Reaction mass of dipentene and (Z)-3,7-dimethylocta-1,3,6,-triene

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:

June 2021

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:

Episuite and the BCFBAF models are well documented and commonly used QSARs for predicting the bioaccumulation potential of chemicals. Substances within LOA fall within the applicability domain of these models and they have been recommended by ECHA in the Information Requirement Guidelines.

Qualifier:

no guideline required

Principles of method if other than guideline:

Formerly called BCFWIN, the BCFBAF program estimates fish bioconcentration factor (BCF) and its logarithm using two different methods. The first is the traditional regression based on log KOW plus any applicable correction factors. The second is the Arnot-Gobas method, which calculates BCF from mechanistic first principles. BCFBAF also incorporates prediction of apparent metabolism half-life in fish, and estimates BCF and BAF for three trophic levels. The program is based on methodologies developed by Arnot-Gobas et al. (2003, 2006, 2008). A 5% lipid normalisation has been used for the Arnot-Gobas method BCF values, as recommended in OECD TG 305.

Specific details on test material used for the study:

Consituents that were included in this QSAR prediction
# CAS Number SMILES
(Z)-3,7-dimethylocta-1,3,6,-triene / 3,7-dimethylocta-1,3,6-triene 3338-55-4 CC(C)=CC\C=C(\C)C=C
1-methyl-4-(prop-1-en-2-yl)cyclohexene 138-86-3 CC(=C)C1CCC(C)=CC1
2,6-dimethylocta-2,4,6-triene / 2,6-dimethylocta-2,4,6-triene 673-84-7 C\C=C(/C)\C=C\C=C(C)C
(E)-3,7-dimethylocta-1,3,6-triene / 3,7-dimethylocta-1,3,6-triene 3779-61-1 CC(C)=CC\C=C(/C)C=C

Radiolabelling:

no

Key result

Type:

BCF

Value:

>= 363 - <= 676

Basis:

whole body d.w.

Calculation basis:

other: based on log Kow regression

Remarks on result:

other: based on log Kow regression

Key result

Type:

BCF

Value:

>= 426 - <= 890 L/kg

Basis:

whole body d.w.

Calculation basis:

other: based on Arnot Gobas upper trophic with 5% lipid correction

Remarks on result:

other: based on Arnot Gobas upper trophic with 5% lipid correction

Results from QSAR

Consituent	CAS Number	SMILES	BCF (L/kg)	BCF (upper trophic) L/kg 5% lipid correction
(Z)-3,7-dimethylocta-1,3,6,-triene / 3,7-dimethylocta-1,3,6-triene	3338-55-4	CC(C)=CC\C=C(\C)C=C	676	890
1-methyl-4-(prop-1-en-2-yl)cyclohexene	138-86-3	CC(=C)C1CCC(C)=CC1	363	426
2,6-dimethylocta-2,4,6-triene / 2,6-dimethylocta-2,4,6-triene	673-84-7	C\C=C(/C)\C=C\C=C(C)C	603	976
(E)-3,7-dimethylocta-1,3,6-triene / 3,7-dimethylocta-1,3,6-triene	3779-61-1	CC(C)=CC\C=C(/C)C=C	676	890

Conclusions:

The estimated BCF for the consituents in this substance range from 426 to 890 L/kg (highest value of the Arnot-Gobas (upper trophic with 5% lipid normalisation).

Executive summary:

The bioconcentration factor (BCF) value has been estimated using the EPISUITE v4.11 BCFBAF (2010) model.. The estimated BCF for the consituents in this substance range from 426 to 890 L/kg (highest value of the Arnot-Gobas (upper trophic with 5% lipid normalisation).

Description of key information

The bioconcentration factor (BCF) value has been estimated using the EPISUITE v4.11 BCFBAF (2010) model.. The estimated BCF for the consituents in this substance range from 426 to 890 L/kg (highest value of the Arnot-Gobas (upper trophic with 5% lipid normalisation).

Key value for chemical safety assessment

BCF (aquatic species):

890 L/kg ww