Carbamic acid ester

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 21 2014 to January 28 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study according to the guideline under GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.2120 (Hydrolysis of Parent and Degradates as a Function of pH at 25°C)

Principles of method if other than guideline:

An additional determination of hydrolysis at pH 2 was included in the protocol.
Only a preliminary test was performed.

GLP compliance:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid: viscous

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent products: at start and day 5
- Sampling method: in duplicate
- Sampling intervals/times for pH measurements: at start and day 5
- Sample storage conditions before analysis: analyzed immediately

Buffers:

Potassium chloride buffer pH 2:
solution of 4 ml potassium chloride solution (3 M) with 3 ml hydrochloric acid (1 M) with about 200 ml water to reach pH 2.
Acetate buffer pH 4, 0.01 M:
solution of 16.7% (v/v) 0.01 M sodium acetate in water and 83.3% (v/v) 0.01 M acetic acid in water. The buffer contains 0.0009% (w/v) sodium azide.
Phosphate buffer pH 7, 0.01 M:
solution of 0.01 M potassium di-hydrogenphosphate in water adjusted to pH 7 using 1 N sodium hydroxide. The buffer contains 0.0009% (w/v) sodium azide.
Borate buffer pH 9, 0.01 M :
solution of 0.01 M boric acid in water and 0.01 M potassium chloride in water adjusted to pH 9 using 1 N sodium hydroxide. The buffer contains 0.0009% (w/v) sodium azide

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: sterile vessel containing 6 mL test solution
- Sterilisation method: not indicated
- Lighting: in dark
- Measures to exclude oxygen: nitrogen gas purged through solution
- Is there any indication of the test material adsorbing to the walls of the test apparatus; no
- Test temperature: 49.8°C ± 0.2°C
TEST MEDIUM
- Volume used/treatment: 6 mL (1.00 mg/L)
- Kind and purity of water: milli-Q water
- Preparation of test medium: sterilised through a 0.2 um filter

Number of replicates:

2 replicates/ pH-value

Positive controls:

no

Negative controls:

not specified

Remarks:

blanks were included but not reported

Statistical methods:

NA

Results and discussion

Preliminary study:

Hydrolysis was < 10% at all pH values. The concomittant t1/2 is > 1 year at 25 °C

Test performance:

The slight deviation of the acceptable recovery range at pH 4 is not expected to have influenced the outcome of the test.
In view of the results of the preliminary study no further tests were performed

Transformation products:

not measured

Dissipation DT50 of parent compound

Remarks on result:

hydrolytically stable based on preliminary test

Any other information on results incl. tables

Preliminary hydrolysis test of the test substance at pH 2, pH 4, pH 7 and pH 9

pH code	Sampling time	Analysed concentration [mg/l]	Degree of hydrolysis [%]		Actual pH
			Individual	Mean
pH 2	0 hours	1.04			2.0
		1.05			2.0
	5 days	1.05	-0.44	-0.66	2.1
		1.06	-0.87		2.1
pH 4	0 hours	1.12			3.9
		1.10			4.0
	5 days	1.12	-6.6	-5.5	4.1
		1.09	-4.3		4.1
pH 7	0 hours	1.08			7.0
		1.08			7.0
	5 days	1.10	-2.3	-3.0	7.1
		1.12	-3.6		7.1
pH 9	0 hours	1.07			8.9
		1.11			8.9
	5 days	1.02	5.9	6.8	8.9
		1.00	7.7		8.9

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The hydrolysis rate of the substance at pH 2, 4, 7 and 9 is >1 year

Executive summary:

In a hydrolysis study performed according to OECD 111, the preliminary test at pH 2, 4, 7 and 9 showed hydrolysis < 10% at 50 °C over the 5 day test period..

It can therefore be concluded that the hydrolysis rate of the substance at all tested pH values is > 1 year.