N1,N2-dimethyl-N1-{2-[methyl(propan-2-yl)amino]ethyl}-N2-(propan-2-yl)ethane-1,2-diamine

PBT assessment

PBT assessment: overall result

Reference

Type of composition:

boundary composition of the substance

State / form:

liquid

Reference substance:

PBT status:

the substance is not PBT / vPvB

Justification:

The criteria given in the “Guidance on information requirements and chemical safety assessment, chapter R.11: PBT Assessment” (ECHA, 2014c) are used as information to decide whether the target substance N2-dimethyl-N1-{2-[methyl(propan-2-yl)amino]ethyl}-N2-(propan-2-yl)ethane-1,2-diamine, and the source substance employed may potentially fulfil the PBT or vPvB criteria.

Persistence Assessment

Based on the available data, (N2-dimethyl-N1-{2-[methyl(propan-2-yl)amino]ethyl}-N2-(propan-2-yl)ethane-1,2-diamine is not readily biodegradable based on experimental data, as a mean degradation rate of 0% was observed after 28 days in a ready biodegradability assay. Thus, as no conclusion can be reached based on available information and in the absence of additional information to make a definitive determination, it may be presumed that the substance is potentially "persistent” (potentially “P”) and potentially very persistent (potentially “vP”).

Bioaccumulation Assessment

The bioaccumulation potential N2-dimethyl-N1-{2-[methyl(propan-2-yl)amino]ethyl}-N2-(propan-2-yl)ethane-1,2-diamineis expected to be low. This assumption is based on the following:

• The screening-level determinations that the substance is not bioaccumulative ("not B") and not very bioaccumulative ("not vB") are based on an experimentally determined log Kow of 0.27, which is substantially below the screening criterion (log Kow ≤ 4.5) for both “not B” and “not vB”.

Thus, screening-level, and definitive data indicate that the substance is “not bioaccumulative” (“not B”) and “not very bioaccumulative” (“not vB”).

Toxicity assessment

The determinations that the substance is “not CMR” and “not T, R48” or “Xn, R48” under the DSD/DPD classification, and are not carcinogenic (category 1A or 1B), germ cell mutagenic (category 1A or 1B), toxic for reproduction (category 1A, 1B or 2) or exhibit chronic toxicity (STOT-RE category 1 or 2) under the CLP Regulation, are definitive determinations of “not T” with respect to human health endpoints. The short-term screening-level data for aquatic toxicity determined EC50 (daphnids) = 65 mg/L > 0.1 mg/L). An acute toxicity study (OECD 203) limit test on the effects of (N2-dimethyl-N1-{2-[methyl(propan-2-yl)amino]ethyl}-N2-(propan-2-yl)ethane-1,2-diamine zebra fish (Danio rerio) was conducted. No fish died until the end of the exposure. Thus, the mortality in the control and in the test item as well treatment was 0%. No obvious effect on appearance and behavior of the fish in the test item treatment was observed. All test organism in the control as well as in the test item treatment appeared healthy and lively throughout the exposure. Thus, the LC50 (96h) is > 69 mg/L. In addition, a guideline study on the toxicity of the substance to a freshwater alga (Desmodesmus subspicatus) was conducted, and from which the 72 h ErC10 and 72 h ErC50 values were derived. EC 50 was 31.30 mg/L and EC10 18.72 mg/L. A guideline study on toxicity of the substance on Daphnia magna was conducted and the value EC50 (48 h) = 65.3 mg/L was derived.

All together the experimental data indicate that the substance is “presumably not T” with respect to aquatic toxicity.

Therefore, although a complete definitive determination cannot be made with respect to three endpoints (P, vP, and T), screening level criteria indicate that the substance is potentially “P”, potentially “vP”, “not B”, “not vB”, and “not T”. It is not necessary to have definitive criteria for all five endpoints to make the determinations as to whether the substance is “not PBT” and “not vPvB”. The determination based on screening criteria only requires that “each of the three properties persistency, bioaccumulation and toxicity need to be considered in conjunction” (Chapter R.11, “PBT Assessment”, Guidance on information requirements and chemical safety assessment, ECHA, May 2008, Section R.11.1.2.2, p. 13).The source substance 11 is already registered under Regulation (EC) No 1907/2006 and the PBT/vPvB Assessment as part of the Chemical Safety Assessment (CSA, Annex I) indicated that they are not PBT/vPvB¹.

[1] Information is based on the data publically available in the database on registered substances on ECHAs website.