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Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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Description of key information

SIgnificant accumulation in organisms is not to be expected

Key value for chemical safety assessment

Additional information

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. Furthermoreaccording 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 2,2'-methyliminodiethanol (CAS 105-59-9) (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.

 

Assessment:

No experimental data on the bioaccumulation potential of 2,2'-methyliminodiethanol are available. In order to assess the bioaccumulation potential of the test substance, the BCF 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) for the compound. 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.

 

Summary of relevant information on aquatic bioaccumulation: Predicted BCF values for applied QSAR models sorted by BCF:

(AD = Applicability Domain)

Model

BCF [L/kg]

In AD

Restraints

Substance CAS 105-59-9

BCF KNN/Read-Across v1.1.0 (VEGA v1.1.3)

 

0.851

No

The maximum error in prediction of similar molecules found in the training set has a high value, considering the experimental variability

BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation

 

0.894

No

The substance appreciably ionizes at physiologically relevant pH

BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation of zero

 

0.896

No

The substance appreciably ionizes at physiologically relevant pH

 US EPA T.E.S.T. v4.2.1: Bioaccumulation: Consensus method

 

 0.9

Yes

Based on the mean absolute errors of the models compared to the training set data, the confidence in the predicted results is high.

 BCF baseline model v.02.09 (OASIS Catalogic v5.11.19): incl. mitigating factors

 2.34

 Yes

-

Meylanv1.0.3 (VEGA v1.1.3)

3

No

- reliability of log P value used by the model is not adequate

- LogP of this compound is outside the defined range [-1.37,11.26]

BCFBAF v3.01 (EPI Suite v4.11): Meylan et al. (1997/1999)

3.16

Yes

-

CAESAR v2.1.14 (VEGA v1.1.3)

3.16

Yes

The following relevant fragments have been found: Tertiary amine (SR05); OH group (PG 06) The tertiary amines fragment has been found in a number of non-bioaccumulative molecules even with high log Pow values. In addition, the OH group increases the hydrophilicity of a compound which is related to lower values of BCF.

BCF baseline model v.02.09 (OASIS Catalogic v5.11.19): not considering mitigating factors

9.29

Yes

-

 

Considering all models applied for 2,2'-methyliminodiethanol, the estimated BCF values range from 0.9 to 9.0 L/kg. Based on the available information on the log Kow (log Kow= -1.16; measured; BASF SE, 2011; report no. 10L00407) and supported by Weight of Evidence approach from calculated data it can be concluded that significant accumulation of 2,2'-methyliminodiethanol (105-59-9) in organisms is not to be expected.