E17-194T, (P,P-diethyl, monoester with 1,2 propanediol)_

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Januar - August 2020

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

17-194T, Lot #: 300567-78-7
Composition: P,P-diethyl, monoester with 1,2 propanediol - 92.9%, CAS #2230512-72-6
Physical Description: Clear, transparent liquid
pH: Neutral to slightly acidic
Stability: Test substance was expected to be stable for the duration of testing.
Expiration Date: aug 30, 2022

Radiolabelling:

no

Analytical monitoring:

yes

Buffers:

Composition was taken from the annex of the OECD method (buffer solutions 7 and 9) resp. Küster et al. (buffer solution 4). All chemicals used were of analytical grade. The pH was measured with a pH-meter with an uncertainty of 0.01 units and pH was adjusted to the nominal pH value ± 0.02 units.


Buffer-Solution, pH 4
CH3COOH, 2-m 16.0 mL
CH3COONa, 1-m 8 mL
Water ad 200 mL
Potassiumdihydrogenphosphate
KH2PO4, p.A.
Sodium hydroxide solution, 0.1-m
NaOH, p.A., 0.1 mol/L

Buffer-Solution, pH 7
KH2PO4 1.7418 g
Water 100 mL
NaOH, 0.1-m 59.5 mL
Water ad 200 mL
Boric acid
H3BO3, p.A.
Potassium chloride
KCl, p.A.

Buffer-Solution, pH 9
H3BO3 0.6184 g
KCl 0.7456 g
Water 100 mL
NaOH, 0.1-m 43 mL
Water ad 200 mL

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: PTFE filter, glass vials, Vials with PTFE septa. Incubation chambers Memmert and climate chamber OxiTop Box, wtw
- Sterilisation method: A solution of the test item in buffer solutions (pH values: 4; 7; and 9) was prepared and sterilised by sterile filtration.
- Lighting:Dark
- Measures taken to avoid photolytic effects: incubated in the dark under controlled laboratory conditions (at constant temperatures).
- Measures to exclude oxygen: no, buttThe sterile solutions were filled in sterilised vials and purged with argon (oxygen-free) be-fore the test.
- Details on test procedure for unstable compounds: no
- Details of traps for volatile, if any
- If no traps were used, is the test system: closed
- Is there any indication of the test material adsorbing to the walls of the test apparatus? no
TEST MEDIUM
- Volume used/treatment 100 ml
- Kind and purity of water: Deionised water
- Preparation of test medium: a solution of the test item was prepared by dissolving 50 mg test item in 100 mL of hydroly-sis buffer /demineralised water 50/50 % (v/v) and subsequent sterile filtration with 0.2 µm PTFE filters (resulting concentration of these sterile solutions: 500 mg/L).
- Renewal of test solution: no
- Identity and concentration of co-solvent: no
OTHER TEST CONDITIONS
- Adjustment of pH: no
- Dissolved oxygen:no

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

451 mg/L

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

459 mg/L

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

497 mg/L

Number of replicates:

6 replicate for each pH

Positive controls:

no

Negative controls:

no

Preliminary study:

Only preliminary study was performed as no degradation observed after 5 days at 50 degree. The results above are for the preliminary study

Test performance:

see above

Transformation products:

no

Key result

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Key result

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Key result

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Details on results:

A solution of the test item in buffer solutions (pH values: 4; 7; and 9) was prepared and sterilised by sterile filtration. The resulting solutions were stored at 50 °C oxygen-free in the dark for a period of five days. Samples were taken at the beginning and after five days. The analysis of the samples (performed with HPLC) did not show significant changes ≥ 10% in the concentration of the test item within five days.

pH % of start concentration after 5 days % decrease within 5 days
4 91.6 8.4
7 94.5 5.5
9 93.0 7.0

Validity criteria fulfilled:

yes

Conclusions:

A solution of the test item in buffer solutions (pH values: 4; 7; and 9) was prepared and sterilised by sterile filtration. The resulting solutions were stored at 50 °C oxygen-free in the dark for a period of five days. The substance does not hydrolize under teir 1 test conditions.Hydrolysis is less than 10%, thus, t1/2 is greater than 1 year at 25 degree.

Executive summary:

A solution of the test item in buffer solutions (pH values: 4; 7; and 9) was prepared and sterilised by sterile filtration. The resulting solutions were stored at 50 °C oxygen-free in the dark for a period of five days. The substance does not hydrolize under  teir 1 test conditions.Hydrolysis is less than 10%, thus, t1/2 is greater than 1 year at 25 degree.

Description of key information

The substance did not hydrolized under teir 1 test conditions

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C