Oct-2-ene

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Remarks:

QSAR BCFBAF v3.01

Adequacy of study:

supporting 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:

439.2 L/kg

Basis:

other:

Remarks:

BCFBAF v3.01 prediction.

Calculation basis:

other:

Remarks:

(Q)SAR prediction.

Remarks on result:

other:

Remarks:

Bioconcentration Factor based on QSAR/QSPR prediction.

BCFBAF Program (v3.01) Results:

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

SMILES : C(=CC)CCCCC

CHEM  : 2-Octene

MOL FOR: C8 H16

MOL WT : 112.22

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

Summary Results:

 Log BCF (regression-based estimate): 2.64 (BCF = 439 L/kg wet-wt)

 Biotransformation Half-Life (days) : 2.6 (normalized to 10 g fish)

 Log BAF (Arnot-Gobas upper trophic): 2.91 (BAF = 822 L/kg wet-wt)

 

Log Kow (experimental): 4.51

Log Kow used by BCF estimates: 4.51

 

Equation Used to Make BCF estimate:

  Log BCF = 0.6598 log Kow - 0.333 + Correction

 

     Correction(s):                   Value

      No Applicable Correction Factors

 

  Estimated Log BCF = 2.643 (BCF = 439.2 L/kg wet-wt)

 

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

Whole Body Primary Biotransformation Rate Estimate for Fish:

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

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

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

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

 Frag | 2 | Linear C4 terminal chain [CCC-CH3]      | 0.0341 | 0.0682

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

 Frag | 4 | -CH2- [linear]                          | 0.0242 | 0.0967

 Frag | 2 | -C=CH [alkenyl hydrogen]                | 0.0988 | 0.1977

 Frag | 2 | -C=CH [alkenyl hydrogen]                | 0.0000 | 0.0000

 L Kow| * | Log Kow =  4.51 (experimental  )       | 0.3073 | 1.3861

 MolWt| * | Molecular Weight Parameter               |        | -0.2878

 Const| * | Equation Constant                        |        | -1.5371

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

  RESULT  |       LOG Bio Half-Life (days)           |        | 0.4142

  RESULT  |           Bio Half-Life (days)           |        |  2.595

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

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

 

Biotransformation Rate Constant:

 kM (Rate Constant): 0.2671 /day (10 gram fish)

 kM (Rate Constant): 0.1502 /day (100 gram fish)

 kM (Rate Constant): 0.08446 /day (1 kg fish)

 kM (Rate Constant): 0.04749 /day (10 kg fish)

 

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

  Estimated Log BCF (upper trophic) = 2.910 (BCF = 813.1 L/kg wet-wt)

  Estimated Log BAF (upper trophic) = 2.915 (BAF = 822 L/kg wet-wt)

  Estimated Log BCF (mid trophic)  = 2.946 (BCF = 882.2 L/kg wet-wt)

  Estimated Log BAF (mid trophic)  = 2.969 (BAF = 930.4 L/kg wet-wt)

  Estimated Log BCF (lower trophic) = 2.945 (BCF = 880.8 L/kg wet-wt)

  Estimated Log BAF (lower trophic) = 3.005 (BAF = 1011 L/kg wet-wt)

 

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

  Estimated Log BCF (upper trophic) = 3.492 (BCF = 3107 L/kg wet-wt)

  Estimated Log BAF (upper trophic) = 4.202 (BAF = 1.591e+004 L/kg wet-wt)

 

Validity criteria fulfilled:

yes

Remarks:

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

Conclusions:

The estimated log BCF for Oct-2-ene was 2.643 (estimated BCF = 439.2 L/kg wet weight) indicating that this substance does not have the potential for bioaccumulation and can be considered "not bioaccumulative".

