2-[2-(dimethylamino)ethoxy]ethanol

PBT assessment

PBT assessment: overall result

Reference

Reference 1

Name:

2-[2-(dimethylamino)ethoxy]ethanol

Type of composition:

boundary composition of the substance

State / form:

liquid

Reference substance:

2-[2-(dimethylamino)ethoxy]ethanol

Reference 2

Name:

2-[2-(dimethylamino)ethoxy]ethanol

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

2-[2-(dimethylamino)ethoxy]ethanol

PBT status:

the substance is not PBT / vPvB

Justification:

PBT / vPvB – Assessment for modelled metabolites of DMEE (CAS 1704-62-7):

ECHA Guidance on information requirements and chemical safety assessment (v3.0, June 2017), Chapter R.11.4.1 specifies that “Constituents, impurities and additives should normally be considered relevant for the PBT/vPvB assessment when they are present in concentration of ≥ 0.1% (w/w)” […] “Similar arguments apply to relevant transformation/degradation products”.

In order to identify the relevant degradation products of DMEE as a standard information requirement according to Column 1, Section 9.2.3. of Annex IX to REACH and for purposes of an assessment of potential PBT/vPvB properties, the metabolites were modelled using CATALOGIC 301C v11.15 – July 2018 (OASIS CATALOGIC v5.13.1.156).

Overall, the model calculated 19 metabolites (Table 1) identifying 8 metabolites as relevant degradation products in terms of PBT/vPvB assessment, with an estimated quantity of ≥0.1% (equivalent to quantity setting in OASIS CATALOGIC: 0.001-2 [mol/mol parent]).

 

Table 1: QSAR prediction for CAS-#1704-62-7 (DMEE) using CATALOGIC 301C v11.15 – July 2018 (OASIS CATALOGIC v5.13.1.156;metabolites with a quantity > 0.001 mol/mol parent after 28 d are highlighted by grey background and bold type; metabolite no: according to (Q)SAR model Catalogic v11.15 – July 2018 (OASIS CATALOGIC v5.13.156))

#	Metab.	Smiles	Name and CAS no.	Quantity (mol/mol parent)	Log Kow	BOD (% after 28d, predicted)	PBT-Assessment: ECHA (disseminated substances)
Parent	1	CN(C)CCOCCO	2-[2-(Dimethylamino)ethoxy]ethanol (DMEE) (CAS no. 1704-62-7)	1.00E-05	-1.21	78	not PBT/vPvB
1	2	CN(C)CCOCC=O	2-[2-(Dimethylamino)ethoxy]acetaldehyde (CAS no. 1407486-83-2)	1.00E-05	-1.23	78	not found, not (pre-)registered
2	3	CN(C)CCOCC(O)=O	[2-(Dimethylamino)ethoxy] acetic acid (CAS no. 98278-28-5)	8.26E-02	-4.18	76	not found, not (pre-)registered
3	11	C=O	Formaldehyde (CAS no. 50-00-0)	1.28E-05	0.35	100	not PBT/vPvB
4	4	CN(C)CC=O	2-(Dimethylamino)acetaldehyde (CAS no. 52334-92-6)	7.63E-06	-0.96	81	not found, not (pre-)registered
5	16	OCC(O)=O	Glycollic acid (CAS no. 79-14-1)	9.02E-06	-1.07	100	not PBT/vPvB
6	17	CNCCOCC(O)=O	[2-(Methylamino)ethoxy] acetic acid (CAS no. 98137-58-7)	9.23E-03	-4.39	77	not found, not (pre-)registered
7	19	CN(CCOCC(O)=O)CO	{2-[(Hydroxymethyl)(methyl)amino]ethoxy} acetic acid (CAS no. -)	6.25E-03	-5.65	41	not found, not (pre-)registered
8	6	OC(=O)C=O	Glyoxylic acid (CAS no. 298-12-4)	1.71E-05	-1.40	100	not PBT/vPvB
9	12	OC=O	Formic acid (CAS no. 64-18-6)	1.28E-05	-0.46	100	not PBT/vPvB
10	5	CN(C)CC(O)=O	N,N-Dimethylglycine (CAS no. 1118-68-9)	4.85E-03	-2.73	79	not PBT/vPvB
11	18	CNCC=O	2-(Methylamino)acetaldehyde (CAS no. 145757-95-5)	8.31E-07	-1.17	83	not found, not (pre-)registered
12	20	CN(CC=O)CO	N-(2-Hydroxyethyl)-N-methylformamide (CAS no. 1590-50-7)	5.63E-07	-2.42	20	not registered
13	7	OC(=O)C(O)=O	Oxalic acid (CAS no. 144-62-7)	1.71E-05	-1.74	100	not PBT/vPvB
14	10	CNC	Dimethylamine (CAS no. 124-40-3)	5.33E-02	-0.17	71	not PBT/vPvB
15	15	CNCC(O)=O	Sarcosine (CAS no. 107-97-1)	3.68E-02	-2.94	81	registered, but no relevant data
16	21	CN(CC(O)=O)CO	N-(Hydroxymethyl)sarcosine (CAS no. 15826-50-3)	5.02E-02	-3.20	11	not registered
17	13	CN	Methylamine (CAS no. 74-89-5)	2.82E-01	-0.64	64	not PBT/vPvB
18	22	OCNCC(O)=O	Glycine, N-(hydroxymethyl)- (CAS no. 15874-34-7)	4.89E-04	-3.41	92	not found, not (pre-)registered
19	23	NCO	Methanol, amino- (CAS no. 3088-27-5)	5.65E-08	-2.10	100	not found, not (pre-)registered

