N-(5-chloro-2,4-dimethoxyphenyl)-4-[[5-[(diethylamino)sulphonyl]-2-methoxyphenyl]azo]-3-hydroxynaphthalene-2-carboxamide

Bioaccumulation: aquatic / sediment

Administrative data

Endpoint:

bioaccumulation: aquatic / sediment

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2009

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Probably valid QSAR estimation of BCF using different QSAR models performed by Environment Canada. However reliability not assignable, as details on prediction not published in screening assessment report.

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Data source

Reference

Reference Type:

other: Environmental Agency Assessment Report

Title:

Screening Assessment for the Challenge 2-Naphthalenecarboxamide, N-(5-chloro-2,4-dimethoxyphenyl)-4-[[5- [(diethylamino)sulfonyl]-2-methoxyphenyl]azo]-3-hydroxy- (Pigment Red 5)

Author:

Environment Canada, Health Canada

Year:

2009

Bibliographic source:

http://www.ec.gc.ca/substances/ese/eng/challenge/batch3/batch3_6410-41-9_en.pdf

Materials and methods

Principles of method if other than guideline:

QSAR estimation of fish BCF for Pigment Red 5 (CAS 6410-41-9).

For most organic compounds there is a predictable relationship between KOW and the bioconcentration factor in lipids (Mackay 1982). The ratio log (CO/CW) has been estimated from the experimental solubilities of Pigment Red 5 in octanol (CO) and water (CW), and this experimentally derived ratio has been preferred over the model-derived log KOW for this pigment. This approach is supported by the observation that partitioning into octanol is a good indicator of a substance’s potential to partition into the lipid phase of aquatic biota (Bertelsen et al. 1998) and, for pigments, the observation that a reduced solubility in octanol translates into a similarly reduced bioconcentration factor (BCF) and bioaccumulation factor (BAF) in an aquatic organism (Banerjee and Baughman 1991).

A revised set of BCF estimates for Pigment Red 5 has been obtained from quantitative structure-activity relationship (QSAR)-based bioaccumulation models, using the experimentally based value log (CO/CW) in place of the overestimated log KOW by KOWWIN (2000). The log (CO/CW) used for QSAR-estimations of BCF by Environment Canada is 1.22. This is identical to the value reported in IUCLID section 4.7 for Pigment Red 5.

The following models were applied:
[BCFWIN] BioConcentration Factor Program for Windows [Estimation Model]. 2000. Version 2.15. Washington (DC): U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics; Syracuse (NY): Syracuse Research Corporation. This is an older version of the now available BCFBAF (EPI Suite), described in detail in the Key study on Bioconcentration for Pigment Red 2 of the Naphtol-AS category.

Arnot JA, Gobas FAPC. 2003. A generic QSAR for assessing the bioaccumulation potential of organic chemicals in aquatic food webs. QSAR Comb. Sci. 22(3): 337–345. This model is described in detail in the Key study on Bioconcentration for Pigment Red 2 of the Naphtol-AS category.

[OASIS Forecast] Optimized Approach Based on Structural Indices Set [http://oasis-lmc.org/]. 2005. Version 1.20. Bourgas (BG): Bourgas Prof. Assen Zlatarov University, Laboratory of Mathematical Chemistry. OASIS software forms the basis of the OECD QSAR Toolbox, widely appreciated as reliable instrument for QSAR estimations.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

N-(5-chloro-2,4-dimethoxyphenyl)-4-[[5-[(diethylamino)sulphonyl]-2-methoxyphenyl]azo]-3-hydroxynaphthalene-2-carboxamide

EC Number:

229-107-2

EC Name:

N-(5-chloro-2,4-dimethoxyphenyl)-4-[[5-[(diethylamino)sulphonyl]-2-methoxyphenyl]azo]-3-hydroxynaphthalene-2-carboxamide

Cas Number:

6410-41-9

Molecular formula:

C30H31ClN4O7S

IUPAC Name:

N-(5-chloro-2,4-dimethoxyphenyl)-4-{[5-(diethylsulfamoyl)-2-methoxyphenyl]diazenyl}-3-hydroxy-2-naphthamide

Test material form:

not specified

Details on test material:

Name of test material (as cited in study report): Screening Assessment for the Challenge 2-Naphthalenecarboxamide, N-(5-chloro-2,4-dimethoxyphenyl)-4-[[5- [(diethylamino)sulfonyl]-2-methoxyphenyl]azo]-3-hydroxy- (Pigment Red 5): Pigment Red 5
Analytical purity: Not specified
log Kow = 1.22
SMILES: O=C(Nc(c(OC)cc(OC)c1Cl)c1)c(c(O)c(N=Nc(c(OC)ccc2S(=O)(=O)N(CC)CC)c2)c(c3ccc4)c4)c3

Results and discussion

Bioaccumulation factor

Bioaccumulation factor 1

Type:

BCF

Value:

1.89 L/kg

Basis:

whole body w.w.

Calculation basis:

other: QSAR

Remarks on result:

other: Gobas BCF T2LTL (Arnot & Gobas 2003)

Bioaccumulation factor 2

Type:

BCF

Value:

21.4 L/kg

Basis:

whole body w.w.

Calculation basis:

other: QSAR

Remarks on result:

other: OASIS Forecast, 2005

Bioaccumulation factor 3

Type:

BCF

Value:

10 L/kg

Basis:

whole body w.w.

Calculation basis:

other: QSAR

Remarks on result:

other: BCFWIN v. 2.15, U.S. EPA

Applicant's summary and conclusion

Conclusions:

Three different QSAR models were applied by Environment Canada to assess potential for bioconcentration of Pigment Red 5 in fish. The modelled BCF estimates for Pigment Red 5 are well below 1000 L/kg (log BCF between 0.28 and 1.33, depending on the model).
Pigment Red 5 is therefore expected to present a low bioaccumulation potential, because of its very limited affinity for the lipid phase of living organisms.

Executive summary:

Three different QSAR models were applied by Environment Canada to assess potential for bioconcentration of Pigment Red 5 in fish (reliability category 4 - not assignable, due to missing documentation on input and output parameters for QSAR models). The modelled BCF estimates for Pigment Red 5 are well below 1000 L/kg (log BCF between 0.28 and 1.33, depending on the model).

Pigment Red 5 is therefore expected to present a low bioaccumulation potential, because of its very limited affinity for the lipid phase of living organisms.