2-ethylhexylamine

Bioaccumulation: aquatic / sediment

Description of key information

Based on the substance's log Kow and weight-of-evidence approach by calculated data, significant accumulation in organisms is not to be expected.

Key value for chemical safety assessment

BCF (aquatic species):

24.9 L/kg ww

Additional information

With regard to the log Kow of the test substance, accumulation in organisms is not to be expected. The log Kow of the uncharged molecule was estimated to be 2.73 (EPI Suite v4.11, KOWWIN v1.68). The experimentally determined log Kow is 2.82 (Hansch et al., 1995; see IUCLID Ch. 4.7). Both log Kow values indicate a low bioaccumulation potential for the uncharged molecule. In accordance with column 2 of REACH Annex IX, the study does not need to be conducted since the substance has a log Kow less or equal than 3.

However, in order to assess the bioaccumulation potential of the test substance, the BCF substance was calculated with several estimation models. The table below lists the applied (Q)SAR models, the estimated BCF values and basic information on the applicability domain (AD). Detailed information on the model’s results and the AD are given in the endpoint study records of IUCLID Chapter 5.3.1. The selected models comply with the OECD principles for (Q)SAR models.

Considering all models applied the estimated BCF values range from 10 to 136 L/kg. The substance is within the applicability domain (AD) of the estimation models according to Meylan et al. 1997/1999 (BCFBAF v3.01) and T.E.S.T. v4.1 (US EPA). If only considering these applicable models, the BCF estimations range from 10.0 to 33.7 L/kg. For the following models, the results of the applicability domain checks are not clearly defined (the substance could be out of the AD). The median of all calculated BCF values is 46.2 (24.9 if only clearly applicable models are considered). However, all calculations resulted in BCF values < 500 L/kg indicating no significant bioaccumulation potential of the substance.

Based on the available information on the log Kow (uncharged: log Kow = 2.73, estimated; log Kow = 2.82, measured) and a weight-of-evidence approach by the calculated data, it can be concluded that significant bioaccumulation in organisms is not to be expected.

Summary of relevant information on aquatic bioaccumulation: Predicted BCF values for applied QSAR models sorted by BCF (AD = Applicability Domain)

Model	BCF	In AD	Restraints
CAESAR v2.1.14(VEGA v1.1.1)	10.0	unclear	The result may not be reliable: - only moderately similar compounds in the training set - similar molecules with experimental values which disagree with predicted BCF value.
BCF Read-Across v1.1.0 (VEGA v1.1.1)	15.1	unclear	Substance could be out of the AD: - some similar molecules with experimental values which disagree with predicted BCF value - maximum error in prediction of similar molecules with moderate value
US EPA T.E.S.T. v4.1: Bioaccumulation: Consensus method	16.1	yes	-
Meylan v1.0.3 (VEGA v1.1.1)	29.0	unclear	Substance could be out of the AD: - only moderately similar compounds in the training set
BCFBAF v3.01 (EPI Suite v4.11): Meylan et al. (1997/1999)	33.7	yes	-
BCF baseline model v.02.08 (OASIS Catalogic v5.11.15): incl. mitigating factors	48.0	no	The substance is within the parametric and the mechanistic, but not within the structural domain due to unknown fragments (11.1%).
BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation	56.7	no	As the substance appreciably ionizes at physiologically relevant pH, the estimation may be less accurate.
BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation of zero	71.4	no	As the substance appreciably ionizes at physiologically relevant pH, the estimation may be less accurate.
BCF baseline model v.02.08 (OASIS Catalogic v5.11.15): not considering mitigating factors	136.0	no	The substance is within the parametric and the mechanistic, but not within the structural domain due to unknown fragments (11.1%).

 

 

QSAR-disclaimer

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met. Furthermore according to Article 25 of the same Regulation testing on vertebrate animals shall be undertaken only as a last resort.

According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

For the assessment of 2-ethylhexylamine (Q)SAR results were used for aquatic bioaccumulation. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.

Therefore, and for reasons of animal welfare, further experimental studies on aquatic bioaccumulation are not provided.