Octanethioic acid, S-[3-(triethoxysilyl)propyl] ester, reaction products with 2-methyl-1,3-propanediol and 3-(triethoxysilyl)-1-propanethiol

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is highly insoluble in water

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

water solubility

Type of information:

other: Expert statement

Adequacy of study:

weight of evidence

Study period:

2022

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Qualifier:

no guideline followed

Principles of method if other than guideline:

The assessment was done based on general scientific principles.

GLP compliance:

no

Type of method:

other: theoretical assessment

Water solubility:

0.03 mg/L

Temp.:

20 °C

pH:

7

Conclusions:

Based on the water solubility values of analogous chemicals it is considered acceptable to use a water solubility value of 0.03 mg/L for risk assessment purposes for the registered substance.

Cross-reference 2

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-03-19 - 2008-05-13

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)

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

A preliminary test was performed at 50ºC ± 0.1ºC at each of pH 4.0, pH 7.0, and pH 9.1.The test item was dissolved in an aqueous solution at a specific pH-value and was incubated at a specific temperature to observe its hydrolysis behavior. The solutions were continuously stirred using a magnetic stirrer. The concentration of 2-methyl-1,3-propane diol, a hydrolysis product, was determined as a function of time at each pH.

GLP compliance:

no

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

- Sampling method: At each sampling point, a 3 ml aliquot of the test solutions at each pH value was transferred to a vial and subjected to GC analysis
- Sampling intervals/times for pH measurements: pH 4.0, pH 7.0, pH 9.1

Transformation products:

yes

No.:

#1

Key result

pH:

7

Temp.:

50 °C

Hydrolysis rate constant:

0 s-1

DT50:

8.2 h

pH:

9

Temp.:

50 °C

Hydrolysis rate constant:

0 s-1

DT50:

5.5 h

pH:

4

Temp.:

50 °C

Hydrolysis rate constant:

0 s-1

DT50:

4.8 h

Details on results:

The results of the individual measurements are summarized in the attached table.
The results of pH 4.0, pH 7.0, and pH 9.1 showed significant degradation of the test item at 50ºC. The degradation of the test item was higher than 50% after 14 hours at pH 7. Hydrolysis was faster at pH of 4 and 9.
According to the EEC Directive 92/69, Section C.7, it can be concluded that the estimated half-life time is shorter than one day under representative environmental conditions (25ºC). Therefore the registered substance was considered to be hydrolytically unstable.

Validity criteria fulfilled:

not specified

Conclusions:

NXT Z45 was found to be hydrolytically unstable.

Results and discussion

Transformation products:

not specified