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The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Adsorption / desorption

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
adsorption / desorption, other
Remarks:
calculation of logKoc for ionized molecule
Type of information:
calculation (if not (Q)SAR)
Remarks:
estimated by calculation
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Scientifically acceptable calculation method
Principles of method if other than guideline:
Calculation method determining the Koc for charged molecules based on log Kow (uncharged molecule) and pKa.
Input parameters:
1. The substance is a base.
2. log Pow (for uncharged molecule) = -0.91
3. pKa = 9.95
GLP compliance:
no
Type of method:
other: calculation of pH corrected log Koc for ionized molecule
Media:
soil
Radiolabelling:
no
Remarks:
not relevant (Calculation)
Test temperature:
25 °C
Type:
Koc
Value:
21.3 L/kg
Temp.:
25 °C
Remarks on result:
other: pH 5 to 8
Type:
log Koc
Value:
1.33 dimensionless
Temp.:
25 °C
Remarks on result:
other: pH 5-8
Details on results (HPLC method):
not relevant for calculations

The data refer to the charged molecule.

Validity criteria fulfilled:
yes
Conclusions:
Methylaminoethanol is a base. At pH 5, 7 and 9, the same value of Koc value was obtained (Koc = 21 L/kg; logKoc = 1.33).
Executive summary:

Methylaminoethanol is a base. Therefore, Koc values can be calculated at different pH according to the calculation approach of Franco and Trapp. The Koc value was the same for the range of pH 5 - 9 (Koc = 21 L/kg; logKoc = 1.33). This indicates that surrounding pH will not have a great influence on adsorption coefficients of methylaminoethanol.

Description of key information

The key value for chemical safety assessment is estimated using the method of Franco &Trapp (2008).

Adsorption to solid phase of the N-Methylethanolamine (CAS 109 -83 -1) is not to be expected.

Key value for chemical safety assessment

Koc at 20 °C:
21

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 the N-Methylethanolamine (CAS 109 -83 -1) (Q)SAR results were used for the estimation of the adsorption potential. 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, further experimental studies on the adsorption potential are not provided.

 

Assessment

In order to assess the adsorption potential of the substance, the Koc value was estimated using QSAR models. According to the MCI method of the KOCWIN v2.00 module of EPI Suite v4.11, N-Methylethanolamine (CAS 109-83-1) has a Koc of 1.30. The MCI module is more reliable than the log Kow method of KOCWIN v2.00, which estimates the KOC based on the n-octanol/water partition coefficient (measured logKow: -0.91; uncharged molecule, BASF AG, BRU 89.018, 1989). The latter method resulted in a Koc of 0.92. These estimates are representative for uncharged molecules; the substance is within the applicability domain of the estimation models.

 

At environmentally relevant conditions, N-Methylethanolamine will be present in ionized form (pKa= 9.95 @ 20 °C, HSDB 2010, see IUCLID Ch 4.21). Therefore, the adsorption coefficient was calculated according to Franco & Trapp (2008, 2009, 2010) to correct for the charged molecule at pH 5, 7, and 8. This pH range is representative for 98 % of the European soils. The model is not yet validated; in addition, the applicability domain is not clearly defined. Nevertheless, the Koc values of the Franco & Trapp method give a good indication on the adsorption potential of a substance depending on the pH conditions of soil. The method is based on the dissociation constant pKa and the log Kow for the uncharged molecule.

The resulting Koc at pH 5-8 is 21 L/kg (log Koc: 1.33).

It can be concluded that adsorption to the solid soil phase is not expected under environmentally relevant conditions.

[LogKoc: 1.33]