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Environmental fate & pathways

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An assessment of hydrolytic stability was carried out using a procedure designed to be compatible with Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The results are as follows:

 

pH

Rate constant (h-1)

Estimated half-life at 25 °C (h)

4

6.63 x 10-2

10.4

7

6.72 x 10-2

10.3

9

6.68 x 10-2

10.4

 

TK 12146, ACCELERATOR DY 9577 was tested for its ready biodegradability in the Carbon Dioxide (CO2) Evolution test (Modified Sturm tst) at ca. 57 mg per 2 litres, corresponding to ca. 12 mg TC/l.

The relative degradation values calculated from the measurments performed during the test period revealed no significant degradation of TK 12146, in bottle A (SIGNIFICANT >10%), and 25% degradation in bottle B.

In the control toxicity TK 12146 was found to have no inhibiting effect on microbial activety.

Since all acceptability criteria prescribed by protocol were met, this study was considered to be valid.

In conclusion, TK 12146 was not readily biodegradable under the conditions of the modified Sturm test presently performed.

The inherent biodegradability of the test item was assessed in an aerobic aqueous medium. The test item attained 38%, 48% and 40% degradation with a mean of 42% degradation calculated from oxygen consumption values after 28 days. The test item can therefore be considered to show evidence for inherent, primary biodegradation under the terms and conditions of OECD Guideline No 302C.

No determination of the adsorption coefficient was possible by an HPLC estimation method compatible with Method C19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001. This was since the method was invalid for the test item.

No alternative estimation method was available for the determination of the adsorption coefficient of this test item. From experimental experience of studying quaternary amine containing compounds in soil/water systems using OECD Method 106, this cationic chemical class typically shows a very high affinity for soils.

Therefore in conclusion, from experimental experience, the test item was predicted to have a high affinity for soils.