Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): C14 component of Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters
- Molecular formula (if other than submission substance): C22 H44 O2
- Molecular weight (if other than submission substance): 340.60
- Smiles notation (if other than submission substance): O=C(OCC(CCCC)CC)CCCCCCCCCCCCC
- Analytical purity: not applicable

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

other: Calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: BCFBAF v3.01
- Result based on calculated log Kow: 9.63 (estimated, KOWWIN v.1.68)

Key result

Type:

BCF

Value:

173 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Regression based estimate

Details on results:

For detailed describtion on the model and its applicability, see "Any other information on materials and methods incl. tables".

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Validated QSAR model. These models have no universally accepted definition of model domain, but since the substance is outside the Kow range of the training set, the results should be taken with caution. The definite values may not be fully reliable, but indicate a low bioaccumulation potential.

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): C14 component of Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters
- Molecular formula (if other than submission substance): C22 H44 O2
- Molecular weight (if other than submission substance): 340.60
- Smiles notation (if other than submission substance): O=C(OCC(CCCC)CC)CCCCCCCCCCCCC
- Analytical purity: not applicable

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

other: Calculation

Water / sediment media type:

natural water: freshwater

Key result

Type:

BAF

Value:

219 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

Key result

Type:

BCF

Value:

3.869 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

Details on results:

For detailed describtion on the model and its applicability, see "Any other information on materials and methods incl. tables".

Estimated Log BCF (mid trophic) = 0.701 (BCF = 5.027 L/kg wet-wt)

Estimated Log BAF (mid trophic) = 2.809 (BAF = 644.8 L/kg wet-wt)

Estimated Log BCF (lower trophic) = 0.737 (BCF = 5.457 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 3.088 (BAF = 1225 L/kg wet-wt)

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

Estimated Log BCF (upper trophic) = 2.283 (BCF = 191.7 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 5.983 (BAF = 9.607e+005 L/kg wet-wt)

Biotransformation Rate Constant:

kM (Rate Constant): 0.1068 /day (10 gram fish)

kM (Rate Constant): 0.06004 /day (100 gram fish)

kM (Rate Constant): 0.03376 /day (1 kg fish)

kM (Rate Constant): 0.01899 /day (10 kg fish)

Bio Half-Life Normalized to 10 g fish at 15 deg C: 6.49 days

Reference 3

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): C16 component of Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters
- Molecular formula (if other than submission substance): C24 H48 O2
- Molecular weight (if other than submission substance): 368.65
- Smiles notation (if other than submission substance): O=C(OCC(CCCC)CC)CCCCCCCCCCCCC
- Analytical purity: not applicable

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

other: Calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: BCFBAF v3.01
- Result based on calculated log Kow: 9.63 (estimated, KOWWIN v.1.68)

Key result

Type:

BCF

Value:

57.2 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Regression based estimate

Details on results:

For detailed describtion on the model and its applicability, see "Any other information on materials and methods incl. tables".

Reference 4

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Validated QSAR model. These models have no universally accepted definition of model domain, but since the substance is outside the Kow range of the training set, the results should be taken with caution. The definite values may not be fully reliable, but indicate a low bioaccumulation potential.

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): C16 component of Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters
- Molecular formula (if other than submission substance): C24 H48 O2
- Molecular weight (if other than submission substance): 368.65
- Smiles notation (if other than submission substance): O=C(OCC(CCCC)CC)CCCCCCCCCCCCC
- Analytical purity: not applicable

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

other: Calculation

Water / sediment media type:

natural water: freshwater

Key result

Type:

BAF

Value:

126 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

Key result

Type:

BCF

Value:

1.475 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

Details on results:

For detailed describtion on the model and its applicability, see "Any other information on materials and methods incl. tables".

Estimated Log BCF (mid trophic) = 0.239 (BCF = 1.733 L/kg wet-wt)

Estimated Log BAF (mid trophic) = 2.342 (BAF = 219.8 L/kg wet-wt)

Estimated Log BCF (lower trophic) = 0.261 (BCF = 1.824 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 2.492 (BAF = 310.2 L/kg wet-wt)

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

Estimated Log BCF (upper trophic) = 1.334 (BCF = 21.56 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 5.021 (BAF = 1.049e+005 L/kg wet-wt)

Example: if needed for discussion you can include the biotransformation rate constant and half-life:

Biotransformation Rate Constant:

kM (Rate Constant): 0.05625 /day (10 gram fish)

kM (Rate Constant): 0.03163 /day (100 gram fish)

kM (Rate Constant): 0.01779 /day (1 kg fish)

kM (Rate Constant): 0.01 /day (10 kg fish)

Bio Half-Life Normalized to 10 g fish at 15 deg C: 12.3 days

Reference 5

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Validated QSAR model. These models have no universally accepted definition of model domain, but since the substance is outside the Kow range of the training set, the results should be taken with caution. The definite values may not be fully reliable, but indicate a low bioaccumulation potential.

