Fatty acids, lanolin, esters with cholesterol-low lanolin alcs.

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 December 2017 to 06 March 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

non GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Principles of method if other than guideline:

a preliminary test was performed

GLP compliance:

no

Remarks:

Quality of the report is similar to that of a report under GLP conditions

Specific details on test material used for the study:

The substance was disolved in dichloromethane

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Samples were transferred to a measuring cylinder to accurately record the volume of each aliquot and then to a separating funnel.
The sample bottle was rinsed with an aliquot of dicholromethane (DCM) and this rinse added to the separating funnel. 50 ml of DCM was then added to each sample and the funnels transferred to a mechanical shaker for 5 minutes. The sample was allowed to settle and the DCM decanted into conical flasks containing sodium sulphate, then drawn off and transferred to a sodium sulphate drying column. The resulting extract was then concentrated to 1 ml and put into vials ready for analysis and stored in the fridge (3.6ºC).

At pH 9 some undissolved particles were present

Buffers:

- pH: 4
- Composition of buffer: 4ml of 0.1M NaOH + 500ml of 0.1M Potassium phthalate monobasic
- pH: 7
- Composition of buffer: 296.3ml of 0.1M NaOH + 500ml of 0.1M monopotassium phosphate
- pH: 9

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks: amber bottles with 500mL buffer solution
- Sterilisation method: The buffers are sterilised by filtering to 0.2μm, test was not conducted under sterile conditions
- Measures to exclude oxygen: removed from the bottles by passing nitrogen into the head space prior to sealing
TEST MEDIUM
- Volume used/treatment: 500 mL
- Kind and purity of water: deionised water
- Identity and concentration of co-solvent: dichloromethane (<1% v/v)

0.1012g of the substance was weighed directly into a 100ml volumetric flask and made to volume with DCM to give a sample stock concentration of 10.12 mg/l (pH=7.00). 230µl of sample stock was pipetted into amber bottles containing the different buffer solutions (500ml). A spike was also prepared in 500ml of deionised water.

Duration:

5 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

233 mg/L

Remarks:

concentration prepared

Duration:

5 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

233 mg/L

Remarks:

concentration prepared

Duration:

5 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

233 mg/L

Remarks:

concentration prepared

Number of replicates:

not indicated

Negative controls:

yes

Remarks:

deionised water

Statistical methods:

NA

Preliminary study:

Only a pre-test was performed. The substance is not hydrolitically stable at pH 4, 7 and 9 (see tables)

Transformation products:

not measured

pH:

4

Temp.:

50 °C

DT50:

< 5 d

Remarks on result:

other: hydrolytically instable based on preliminary test

pH:

7

Temp.:

50 °C

DT50:

< 5 d

Remarks on result:

other: hydrolytically instable based on preliminary test

pH:

9

Temp.:

50 °C

DT50:

< 5 d

Remarks on result:

other: hydrolytically instable based on preliminary test

2.4 Hours	Retention time (mins)	Peak area (%)	Conc (mg/l)	% Recovery
pH4	13	1919	41.239	17.699
pH7	13.00	5110	114.983	49.349
pH9	13.00	1963	42.256	18.136
Spike 13.00	9872	225.033	96.581

 

5 Days	Retention time (mins)	Peak area (%)	Conc (mg/l)	% Recovery
pH4	13	335	4.633	1.988
pH7	13.00	1284	26.564	11.401
pH9	13.00	1251	25.802	11.074

 

Concentration and Hydrolysis

	Sample Loading mass (g)	pH	% Recovery after 5 days	Total reaction of substance (%)
A	0.1001	4	1.988	98.012
B	0.1001	7	11.401	88.599
C	0.1001	9	11.074	88.926

 

Conclusions:

The substance hydrolyses >10% within 5 days at pH, 4, 7 and 9

Executive summary:

In a preliminary test performed according OECD 111, recoveries of  the of the substance solution was low for pH 4 (1.988% of initial), pH 7 (11.401% of initial) and pH 9 (11.401%of initial). Due to the low recoveries it  can be asserted that  hydrolysis occurred within all of the pH environments and this was rapid (< 50% recovery at 2.4 hours in all pH environments).

As >10% of the substance has been hydrolysed after 5 days, it is considered hydro-statically unstable under the conditions of this test.

Description of key information

In a preliminary test performed according OECD 111, recoveries of the analogue substance solution was low for pH 4 (1.988% of initial), pH 7(11.401% of initial ) and pH 9 (11.401% of initial ). Due to the low recoveries it  can be asserted that  hydrolysis occurred within all of the pH environments and this was rapid (< 50% recovery at 2.4 hours in all pH environments).

As >10% of the substance had been hydrolysed after 5 days, it is considered hydro-statically unstable under the conditions of this test.

Key value for chemical safety assessment

Half-life for hydrolysis:

5 d

at the temperature of:

50 °C

Additional information

A hydrolysis test (OECD 111) with Fatty acids, C10-30, esters with lanolin alcs. is available, but no tests on Fatty acids, lanolin, esters with cholesterol-low lanolin alcs. are available. The outcome of the hydrolysis test for Fatty acids, C10-30, esters with lanolin alcs. will be used in a read-across for the structurally very similar Fatty acids, lanolin, esters with cholesterol-low lanolin alcs.