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: TGD guideline, QSAR calculation, acceptable with restrictions

Justification for type of information:

Read-across between the target substance Oct-2-ene (EC 203-894-2 / CAS 111-67-1) and source substances Octene (EC 246-920-8 / CAS 25377-83-7) and Oct-1-ene (EC 203-893-7 / CAS 111-66-0 / alpha-C8) is based upon the similarity of the chemical structures and their respective physico-chemical properties. The ECHA Read-Across Assessment Framework (RAAF) states that substances with qualitatively similar properties can form the basis of read-across in circumstances where the source and target substances share such similar characteristics.
Octene, Oct-1-ene and Oct-2-ene are linear olefins, each with a carbon chain length of C8. Structurally, the difference between source and target substances is the position of the carbon-carbon double bond. For Oct-1-ene the double bond is at the terminal C1 position (hence, an alpha-olefin), whereas for Oct-2-ene the double bond is at the non-terminal C2 position (hence, an internal olefin). A comparison of the target and source substance properties shows that both substances would be expected to exhibit similar environmental fate, ecotoxicological and mammalian toxicological behaviours. The justification for this read-across from source substances Octene and Oct-1-ene to target substance Oct-2-ene is detailed in section 13 (Document name: “Oct-2-ene Read Across Document HOPA”).
Further, Oct-2-ene and Oct-1-ene both fit within the boundaries of the chemical category of higher olefins. Studies conducted by the HOPA consortium on a large range of higher olefin category members (including Oct-1-ene) demonstrated sufficiently similar physico-chemical, environmental fate and toxicological properties to substantiate the basis for read-across. Therefore Oct-2-ene is expected to behave similarly. Justification for inclusion of Oct-2-ene within the boundaries of the higher olefins category, and the relevance of each category member as an analogue substance to Oct-2-ene, is provided in Section 13 (Document name: “HOPA Higher Olefins CJD with Category Matrix Report [rev 1 Sept 2016]”).

Reason / purpose for cross-reference:

read-across: supporting information

Principles of method if other than guideline:

This model uses a linear relationship between log Kow and BCF to predict the BCF of a test substance. This linear relationship applies to substances with a log Kow <6. The linear model has been validated using a dataset other than the training dataset.

GLP compliance:

no

Remarks:

not applicable

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not applicable

Details on sampling:

not applicable

Vehicle:

no

Details on preparation of test solutions, spiked fish food or sediment:

not applicable

Test organisms (species):

Pimephales promelas

Details on test organisms:

not applicable

Route of exposure:

aqueous

Test type:

not specified

Water / sediment media type:

natural water: freshwater

Hardness:

not applicable

Test temperature:

not applicable

pH:

not applicable

Dissolved oxygen:

not applicable

TOC:

not applicable

Salinity:

not applicable

Details on test conditions:

not applicable

Nominal and measured concentrations:

not applicable

Details on estimation of bioconcentration:

not applicable

Type:

other: log BCF

Value:

2.74 dimensionless

Basis:

not specified

Remarks on result:

other: based on a log Kow 4.05

Details on kinetic parameters:

not applicable

Metabolites:

not applicable

Results with reference substance (positive control):

not applicable

Details on results:

not applicable

Reported statistics:

not applicable

Validity criteria fulfilled:

not applicable

Conclusions:

The calculated log BCF is 2.74.

Executive summary:

An experimental BCF is not available for octene. In the absence of measured data the use of a QSAR to predict the BCF is an appropriate technique to use. The use of the linear bioconcentration factor for aquatic organisms QSAR recommended in the Technical Guidance Document (2003) is appropriate for octene as its log Kow falls within the applicability domain of the model.

Additional information

The bioconcentration factor (BCF) was estimated by the use of two QSAR models. The estimated BCF of teh substance was predicted by BCFBAF v3.01, a model within Estimation Programs Interface Suite™ for Microsoft ® Windows, v4.11 and an experimentally determined log Kow of 4.51 provied by EPI Suite. The estimated log BCF for Oct-2-ene was 2.643 (estimated BCF = 439.2 L/kg wet weight) indicating that this substance is not predicted to be bioaccumulative.

A supporting EPI-Suite model conducted for octene (C8) used an input value of log Kow = 4.05; the predicted value for BCF was similar (i.e., log BCF = 2.74, BCF = 550 L/kg w.w.).