D-Xylopyranose, oligomeric, 2-octyldodecyl xylosides

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

04/14/2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
EPI Suite v4.11

2. MODEL (incl. version number)
BCFBAF (BCFWIN) v3.02

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
O1CC(O)C(O)C(O)C1OCC(CCCCCCCC)CCCCCCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See the QMRF and QPRF attached documents in the section "attached justification"
- Defined endpoint: Environmental fate: Bioconcentration (BCF) in fish (log BCF) (unitless)
- Unambiguous algorithm: See the QMRF and QPRF attached documents in the section "attached justification"
- Defined domain of applicability: See the QMRF and QPRF attached documents in the section "attached justification"
The model 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.
Therefore, the test item as a polyalcohol is considered as a non-ionic compound by the model
for both descriptors.
- Appropriate measures of goodness-of-fit and robustness and predictivity: No uncertainty measure is given for the prediction.
- Mechanistic interpretation:Log KOW is considered to be the key parameter explaining the transfer from water to the lipidic phase of the fish cell. The assumption is that bioconcentration is a thermodynamically driven partitioning process between water and the lipid phase of the exposed organism, and therefore can be modeled using n-octanol as a surrogate for biological lipids.

5. APPLICABILITY DOMAIN
See the QMRF and QPRF attached documents in the section "attached justification"

6. ADEQUACY OF THE RESULT
The test item falls within the applicability domain of the model and was therefore reliably predicted for its log BCF.

Qualifier:

according to guideline

Guideline:

other: OECD (2004). Principles for the validation, for regulatory purposes, of (Quantitative) Structure Activity-Relationship Models.

Deviations:

not applicable

GLP compliance:

no

Radiolabelling:

not specified

Vehicle:

not specified

Test organisms (species):

other: Not applicable, QSAR calculation

Route of exposure:

other: Not applicable, QSAR calculation

Justification for method:

other: Not applicable, QSAR calculation

Test type:

not specified

Total exposure / uptake duration:

ca. 28 d

Total depuration duration:

ca. 14 d

Key result

Type:

BCF

Value:

ca. 1 555 L/kg

Basis:

whole body w.w.

The test item falls within the descriptor domain of the model (Molecular weight = 430.66 g/mol and log Kow = 7.69 at 25°C). 

log BCF of the test item was predicted as 3.19 (1555 L/kg (wet weight)).

Validity criteria fulfilled:

not applicable

Conclusions:

The log BCF of the test item was predicted as 3.19 (BCF = 1.55E+03 L/kg (wet weight)).
The test item falls within the applicability domain of the model and was therefore reliably predicted
for its log BCF.

Description of key information

The log BCF has been predicted using the model BCFBAF (v3.02) from EPI Suite software (v4.11) which provides a quantitative prediction of bioconcentration factor (BCF) of the test substance in fish or specified tissues thereof divided by the concentration of the chemical in the surrounding medium at steady state.

The log BCF is calculated as follows: 3.19.

Key value for chemical safety assessment

BCF (aquatic species):

1 550 L/kg ww