1,4-dioxane

PBT assessment

PBT assessment: overall result

Reference

Reference 1

Name:

1,4-dioxane

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

1,4-dioxane

Reference 2

Name:

1,4-dioxane

Type of composition:

boundary composition of the substance

State / form:

liquid

Reference substance:

1,4-dioxane

PBT status:

the substance is not PBT / vPvB

Justification:

Parent compound:

The substance meets the criteria for classification as persistance (P) or very persistance (vP). As the substance is concluded to be not readily biodegradable (according to OECD criteria), it should be considered as potentially P/vP from a worst-case point of view.

However, the substance is not B/vB based on an experimental data available for the substance. (mean BCF = 0.45, OECD 305C, IUCLID Ch. 5.3.1).

The substance is also not T since the lowest available chronic value is >> 0.01 mg/L and the substance holds no relevant classification.

In conclusion, the substance is not to be considered as a PBT/vPvB substance.

PBT / vPvB – Assessment for modelled metabolites of 1,4-dioxane (CAS 123-91-1):

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 the main constituents of the substance 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).

CATALOGIC 301C v11.15 (OASIS Catalogic v5.13.1) predicted for the parent compound 8 metabolites, identifying no metabolites as relevant degradation products in terms of PBT/vPvB assessment, with an estimated quantity of ≥ 0.1% (for details see ‘Attached background material’ of the respective Endpoint Study Record).

Table 1. The predicted metabolites from the CATALOGIC 301C v11.15 estimation model.

The predicted metabolites for the substance from the CATALOGIC 301C v11.15 estimation

model

#	Smiles	Quantity [mol/mol parent]	log Kow	BOD (%)
Parent	C1COCCO1 (CAS 123-91-1)	0.991	-0.32	1
2	OC1COCCO1	8.987E-008	-1.86	99
3	OCCOCC=O	8.986E-008	-1.91	99
4	OCCOCC(O)=O	8.986E-008	-1.65	99
5	OC(=O)COCC=O	8.986E-008	-1.67	99
6	OC(=O)COCC(O)=O	8.98E-005	-2.01	99
7	OC(=O)C=O	1.779E-007	-1.4	100
11	OCC(O)=O	8.896E-008	-1.1	100
8	OC(=O)C(O)=O	1.779E-007	-1.7	100

(metabolite no: according to (Q)SAR model CATALOGIC 301C v11.15 – July 2018 (OASIS CATALOGIC v5.13.1.156))

In conclusion, there is no predicted metabolites present in a concentration of ≥ 0.1% (equivalent to >=0.001 mol/mol parent).