Registration Dossier

Environmental fate & pathways

Bioaccumulation: aquatic / sediment

Currently viewing:

Administrative data

Endpoint:
bioaccumulation: aquatic / sediment
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
supporting study
Study period:
2008
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.

Data source

Reference
Reference Type:
other: Environmental Agency Assessment Report
Title:
Screening Assessment for the Challenge 4-[[5-[[[4-(Aminocarbonyl)phenyl]amino]carbonyl]-2-methoxyphenyl]azo]-N-(5-chloro-2,4-dimethoxyphenyl)-3-hydroxynaphthalene-2-carboxamide (Pigment Red 187)
Author:
Environment Canada, Health Canada
Year:
2008
Bibliographic source:
http://www.ec.gc.ca/ese-ees/default.asp?lang=En&n=DF97D5A1-1

Materials and methods

Principles of method if other than guideline:
QSAR estimation of fish BCF for Pigment Red 187 and, as close analogue Pigment Red 146 (CAS 5280-68-2). As this endpoint study record refers to Pigment Red 146 only, data on Pigment Red 187 are not reported here (see corresponding substance of the Naphtol-AS category).

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 146 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 new set of BCF estimates for Pigment Red 146 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 1.1. This is in agreement with the value reported in IUCLID section 4.7 for Pigment Red 146 (1.06).

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 for Bioconcentration for Pigment Red 2.

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 for Bioconcentration for Pigment Red 2.

[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.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
CAS: 5280-68-2
log Kow = 1.1
SMILES: COc1cc(NC(=O)c2cc3ccccc3c(N=Nc3cc(ccc3OC)C(=O)Nc3ccccc3)c2O)c(OC)cc1Cl

Results and discussion

Bioaccumulation factoropen allclose all
Type:
BCF
Value:
1.46 L/kg
Basis:
whole body w.w.
Calculation basis:
other: QSAR
Remarks on result:
other: Gobas BCF T2LTL (Arnot & Gobas 2003)
Type:
BCF
Value:
19.2 L/kg
Basis:
whole body w.w.
Calculation basis:
other: QSAR
Remarks on result:
other: OASIS Forecast, 2005
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 146 in fish. The modelled BCF estimates for Pigment Red 146 are well below 1000 L/kg (log BCF between 0.16 and 1.28, depending on the model).
Pigment Red 146 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 146 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 146 are well below 1000 L/kg (log BCF between 0.16 and 1.28, depending on the model).

Pigment Red 146 is therefore expected to present a low bioaccumulation potential, because of its very limited affinity for the lipid phase of living organisms.