C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: BCF estimated using a Log Kow calculated from octanol and water solubility data. The training set of the model does however only contain a limited number of cationic substances.

Justification for type of information:

QSAR prediction:

Qualifier:

no guideline followed

Principles of method if other than guideline:

The BCFBAF Program is an update and expansion of the previous BCFWIN Program that was part of the EPI Suite version 3.20. The update pertains to estimation of Bioconcentration Factor (BCF). The BCFBAF program estimates BCF of an organic compound using the compound's log octanol-water partition coefficient (Kow). For the update, a more recent and better evaluated database of BCF values was used for both training and validation. The BCF data were re-regressed using the same methodology as in the original BCFWIN program.

GLP compliance:

no

Radiolabelling:

no

Key result

Type:

BCF

Value:

41 L/kg

BCFBAF Program (v3.01) Results:

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

SMILES : CCCCCCCCC=CCCCCCCCCN(CCO)(CCO)(=O)

CHEM   : C18= alkyl bis(2-hydroxyethyl) amine oxide

MOL FOR: C22 H45 N1 O3

MOL WT : 371.61

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

Summary Results:

 Log BCF (regression-based estimate):  1.61  (BCF = 41.1 L/kg wet-wt)

 Biotransformation Half-Life (days) :  0.17  (normalized to 10 g fish)

 Log BAF (Arnot-Gobas upper trophic):  1.60  (BAF = 39.6 L/kg wet-wt)

Log Kow (experimental):  not available from database

Log Kow used by BCF estimates:  2.95 (user entered)

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 =  1.613  (BCF = 41.06 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 |  2  |  Aliphatic alcohol  [-OH]                  | -0.0616 | -0.1231

Frag |  1  |  Methyl  [-CH3]                            |  0.2451 |  0.2451

Frag | 19  |  -CH2-  [linear]                           |  0.0242 |  0.4596

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

Frag |  1  |  Quaternary amine                          |  0.0000 |  0.0000

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

L Kow|  *  |  Log Kow =   2.95 (user-entered   )        |  0.3073 |  0.9067

MolWt|  *  |  Molecular Weight Parameter                |         | -0.9529

Const|  *  |  Equation Constant                         |         | -1.5371

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

  RESULT   |        LOG Bio Half-Life (days)            |         | -0.7700

  RESULT   |            Bio Half-Life (days)            |         |  0.1698

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

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

Biotransformation Rate Constant:

kM (Rate Constant):  4.081 /day (10 gram fish)

kM (Rate Constant):  2.295 /day (100 gram fish)

kM (Rate Constant):  1.291 /day (1 kg fish)

kM (Rate Constant):  0.7258 /day (10 kg fish)

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

  Estimated Log BCF (upper trophic) =  1.598  (BCF = 39.61 L/kg wet-wt)

  Estimated Log BAF (upper trophic) =  1.598  (BAF = 39.61 L/kg wet-wt)

  Estimated Log BCF (mid trophic)   =  1.571  (BCF = 37.24 L/kg wet-wt)

  Estimated Log BAF (mid trophic)   =  1.571  (BAF = 37.25 L/kg wet-wt)

  Estimated Log BCF (lower trophic) =  1.551  (BCF = 35.56 L/kg wet-wt)

  Estimated Log BAF (lower trophic) =  1.551  (BAF = 35.6 L/kg wet-wt)

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

  Estimated Log BCF (upper trophic) =  1.982  (BCF = 95.93 L/kg wet-wt)

  Estimated Log BAF (upper trophic) =  2.033  (BAF = 107.9 L/kg wet-wt)

Validity criteria fulfilled:

not applicable

Remarks:

QSAR calculation

Conclusions:

QSAR calculation of the BCF using an estimated log Kow based on measured water and octanol solubility data. The Log Kow is currently considered to be a poor predicter of the bioaccumulation potential of cationic surfactants. The fate of amineoxides in that perspective is even less clear.
C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide is however readilty biodegradable and is similar to the primary alkyl amines, diamine and primary alkylamine ethoxylates (2EO) expected to be rapidly metabolized in fish. BCFBAF estimates a half-life in fish of 0.17 days (normalized to 10 g fish)

Executive summary:

EPI suite calculations based on a measured log Kow of 2.95 at 23 C (pH 7) predict a log BCF of 41(regression based).

Description of key information

A  log Kow value of 2.95 is measured using the ratio of the solubility in Octanol and the CMC (as surogate for the solubility in water) at pH 7 and 23 C indicating a low bioaccumulation potential for C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide( CAS no.: 61791 -46 -6). The Log Kow is currently considered to be a poor predicter of the bioaccumulation potential of cationic surfactants.  

C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide is however readily biodegradable and is similar to the primary alkyl amines, diamine and primary alkylamine ethoxylates (2EO) expected to be rapidly metabolized in fish. BCFBAF estimates a half-life in fish of 0.17 days (normalized to 10 g fish)

The substance is readily biodegradable and is expected to be rapidly biotransformed by fish liver S9 fractions it is therefore unlikely that it will accumulate in the food chain.  

Key value for chemical safety assessment

BCF (aquatic species):

41 L/kg ww

Additional information

With a log Kow of 2.95 the BCFBAF model predicts a BCF of 41.1 L/kg wwt (regression based).

The calculated BCF value of 41.1 indicates that C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide has a low to moderate bioaccumulation potential. The Log Kow is currently considered to be a poor predicter of the bioaccumulation potential of cationic surfactants.

C16-18 (evennumbered, C18 unsaturated) alkyl bis(2-hydroxyethyl) amine oxide is however readily biodegradable and is similar to the primary alkyl amines, diamine and primary alkylamine ethoxylates (2EO) expected to be rapidly metabolized in fish. BCFBAF estimates a half-life in fish of 0.17 days (normalized to 10 g fish)