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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. 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 DMAPA (CAS 109-55-7) (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 studies are available for the bioaccumulation assessment of the substance. According to Regulation (EC) 1907 (2006) Annex IX, Section 9.3.2, Column 2, a study on bioaccumulation does not need to be conducted as the substance has a low potential for bioaccumulation. The substance has an experimentally determined log Kow of -0.352 (at 25 °C; BASF AG 1988, report no.: 122968/02, see IUCLID Ch. 4.7). In addition, the log D for the dissociated form of the substance was estimated for the whole pH range (SPARC online calculator; BASF SE, 2020; see IUCLID Ch. 4.7). At pH 7 the log D was -3.03. At pH 9, the log D was -1.08. The log D values representing the charged substance are smaller than the log Kow of the uncharged molecule. Theses values are distinctly smaller than the critical values which would indicate a significant bioaccumulation potential (log Kow < 3). According to REACH Guidance R.7.1.8.5 (ECHA, 2017; R.7a v6.0), the value for the dissociated molecule determined around pH 7 (log D or log Dow) is considered more realistic for PBT and chemical safety assessment. It can be concluded that accumulation of the substance in organisms is not to be expected. Therefore, and for reasons of animal welfare, a study on bioaccumulation is not provided.

 

However, in order to assess the bioaccumulation potential of the 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). 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 (AD = Applicability Domain)

Model

BCF [L/kg]

In AD

Restraints

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

0.91

no

As the substance 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

0.94

no

As the substance ionizes at physiologically relevant pH, the estimation may be less accurate.

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

1.23

yes

Based on the mean absolute errors of the models the confidence in the predicted results is high.

KNN/Read-Across v1.1.0 (VEGA v1.1.5)

1.66

yes

-

BCF base-line model v03.10 (OASIS Catalogic v5.13.1.156): incl. mitigating factors

2.45

yes

-

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

3.2

yes

-

BCF baseline model v03.10 OASIS Catalogic v5.13.1.156): not considering mitigating factors

9.71

yes

-

 

The applied estimation models predicted for DMAPA (CAS 109-55-7) BCF values in a range between 0.91 L/kg (BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation, substance not in AD) and 9.71 L/kg (BCF baseline model v03.10 (OASIS Catalogic v5.13.1.156): not considering mitigating factors ; substance within AD).

According to the BCF base-line v03.10 model, metabolism is one of the mitigating factors for reducing the bioaccumulation potential of 3 -aminopropyldimethylamine (CAS 109 -55 -7). The relevant phase I reactions identified by the model are the following biotransformations: aliphatic N-oxidation, aliphatic C-hydroxylation and to a minor extent N-dealkylation.

Conclusion:

Based on the available measured data on the log Kow (log Kow = -0.35; BASF AG, 1988) and supported by a weight-of-evidence approach from calculated data, it can be concluded that significant accumulation in organisms is not to be expected.