Hexane-1,3,6-tricarbonitrile

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2022.3.10-2022.07.27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Buffers:

Citrate buffer pH 4 (50 mM):
23.02 g potassium dihydrogencitrate were dissolved in 1 L of water.
500 mL of this solution were mixed with 90 mL of 0.1 M sodium hydroxide and 410 mL of water.
The pH value of the buffer solution was determined to be 4.04.

Phosphate buffer pH 7 (50 mM):
13.61 g potassium dihydrogenphosphate were dissolved in 1 L of water.
500 mL of this solution were mixed with 296 mL of 0.1 M sodium hydroxide and 204 mL of water.
The pH value of the buffer solution was determined to be 7.00.

Borate buffer pH 9 (50 mM):
6.18 g boric acid were dissolved in 1 L of water.
500 mL of this solution were mixed with 213 mL of 0.1 M sodium hydroxide and 287 mL of water.
The pH value of the buffer solution was determined to be 9.04.

Details on test conditions:

General Information
Photolytic interference was avoided by shaking in the dark.
Buffer solutions were sterilized by ultra-filtration.
All used glass ware were sterilized with hot steam for half an hour.
Sterile water, ultra-pure grade was used.
The temperatures were kept and measured with a resolution of ± 0.2 °C.

Preliminary Test (Tier 1)
A preliminary test was performed at 50 ± 0.5 °C at three pH values 4, 7 and 9. Each sample was prepared in
triplicate and was measured twice for each pH value and at 50 °C in order to be able to estimate whether less
than 10 % of hydrolysis is observed after 120 hours or not.
Samples were taken at t0 and after 5 days (t5d) and prepared as described in chapter 3.7. The samples t0 were
analysed directly after preparation and subsequent dilution. The samples t5d were measured directly after
dilution.

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

>= 1.58 - <= 1.8 mg/L

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

>= 1.55 - <= 1.74 mg/L

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

>= 1.6 - <= 1.82 mg/L

Number of replicates:

3

Positive controls:

no

Negative controls:

no

Preliminary study:

The hydrolysis of the test item is negligible at pH 4, pH 7 and pH 9. The degradation of the test item was less than 10 % at pH 4, pH 7 and pH 9 at 50 °C over a period of 120 hours.

Transformation products:

no

pH:

9

Temp.:

50 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Remarks:

The degradation of the test item was less than 10 % over a period of 120 hours.

pH:

7

Temp.:

50 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Remarks:

The degradation of the test item was less than 10 % over a period of 120 hours.

pH:

4

Temp.:

50 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Remarks:

The degradation of the test item was less than 10 % over a period of 120 hours.

Validity criteria fulfilled:

yes

Conclusions:

The hydrolysis of the test item is negligible at pH 4, pH 7 and pH 9. The degradation of the test item was less than 10 % at pH 4, pH 7 and pH 9 at 50 °C over a period of 120 hours. Therefore, the corresponding half-life
time can be estimated to be longer than one year at 25 °C.

Executive summary:

Study Objective
The aim of this study was the determination of the abiotic degradation of Hexane-1,3,6-Tricarbonitrile as a
function of pH in aqueous solution. The test was performed according to OECD guideline 111.

Analytical Procedure
In brief, the test item was shaken in aqueous buffer for 5 days at three different pH-values at 50°C.

Result and Conclusion
The hydrolysis of the test item is negligible at pH 4, pH 7 and pH 9. The degradation of the test item was less
than 10 % at pH 4, pH 7 and pH 9 at 50 °C over a period of 120 hours. Therefore, the corresponding half-life
time can be estimated to be longer than one year at 25 °C.

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C