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Specific details on test material used for the study:

- SMILES : O=C(OCC(CCCC)CC)CCCCCCCCCCCCCCCCC
- CHEM : C18 FA 2-ethylhexyl ester
- MOL FOR: C26 H52 O2
- MOL WT : 396.70
- Analytical purity: not applicable

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

other: Calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: BCFBAF v3.01
- Result based on calculated log Kow: 9.63 (estimated, KOWWIN v.1.68)

Key result

Type:

BCF

Value:

18.9 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Regression based estimate

Details on results:

For detailed describtion on the model and its applicability, see "Any other information on materials and methods incl. tables".

Reference 6

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Validated QSAR model. These models have no universally accepted definition of model domain, but since the substance is outside the Kow range of the training set, the results should be taken with caution. The definite values may not be fully reliable, but indicate a low bioaccumulation potential.

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Specific details on test material used for the study:

- SMILES : O=C(OCC(CCCC)CC)CCCCCCCCCCCCCCCCC
- CHEM : C18 FA 2-ethylhexyl ester
- MOL FOR: C26 H52 O2
- MOL WT : 396.70
- Analytical purity: not applicable

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

other: Calculation

Water / sediment media type:

natural water: freshwater

Key result

Type:

BAF

Value:

62.75 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

Key result

Type:

BCF

Value:

1.005 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

Details on results:

For detailed describtion on the model and its applicability, see "Any other information on materials and methods incl. tables".

Estimated Log BCF (mid trophic) = 0.036 (BCF = 1.086 L/kg wet-wt)

Estimated Log BAF (mid trophic) = 1.842 (BAF = 69.55 L/kg wet-wt)

Estimated Log BCF (lower trophic) = 0.046 (BCF = 1.111 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 1.872 (BAF = 74.52 L/kg wet-wt)

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

Estimated Log BCF (upper trophic) = 0.485 (BCF = 3.055 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 4.041 (BAF = 1.099e+004 L/kg wet-wt)

Biotransformation Rate Constant:

kM (Rate Constant): 0.02964 /day (10 gram fish)

kM (Rate Constant): 0.01667 /day (100 gram fish)

kM (Rate Constant): 0.009372 /day (1 kg fish)

kM (Rate Constant): 0.00527 /day (10 kg fish)

Bio Half-Life Normalized to 10 g fish at 15 deg C: 23.39 days

Reference 7

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Validated QSAR model. These models have no universally accepted definition of model domain, but since the substance is outside the Kow range of the training set, the results should be taken with caution. The definite values may not be fully reliable, but indicate a low bioaccumulation potential.

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Specific details on test material used for the study:

- SMILES : O=C(OCC(CCCC)CC)CCCCCCCC=CCCCCCCCC
- CHEM : C18 unsatd FA 2-ethylhexyl ester
- MOL FOR: C26 H50 O2
- MOL WT : 394.69
- Analytical purity: not applicable

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

other: Calculation

Water / sediment media type:

natural water: freshwater

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: BCFBAF v3.01
- Result based on calculated log Kow: 9.63 (estimated, KOWWIN v.1.68)

Key result

Type:

BCF

Value:

24.1 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Regression based estimate

Details on results:

For detailed describtion on the model and its applicability, see "Any other information on materials and methods incl. tables".

Reference 8

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Validated QSAR model. These models have no universally accepted definition of model domain, but since the substance is outside the Kow range of the training set, the results should be taken with caution. The definite values may not be fully reliable, but indicate a low bioaccumulation potential.

Principles of method if other than guideline:

Calculation based on BCFBAF v3.01, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Specific details on test material used for the study:

- SMILES : O=C(OCC(CCCC)CC)CCCCCCCC=CCCCCCCCC
- CHEM : C18 unsatd FA 2-ethylhexyl ester
- MOL FOR: C26 H50 O2
- MOL WT : 394.69
- Analytical purity: not applicable

Test organisms (species):

other: Fish

Route of exposure:

aqueous

Test type:

other: Calculation

Water / sediment media type:

natural water: freshwater

Key result

Type:

BAF

Value:

160.9 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

Key result

Type:

BCF

Value:

1.116 L/kg

Basis:

whole body w.w.

Calculation basis:

other: Arnot Gobas (including biotransformation rate estimates, upper trophic)

Details on results:

For detailed describtion on the model and its applicability, see "Any other information on materials and methods incl. tables".

Estimated Log BCF (mid trophic) = 0.093 (BCF = 1.24 L/kg wet-wt)

Estimated Log BAF (mid trophic) = 2.197 (BAF = 157.4 L/kg wet-wt)

Estimated Log BCF (lower trophic) = 0.107 (BCF = 1.281 L/kg wet-wt)

Estimated Log BAF (lower trophic) = 2.192 (BAF = 155.7 L/kg wet-wt)

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

Estimated Log BCF (upper trophic) = 0.647 (BCF = 4.438 L/kg wet-wt)

Estimated Log BAF (upper trophic) = 4.256 (BAF = 1.802e+004 L/kg wet-wt)

Biotransformation Rate Constant:

kM (Rate Constant): 0.02418 /day (10 gram fish)

kM (Rate Constant): 0.0136 /day (100 gram fish)

kM (Rate Constant): 0.007646 /day (1 kg fish)

kM (Rate Constant): 0.0043 /day (10 kg fish)

Bio Half-Life Normalized to 10 g fish at 15 deg C: 28.67 days

Reference 9

Endpoint:

bioaccumulation: aquatic / sediment

Type of information:

other: handbook data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Handbook data

Qualifier:

no guideline followed

Principles of method if other than guideline:

not applicable: handbook data

GLP compliance:

no

Test organisms (species):

other: not applicable

Route of exposure:

other: not applicable

Remarks on result:

other: Not applicable, handbook data.