Persistence (“P/vP”):

In order to assess the biodegradation potential of the relevant degradation products, the (Q)SAR model CATALOGIC 301C v11.15 – July 2018 (OASIS CATALOGIC v5.13.1.156) was applied.    

Concerning the applicability domain (OECD Principle 3) DMEE is in the parameter, the structural and the metabolic domain (100%).

- The model predicts a BOD value of 78% for DMEE, indicating that the chemical is readily biodegradable in contrast to the available experimental data. However, the model was used to predict potential metabolites.

- 2 of the 8 metabolites identified as relevant degradation products were calculated to be not readily biodegradable (threshold value: <60% BOD). Individual biodegradation of these metabolites was estimated to be in a range of 11% to 41% after 28 days (based on BOD).

- The majority of the relevant metabolites were estimated to be readily biodegradable (6 of 8; threshold value: ≥60%), with individually calculated biodegradation values between 60% and 100% after 28 days (based on BOD).

In conclusion, 75% of the predicted metabolites present in concentration of ≥0.1% (equivalent to quantity setting in OASIS CATALOGIC: 0.001-2 [mol/mol parent]) are estimated to be readily biodegradable while 25% of the relevant metabolites are predicted to be not readily biodegradable.

The two degradation products of DMEE (CAS-# 1704-62-7) which are predicted as not readily biodegradable metabolites should be considered as potentially P/vP from a precautionary point of view, until further data become available.

Bioaccumulation (“B/vB”):

Referring to uncharged molecules, the estimation model CATALOGIC 301C v11.15 – July 2018 (OASIS CATALOGIC v5.13.1.156) calculated for the parent compound DMEE (CAS-# 1704-62-7) a log Kow of -1.21, while in a test according to OECD 107 a log Kow of -0.78 at 20 °C was measured. Both values indicate low potential for bioaccumulation.

Without exception, all the 19 modelled degradation products of DMEE were estimated to exhibit log Kow values of clearly ≤4.5 (see Table 1), thereby not fulfilling the screening criteria for bioaccumulation (B/vB) as laid down in Section 3.1 of REACH Annex XIII.

Based on the estimation data available for the modelled metabolites, all relevant metabolites of DMEE are concluded to be “not B” and “not vB”.

Toxicity (“T”):

Considering potential “T” properties, limited data are available for the relevant metabolites of the parent compound DMEE. Only three of the relevant metabolites are registered under REACH. None of these substances were assessed to fulfill the criteria for “T”. Based on the available data on the persistence and bioaccumulation potential of all of the relevant metabolites, it can be concluded that all relevant degradation products do neither fulfill the PBT criteria (not PBT) nor the vPvB criteria (not vPvB).

Overall conclusion:

1.  Sufficient test data are available to assess the PBT/vPvB properties of DMEE.

2.  Potential relevant degradation products were modeled using (Q)SARmodel CATALOGIC 301C v11.15 – July 2018 (OASIS CATALOGIC v5.13.1.156):

2a. Based on modeled data relevant degradation products present in concentration of ≥ 0.1% (equivalent to quantity setting in OASIS CATALOGIC: 0.001-2 [mol/mol parent]) do neither fulfill the PBT criteria (not PBT) nor the vPvB criteria (not vPvB).

2b. However, two predicted relevant metabolites present in concentration of ≥0.1% (equivalent to quantity setting in OASIS CATALOGIC: 0.001-2 [mol/mol parent]) should be considered as potentially P/vP from a precautionary point of view.