Advanced Chemistry Development)/I-Lab predictive module, 2017), the BCF value of the test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS no. 3118 -97 -6) at pH range 0-8 was estimated to be 4878 and at pH 9, 10, 11, 12, 13 and 14 was estimated to be 4877, 4876, 4863, 4734, 3746 and 1215, respectively (Log BCF ranges from 3.1 ± 1.0 to 3.7 ± 1.0). This value indicates that the test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was considered to be accumulative in aquatic organisms.

Key value for chemical safety assessment

BCF (aquatic species):

4 878 dimensionless

Additional information

Various predicted data for the target compound1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol(CAS No. 3118-97-6) and the supporting weight of evidence studies for its read across substance were reviewed for the bioaccumulation end point which are summarized as below:

 

In a prediction done by using Bio-concentration Factor (v12.1.0.50374) module (Advanced Chemistry Development)/I-Lab predictive module, 2017), the BCF value of the test substance 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS no. 3118 -97 -6) at pH range 0-8 was estimated to be 4878 and at pH 9, 10, 11, 12, 13 and 14 was estimated to be 4877, 4876, 4863, 4734, 3746 and 1215, respectively (Log BCF ranges from 3.1 ± 1.0 to 3.7 ± 1.0).

 

The bioaccumulation study from authoritative database (SRC PhysProp database, 2017) was conducted for estimating the BCF (bioaccumulation factor) value of test chemical 1- (2, 4-dimethylphenylazo)-2-naphthol (CAS no. 3118-97-6). The BCF (bioaccumulation factor) value of 1- (2, 4-dimethylphenylazo)-2-naphthol was determined to be 11748.97 dimensionless (log BCF = 4.07).

 

Bioaccumulation test was conducted for estimating the bioconcentration factor (BCF) of test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS no. 3118 -97 -6)(ChemSpider, 2017). The estimated bioconcentration factor (BCF) of 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was estimated to be 7107.84 at pH 5.5 and 7.4, respectively.

 

Another predicted data was estimated usingSciFinder database (American Chemical Society (ACS), 2017) was used for predicting the bioconcentration factor (BCF) of test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No. 3118 -97 -6). The estimated bioconcentration factor (BCF) of 1-[(2,4-dimethyl phenyl)diazenyl]-2-naphthol was estimated to be 8480 at pH range 1-9 and 8470 at pH 10 (at 25 deg C), respectively.

 

For the read across chemical 1-[(2-methoxyphenyl)diazenyl]-2-naphthol (CAS no. 1229-55-6) from authoritative database (HSDB, 2017),bioaccumulation study was conducted for estimating the BCF (bioaccumulation factor) value of read across chemical 1-[(2-methoxyphenyl)diazenyl]-2-naphthol. The bioaccumulation factor (BCF) value was calculated using an estimated log Kow of 7.5 and a regression derived equation. The BCF (bioaccumulation factor) value of 1-[(2-methoxyphenyl)diazenyl]-2-naphthol was determined to be 290000 dimensionless.

 

On the basis of above results for target chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol(from ACD labs,SRC PhysProp database, ChemSpider and SciFinder database,2017) and for its read across substance from HSDB, it can be concluded that the BCF value of test substance1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol ranges from 1215 –11748.97which exceeds the bioconcentration threshold of 2000, indicating that the chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol is expected to bioaccumulate in the food chain.