N,N-bis[3-(dimethylamino)propyl]-N',N'-dimethylpropane-1,3-diamine

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Screening-level data indicate that the substance (N,N-bis[3-(dimethylamino)propyl]-N',N'-dimethylpropan-1,3-diamine) is not readily biodegradable; a mean degradation rate of 2.4% was observed after 28 days in a ready biodegradability assay. In the absence of additional information to make a definitive determination, it may be presumed that the substance is “persistent” (presumably “P”) and potentially very persistent (potentially “vP”). 

 

Screening-level and definitive data indicate that the substance is “not bioaccumulative” (“not B”) and “not very bioaccumulative” (“not vB”). The screening-level determinations are based on an experimentally-determined log K_owof 0.05, which is substantially below the screening criterion (log K_ow≤4.5) for both “not B” and “not vB”. A definitive determination that the substance is “not B” and “not vB” is based upon the bioaccumulation study in carp, which indicated that bioconcentration is not of concern; the BCF value≤2 from the low concentration test and BCF≤ 0.7 from the high concentration testare each substantially below the definitive criteria for both “B” (> 2,000 L/kg) and “vB” (>5,000 L/kg). 

 

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) = 48 mg/L > 0.1 mg/L). An acute toxicity study (OECD 203) limit test on the effects of N,N-bis[3-(dimethylamino)propyl]-N',N'-dimethylpropane-1,3-diamine on 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 > 100 mg/L. The NOEC was reported to be >= 100 mg/L and the LOEC > 100 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 74.9 mg/L and EC10 5.1 mg/L. A guideline study on toxicity of the substance on Daphnia magna was conducted and the value EC50 (48 h) = 48 mg/L was derived. A semi-static reproduction test with Daphnia magna was conducted according to OECD 211 (02 October 2012, with TOC analysis to determine the test item exposure concentration) in order to investigate the chronic effects of the test item on daphnids. In the present study, five nominal concentrations of 0.33 – 27 mg/L test item were used. The EC10 was determined to be at 13.77 mg/L, based on the mortalities of the test item treatments

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.