Reaction mass of N,N-ethanediylbis- Hexadecanamide, N-[2-[(1-oxohexadecyl)amino]ethyl]-Octadecanamide, Hexadecanoic acid, 12-hydroxystearic acid, reaction products with ethylenediamine, N,N-ethanediylbis-Octadecanamide and Octadecanoic acid, 12-hydroxystearic acid, reaction products with ethylenediamine

Endpoint summary

Description of key information

Hydrolysis

 

According to Column 2, Annex VIII of the EC 1907/2006, testing for this endpoint is not required if the substance is highly insoluble in water.The registered substance expected to be stable in water because the only chemical group in the structure of the three components that may be susceptible to hydrolysis is the amide, which is known to be stable at environmentally relevant pH and temperature. Furthermore, the low water solubility of the substance means that any hydrolysis occurring will be limited by the amount available in solution (SIDS, 2006).

 

Biodegradation

 

The ready biodegradation in the Modified MITI Test was determined with a non adapted inoculum for the test item over a period of 28 days. The study was conducted according to OECD guideline 301 C. The test item concentration selected as appropriate was 40 mg/L, corresponding to a ThOD of 108 mgO2/L in the test vessel. The oxygen was depleted by the respiration of bacteria and the degradation was followed by measuring the oxygen concentration. The biodegradation is therefore expressed as the percentage BOD and was calculated for each study day.

 

The oxygen depletion in the inoculum control came to 0.0 mgO2/L after 28 days.

 

In order to check the activity of the test system sodium benzoate was used as functional control. The functional control reached the pass level of a biodegradation > 40 % after 1 day and > 65 % biodegradation was reached after 3 days. After 17 days the degradation came to a maximum of 94 %.

The test item did not reach the 10 % level (beginning of biodegradation) until day 28. The biodegradation remained at a level of 0 – 4 %. The mean biodegradation came to 2 % after 28 days.

 

The test item must be regarded as not readily biodegradable in the 10-d-window and after 28 days.

 

Two additional studies investigating the ready biodegradability of the read Across Source substance Amides, C16-C18 (even), N,N'-ethylenebis were available. The report from Coenen (1991) was chosen as key study. This test was performed following the OECD Guideline No. 301B: Ready Biodegradability: Modified Sturm Test (1981), under GLP conditions. Activated sludge was used as inoculum and test material concentrations were 10 and 20 mg/L. On day 28 (end of the test) biodegradation values reached 15% and 5.5% at 10 and 20 mg/L test concentrations respectively. An additional supporting study was obtained from the Japanese Ministry of International Trade and Industry (MITI, 1976). This ready biodegradability test was carried out according to the OECD Guideline TG 301C: MITI (I), using activated sludge as inoculum at a concentration of 30 ppm. The test concentration used in the study was 100 ppm. After 14 days (end of the study), the test substance reached a biodegradation value of 1.1%. Thus, these results support those from the key study and Amides, C16-C18 (even), N,N'-ethylenebis can be considered as not readily biodegradable but the substance is hardly soluble in water and the very low solubility of the test substance may reduce the availability of the substance in the test medium.

Therefore, an additional calculation was used to investigate the biodegradation of  Amides, C16-C18 (even), N,N'-ethylenebis. A QSAR prediction using the following models Biowin1, Biowin2, Biowin3, Biowin4, Biowin5, Biowin6 and Biowin7 shows that the substance is not persistent in the environment and the biodegradation takes place in a time frame of weeks.

 

 

 

Bioaccumulation

 

The potential for bioconcentration of the Read Across substance Amides, C16-C18 (even), N,N'-ethylenebis in a freshwater fish, Cyprinus carpio, was investigated in one study from the Japanese Ministry of International Trade and Industry (MITI, 1988). The study was conducted according to OECD Guideline No. 305: Bioconcentration: Flow-through Fish Test (1996). The fishes were exposed to two concentrations of the test substance (0.830 mg/L and 0.083 mg/L) for a period of 6 weeks, under flow-through water conditions. At the end of the test, estimated BCFs were <0.7 and <6.2 at the 0.830 and 0.083 mg/L concentrations respectively. Therefore, the test substance did not exhibit potential for bioconcentration in fish species.       

 

Additional information about this endpoint could be gathered through BCF calculation using BCFBAF (v3.00), a subroutine of the EPI Suite™ computer program. The BCF estimated value, based on whole body wet weight, was 5.048, and thus it supports the experimental result.

 

In conclusion, there is no indication of bioaccumulation potential.

 

Adsorption/Desorption

 

Since the Constituent Amides, C16-C18 (even), N,N'-ethylenebis did not dissolve in (organic) solvents at sufficiently high levels, the adsorption coefficient could not be determined. Calculated log KOC (KOCWIN v2.00) values for the substance were 8.6 and 8.91. Thus, it has potential for adsorption to soil and sediment but this is a worst case approach for Amides, C16-C18 (even), N,N'-ethylenebis.