Methyl 12-hydroxyoctadecanoate

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Remarks:

BCFBAF v3.01

Adequacy of study:

key study

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:

Modeling report of BCFBAF v3.01, a model contained within EPI-Suite version 4.11, a reliable QSAR model.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Parameter estimation by QSAR, using BCFBAF v3.01, a model within EPI Suite version 4.11, from the U.S. Environmental Protection Agency (EPA), a validated QSAR program which is part of the OECD (Q)SAR Toolbox.

GLP compliance:

no

Remarks:

not applicable

Key result

Type:

BCF

Value:

511 L/kg

Basis:

whole body w.w.

Calculation basis:

other:

Remarks:

QSAR prediction estimated using modeling report of BCFBAF v 3.01, a model contained within EPI-Suite v 4.11, a reliable (Q)SAR model.

Type:

BAF

Value:

83.7 L/kg

Calculation basis:

other:

Remarks:

QSAR prediction estimated using modeling report of BCFBAF v 3.01, a model contained within EPI-Suite v 4.11, a reliable (Q)SAR model.

Type:

other: Log BCF

Value:

2.708 dimensionless

Basis:

whole body w.w.

Calculation basis:

other:

Remarks:

QSAR prediction estimated using modeling report of BCFBAF v 3.01, a model contained within EPI-Suite v 4.11, a reliable (Q)SAR model.

An BCFBAF Program (v3.01) Results:

==============================

SMILES : O=C(OC)CCCCCCCCCCC(O)CCCCCC

CHEM : Octadecanoic acid, 12-hydroxy-, methyl ester

MOL FOR: C19 H38 O3

MOL WT : 314.51

--------------------------------- BCFBAF v3.01 --------------------------------

Summary Results:

Log BCF (regression-based estimate): 2.71 (BCF = 511 L/kg wet-wt)

Biotransformation Half-Life (days) : 0.386 (normalized to 10 g fish)

Log BAF (Arnot-Gobas upper trophic): 1.92 (BAF = 83.7 L/kg wet-wt)

Log Kow (experimental): not available from database

Log Kow used by BCF estimates: 6.69

Equation Used to Make BCF estimate:

Log BCF = 0.6598 log Kow - 0.333 + Correction

Correction(s): Value

Alkyl chains (8+ -CH2- groups) -1.374

Estimated Log BCF = 2.708 (BCF = 510.9 L/kg wet-wt)

===========================================================

Whole Body Primary Biotransformation Rate Estimate for Fish:

===========================================================

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Linear C4 terminal chain [CCC-CH3] | 0.0341 | 0.0341

Frag | 1 | Aliphatic alcohol [-OH] | -0.0616 | -0.0616

Frag | 1 | Ester [-C(=O)-O-C] | -0.7605 | -0.7605

Frag | 2 | Methyl [-CH3] | 0.2451 | 0.4902

Frag | 15 | -CH2- [linear] | 0.0242 | 0.3628

Frag | 1 | -CH- [linear] | -0.1912 | -0.1912

L Kow| * | Log Kow = 6.69 (KowWin estimate) | 0.3073 | 2.0569

MolWt| * | Molecular Weight Parameter | | -0.8065

Const| * | Equation Constant | | -1.5371

============+============================================+=========+=========

RESULT | LOG Bio Half-Life (days) | | -0.4129

RESULT | Bio Half-Life (days) | | 0.3865

NOTE | Bio Half-Life Normalized to 10 g fish at 15 deg C |

============+============================================+=========+=========

Biotransformation Rate Constant:

kM (Rate Constant): 1.794 /day (10 gram fish)

kM (Rate Constant): 1.009 /day (100 gram fish)

kM (Rate Constant): 0.5672 /day (1 kg fish)

kM (Rate Constant): 0.319 /day (10 kg fish)

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

Estimated Log BCF (upper trophic) = 1.908 (BCF = 80.84 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 1.923 (BAF = 83.72 L/kg wet-wt)

Estimated Log BCF (mid trophic) = 2.045 (BCF = 110.8 L/kg wet-wt)

Estimated Log BAF (mid trophic) = 2.375 (BAF = 236.9 L/kg wet-wt)

Estimated Log BCF (lower trophic) = 2.087 (BCF = 122.1 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 3.036 (BAF = 1088 L/kg wet-wt)

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

Estimated Log BCF (upper trophic) = 4.210 (BCF = 1.624e+004 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 6.957 (BAF = 9.062e+006 L/kg wet-wt)

Validity criteria fulfilled:

yes

Remarks:

Validated QSAR, part of the OECD (Q)SAR Toolbox

Conclusions:

The estimated log BCF for 12-HSA ME was 2.708 (estimated BCF = 510.9 L/kg wet weight).

Description of key information

The bioconcentration factor (BCF) was estimated by BCFBAF v3.01, a model within Estimation Programs Interface Suite™ for Microsoft ® Windows, v4.11. This estimated BCF is useful to evaluate the potential for bioaccumulation in aquatic habitats. The estimated log BCF for the substance was 2.71 (estimated BCF = 511 L/kg wet weight).

There is uncertainty associated with the predicted BCF value (since the octanol-water partition coefficient for the substance, which was reported as log Kow = 6.69, is greater than log Kow = 6); nevertheless, further information on bioaccumulation is not indicated by the Integrated Testing Strategy. Although the predicted BCF of 511 L/kg w.w. is below the threshold for both bioaccumulative (BCF > 2000 L/kg w.w.) and very bioaccumulative (BCF > 5000 L/kg w.w.), assuming the substance is potentially bioaccumulative does not affect the PBT and vPvB determinations. Similarly, the environmental classification of the substance was based upon the octanol-water partition coefficient for the substance (which was reported as log Kow = 6.69, and is greater than or equal to log Kow of 4); thus, the absence of an experimentally determined BCF value does not affect the environmental classification of the substance. 

Key value for chemical safety assessment

BCF (aquatic species):

511 L/kg ww