Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

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

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Adsorption of dimethyl(propyl)amine to the solid soil phase is possible. However, the substance is readily biodegradable

Key value for chemical safety assessment

Koc at 20 °C:
1 302

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.


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 dimethyl(propyl)amine (CAS 926-63-6) (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


According to Regulation (EC) No 1907/2006, Annex VIII, Section 9.3.1, Column 2, the study on adsorption/desorption screening does not need to be conducted if based on the physicochemical properties the substance can be expected to have a low potential for adsorption (e.g. the substance has a low octanol water partition coefficient), or the substance and its relevant degradation products decompose rapidly.


The substance is readily biodegradable according to OECD criteria (78% CO2 evolution after 28 d, BASF SE, 2012, report no. 27G0302/10G091; see IUCLID Ch. 5.2.1). In addition, the substance has a log Kow of 1.32 (BASF SE, 2013, measured at 23°C, pH=11; see IUCLID Ch. 4.7). Therefore, a study does not need to be conducted.


 


However, the Koc value was estimated using a calculation method according to Franco & Trapp (2008, 2009, 2010).


At environmentally relevant conditions, dimethyl(propyl)amine will be present in ionised form (pKa = 9.25; experimental database, 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 7 is 1302 (log Koc 3.11) (range pH 5 to 8: Koc = 1247 to 1308, log Koc = 3.1 to 3.12).


Under environmentally relevant conditions, adsorption to the solid soil phase is possible. The Koc value at pH 7 will be used as key value, i.e. for PEC and PNEC calculations.


 


The estimation of the Koc of the target substance is supported by calculations for the three structurally similar substances N,N-dimethylbutylamine (CAS 927-62-8), ethyldimethylamine (CAS 598-56-1) and triethylamine (CAS 121-44-8).


The table below lists the estimated Koc values for all substances. Detailed information on the model’s results are given in the endpoint study records of IUCLID Chapter 5.4.1.


 


Predicted Koc values from applied estimation method according to Franco&Trapp 2008/2009/2010








































SubstanceEstimation method

Koc



log Koc



Remarks



Target substance CAS 926-63-6



Franco&Trapp 2008/2009/2010



1302



3.1



pH 7, 25°C



Source substance


CAS 927-62-8


 



Franco&Trapp 2008/2009/2010



583



 2.8



pH 7, 25°C



Source substance


CAS 598-56-1


 



Franco&Trapp 2008/2009/2010



 135



 2.1



pH 7, 25°C



Source substance


CAS 121-44-8


 


 



Franco&Trapp 2008/2009/2010



411



 2.6



pH 7, 25°C



 


Based on the available calculated data for the target substance dimethyl(propyl)amine (CAS 926-63-6), it can be concluded that under environmentally relevant conditions adsorption to the solid soil phase is possible. However, the substance is readily biodegradable.


According to the read across data from the structurally similar substances N,N-dimethylbutylamine (CAS 927-62-8), ethyldimethylamine (CAS 598-56-1) and triethylamine (CAS 121-44-8), it can be concluded that adsorption to the solid soil phase is possible under environmentally relevant conditions.