Registration Dossier

Administrative data

Endpoint:
bioaccumulation: aquatic / sediment
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2010
Reliability:
2 (reliable with restrictions)

Data source

Reference
Reference Type:
other: modeling
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The BCFBAF Program is an update and expansion of the previous BCFWIN Program that was part of the EPI Suite version 3.20.  The update pertains to estimation of Bioconcentration Factor (BCF).  The BCFBAF program estimates BCF of an organic compound using the compound's log octanol-water partition coefficient (Kow).  For the update, a more recent and better evaluated database of BCF values was used for both training and validation.  The BCF data were re-regressed using the same methodology as in the original BCFWIN program.

The original estimation methodology used by the original BCFWIN program is described in a document prepared for the U.S. Environmental Protection Agency (Meylan et al., 1997).  The estimation methodology was then published in journal article (Meylan et al, 1999).  The methodology is described in the Bioconcentration Factor Estimation section.

BCFBAF has been expanded to include estimation of the Biotransformation Rate (kM) in fish and estimation of Bioaccumulation Factor (BAF) by the Arnot-Gobas method (Arnot and Gobas, 2003).

BCFBAF requires only a chemical structure to estimate BCF, BAF and kM.  Structures are entered into BCFBAF through SMILES (Simplified Molecular Input Line Entry System) notations.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
not relevant
Radiolabelling:
no

Sampling and analysis

Details on sampling:
not relevant

Test solutions

Details on preparation of test solutions, spiked fish food or sediment:
not relevant

Test organisms

Test organisms (species):
no data
Details on test organisms:
not relevant

Study design

Route of exposure:
other: no data
Test type:
not specified
Water / sediment media type:
not specified

Test conditions

Nominal and measured concentrations:
no data
Reference substance (positive control):
not specified
Details on estimation of bioconcentration:
The original estimation methodology used by the original BCFWIN program is described in a document prepared for the U.S. Environmental Protection Agency (Meylan et al., 1997).  The estimation methodology was then published in journal article (Meylan et al, 1999).

The BCFBAF Program updates the BCF estimation methodology of the BCFWIN program by using an updated and better evaluated BCF database for selecting training and validation datasets.  The exact same regression methodology used to derive the original BCFWIN method was used to derive the BCFBAF method for estimating BCF.

Experimental BCF Data
The measured BCF values used in the revised regressions were selected from a quality reviewed BCF database (Arnot and Gobas, 2006); details of the data quality review methods are described in Arnot and Gobas (2006).  Single BCF values were selected for each compound (median values were generally selected for compounds with multiple values).

The BCF values selected for the BCFBAF training and validation datasets are available via Internet download at: http://esc.syrres.com/interkow/EpiSuiteData.htm

Estimation Methodology

The following is a brief summary of the estimation methodology:

The BCFBAF method classifies a compound as either ionic or non-ionic.  Ionic compounds include carboxylic acids, sulfonic acids and salts of sulfonic acids, and charged nitrogen compounds (nitrogen with a +5 valence such as quaternary ammonium compounds).  All other compounds are classified as non-ionic.

Training Dataset Included:

466 Non-Ionic Compounds
61  Ionic Compounds (carboxylic acids, sulfonic acids, quats)

Methodology for Non-Ionic was to separate compounds into three divisions by Log Kow value as follows:
Log Kow  <  1.0
Log Kow  1.0  to  7.0
Log Kow  > 7.0

Results and discussion

Bioaccumulation factoropen allclose all
Type:
BCF
Value:
178.4 L/kg
Basis:
not specified
Remarks on result:
other: Conc.in environment / dose:no data
Type:
BCF
Value:
1 764 dimensionless
Basis:
not specified
Remarks on result:
other: Conc.in environment / dose:no data

Any other information on results incl. tables

Estimation Methodology

The Arnot-Gobas BCF and BAF model(Arnot and Gobas, 2003)

The Arnot-Gobas model estimates steady-state bioconcentration factor (BCF; L/kg) and bioaccumulation factor (BAF; L/kg) values for non-ionic organic chemicals in three general trophic levels of fish (i.e., lower, middle and upper) in temperate environments. The model calculations represent general trophic levels (i.e., not for a particular fish species) and are derived for representative environmental conditions (e.g., dissolved and particulate organic carbon content in the water column, water temperature). Thus, it provides general estimates for these conditions in absence of site-specific measurements or estimates. The default temperature for the BCF and BAF calculations is 10oC (temperate regions); therefore, the model predictions are not recommended for arctic, sub-tropical or tropical regions or for comparisons with other vastly different conditions (e.g., laboratory tests at ~25oC). Site-specific food web models, bioaccumulation models and bioconcentration models are available for specific modeling requirements (e.g.,http://www.rem.sfu.ca/toxicology/models/models.htm,http://www.trentu.ca/cemc).

The model includes mechanistic processes for bioconcentration and bioaccumulation such as chemical uptake from the water at the gill surface (BCFs and BAFs) and the diet (BAFs only), and chemical elimination at the gill surface, fecal egestion, growth dilution and metabolic biotransformation (Arnot and Gobas 2003). Other processes included in the calculations are bioavailability in the water column (only the freely dissolved fraction can bioconcentrate) and absorption efficiencies at the gill and in the gastrointestinal tract. The model requires the octanol-water partition coefficient (KOW) of the chemical and the normalized whole-body metabolic biotransformation rate constant (kM, N; /day) as input parameters to predict BCF and BAF values. The requiredkM, Nvalue must be normalized to a fish of 10 g (Arnot et al., 2008). Model predictions may be highly uncertain for chemicals that have estimated log KOWvalues > 9. The model is not recommended at this time for chemicals that appreciably ionize, for pigments and dyes, or for perfluorinated substances.

The BAF calculations were derived from the parameterization and calibration of the model to a large database of measured BAF values from the Great Lakes (Lake Ontario, Lake Erie and Lake St. Clair).The measured BAFs are for chemicals that are poorly metabolized (e.g., PCBs) and were generally grouped into lower, middle and upper trophic levels of fish species. The overall food web biomagnification factors (β) in the BAF model are calibrated to each trophic level of measured BAF values (Arnot and Gobas, 2003). Therefore, in the absence of metabolic biotransformation the BAF model predictions are in general agreement with measured BAFs in fish of these general trophic positions from the Great Lakes for chemicals that are poorly metabolized.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
Based on this statistical assessment, Amines, N-tallow alkyltrimethylenedi-, propoxylated is not considered to be bioaccumulable.
Executive summary:

No actual figures are available for characterizing bioaccumulation potential for Amines, N-tallow alkyltrimethylenedi-, propoxylated. In order to address the data gap, modeling approach is proposed introducing actual value for Log Pow which has been determined to be >6.0. The maximum estimated BCF is 1764 indicating that Amines, N-tallow alkyltrimethylenedi-, propoxylated would not bioaccumulate in organism tissues.