"Fatty acid degradation and synthesis are relatively simple processes [...]. The process of degradation converts an aliphatic compound into a set of activated acetyl units (acetyl CoA) that can be processed by the citric acid cycle." p.601

"Free fatty acids and monoglycerides are absorbed by intestinal epithelial cells. Triacylglycerols are resynthesized and packaged with other lipids and apoprotein B-48 to form chylomicrons, which are then released into the lymph system [...] and then released into the blood. These particles bind to membrane-bound lipoprotein lipases [...] where the triacylglycerols are once again degraded into free fatty acids and monoglycerol for transport into the tissue. The triacylglycerols are then resynthesized inside the cell and stored." p. 605

Reference 10

Endpoint:

bioaccumulation: aquatic / sediment

Type of information:

other: review article

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented publication which meets basic scientific principles.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Review article describing the metabolism and functions of lipids and fatty acids in fish. Both play major roles as source of metabolic energy in processes as growth and reproduction.

GLP compliance:

no

Test organisms (species):

other: Fish

Route of exposure:

other: not applicable, review article

Test type:

other: not applicable, review article

Remarks on result:

other: The article includes information on the basic biochemistry (distinctions between chain lengths and degree of unsaturation), metabolic processes (biosynthesis and catabolism) and functions of fatty acids (and lipids they are part of)

Remarks:

available for different fish species.

- Fatty acid catabolism is the predominant source of energy in many species of fish. The catabolism of fatty acids occurs in the cellular organelles, mitochondria (and peroxisomes). The process is termed beta-oxidation and involves the sequential cleavage of two-carbon units, released as acetyl-CoA, through a cyclic series of reactions catalyzed by several distinct enzyme activities. Activated fatty acids are transported to the mitochondrion in the form of fatty acyltransferase, converted back into fatty acyl-CoA derivatives, and then undergo a round of dehydrogenation, hydration, second hydrogenation, and cleavage steps to produce acetyl-CoA and NADH. Then, the acetyl-CoA can be metabolized via the tricarboxylic cycle to produce more NADH. The NADH will eventually lead to the release of ATP through the process of oxidative phosphorilation, available to be used as energy source.

- Fatty acid oxidation is an important source of energy in several tissues in fish (heart, red muscles, etc). Furthermore, fatty acids are the major source of metabolic energy in the development from egg to adult fish and also during reproduction and lipid depletion processes, such as migrations. They are also involved in the maintainance of the structure and function of cellular biomembranes (as part of phosphoglycerides).

Description of key information

The BCF of the "isostearate 2 -ethyl-hexyl" estimated with the BCFWin program is between 18.9 to 173 L/kg whole body w.w. (method based on log Kow) when the components with fatty acid chains length between C14 and C18, C18 unsatd. are taken into account. The Arnot-Gobas model gives BCF between 1 to 3.9 L/kg whole body w.w. and BAF between 62.7 to 219 L/kg whole body w.w.

The calculated BCF ≤ 173 L/kg for fish is considered as representative of the registered substance which is not bioaccumulable.

Key value for chemical safety assessment

BCF (aquatic species):

173 L/kg ww

Additional information

No studies investigating the bioaccumulation of “Isostearate 2-ethylhexyl (=Fatty acids, C14-18 and C18 unsatd., branched and linear, 2-ethylhexyl esters (CAS 85186-76-1)) are available. Using the BCFWin program, the BCF values of 173, 57.2, 24.1 and 18.9 L/kg were calculated for the C14, C16,  C18 and C18 unsatd. constituents, respectively (regression method based on log Kow). With this method the components C18 and C18 unsatured, 2-Ethylhexyl esters were outside the application domain. However the log Kow of these 2 components were just above the highest value of the training set with 11.59 and 11.38 compared to the threshold of 11.26. Therefore a very low bioconcentration factor can be anticipated.  

Using the Arnot-Gobas program, which integrates the metabolic transformation in fish and the exposure through the water and the diet, BCF values were found between 3.9 and 1 L/kg and BAF between 63 and 219 L/kg. However the fatty acids C14 to C18, C18 unsatd 2-Ethylhexyl esters are outside the Kow range of the training set. So these results should be taken with caution. The definite values may not be fully reliable, however confirm a very low bioconcentration and bioaccumulation potential.

The branched chains were not taken into account because no precise information on these structures are available. Nevertheless simulation done with the BCFWin program can demonstrate that the branching of the alkyl chain has very little impact on the BCF.

It can be assumed that the BCF of the Isostearate 2-ethylhexyl is low and can be represented by the calculated value ≤ 173 L/kg.