Cyclohexylidenebis[tert-butyl] peroxide

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019-07-23 to 2019-08-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

Slow-stirring conditions were applied. Test duration was 14 days.

GLP compliance:

no

Type of method:

flask method

Key result

Water solubility:

2.1 mg/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

10 mg/L

Incubation duration:

14 d

Temp.:

20 °C

pH:

ca. 7

Details on results:

The determined result for the water solubility of the test substance was an average value of two samples taken after 14 days. The average result was calculated to be 2.1 mg/L for the test substance.

Table 1: Results of test substance in water, no centrifugation

Time (days)	Concentration Replicate I (µg/L)	Concentration Replicate II (µg/L)	Average conc. (µg/L)
1	890.3	834	862.1
2	1345.7	1306	1325.8
3	1558.1	1585	1571.4
4	1739.7	1682	1711.0
7	1990.5	1936	1963.4
9	2125.1	2032	2078.6
11	2201.3	2159	2179.9
14	2160.3	2102	2131.0

 

Conclusions:

The water solubility of the test substance was determined to be 2.1 mg/L at 20 °C.

Executive summary:

The water solubility fo the test substance was determined in a study performed according to OECD 105 using the shake flask method. A slight modification ot the guideline was applied based on the physico-chemical properties of the test substance - slow-stirring was applied and the incubation period was extended to 14 days. The test was carried out in glass flasks with a Teflon tap near the bottom. The definitive test was performed at 10 mg/L, without centrifugation. It was determined that centrifugation resulted in substance loss due to adsorption to the test vessel walls. In duplicate flasks, approximately 10 mg of the test substance were weighed in and 1 litre of demineralised water was added to each flask. The flasks were placed in the dark at 20 °C and stirred as slowly as possible. At the time points 1, 2, 3, 4, 7, 9, 11 and 14 days after addition of the test substance, the solution was stopped and left to rest for 1 hour before samples were tapped. In duplicate about 10 mL was sampled from the bottom of the flask (dead volume of the tap was rinsed to waste) and transferred to separate centrifuge tubes. Subsequently, 2 mL hexane was added to the centrifuge tube to extract the test substance. The extracts were analysed with GC-MS. The determined result for the water solubility of the test substance was an average value of two samples taken after 14 days. The average result was calculated to be 2.1 mg/L at 20 °C.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2012-05-11 to 2012-05-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

adopted July 27, 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

31 May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Version / remarks:

March 1998

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Key result

Water solubility:

< 1 mg/L

Temp.:

20 °C

pH:

7.5

Key result

Water solubility:

< 1.07 mg/L

Temp.:

25 °C

Remarks on result:

other: Estimation of the water solubility using EUSES.

Details on results:

Preliminary test:
The water solubility of the test item was estimated to be ca. 6 mg/L in a preliminary test and therefore the column elution method was used in the main test.

Calibration:
The calibration solutions were prepared on each analytical occasion. The calibration samples were analysed by HPLC with three parallel injections from each. The 1,1-bis(tert-butylperoxy)cyclohexane concentrations were calculated with the help of the linear regression data.

Main test:
The water solubility of the test item was determined to be < 1 mg/L (Limit of Quantification, LOQ) at 20 °C ± 0.5 °C

Conclusions:

The water solubility of 1,1-bis(tert-butylperoxy)cyclohexane was estimated to be < 1 mg/L (quantification limit analytical method, HPLC-UV) at 20 °C ± 0.5 °C. Thus, the test item was considered to be slightly soluble or insoluble.

Executive summary:

The water solubility of 1,1-bis(tert-butylperoxy)cyclohexane was determined according to EU method A.6, OECD Guideline 105, and EPA OPPTS 830.7840 guideline. The water solubility of the test item determined to be < 1 mg/L (Limit of Quantification) at 20 °C ± 0.5 °C using the column elution method for the performance of the main test. Thus, 1,1-bis(tert-butylperoxy)cyclohexane was considered to be slightly soluble or insoluble.

Description of key information

The water solubility of the test substance was determined to be 2.1 mg/L at 20 °C.

Key value for chemical safety assessment

Water solubility:

2.1 mg/L

at the temperature of:

20 °C

Additional information

The water solubility fo the test substance was determined in a study performed according to OECD 105 using the shake flask method. A slight modification ot the guideline was applied based on the physico-chemical properties of the test substance - slow-stirring was applied and the incubation period was extended to 14 days. The test was carried out in glass flasks with a Teflon tap near the bottom. The definitive test was performed at 10 mg/L, without centrifugation. It was determined that centrifugation resulted in substance loss due to adsorption to the test vessel walls. In duplicate flasks, approximately 10 mg of the test substance were weighed in and 1 litre of demineralised water was added to each flask. The flasks were placed in the dark at 20 °C and stirred as slowly as possible. At the time points 1, 2, 3, 4, 7, 9, 11 and 14 days after addition of the test substance, the solution was stopped and left to rest for 1 hour before samples were tapped. In duplicate about 10 mL was sampled from the bottom of the flask (dead volume of the tap was rinsed to waste) and transferred to separate centrifuge tubes. Subsequently, 2 mL hexane was added to the centrifuge tube to extract the test substance. The extracts were analysed with GC-MS. The determined result for the water solubility of the test substance was an average value of two samples taken after 14 days. The average result was calculated to be 2.1 mg/L at 20 °C.

In a supporting study, the water solubility of 1,1-bis(tert-butylperoxy)cyclohexane was determined according to EU method A.6, OECD Guideline 105, and EPA OPPTS 830.7840 guideline. The water solubility of the test item was determined to be < 1 mg/L (Limit of Quantification, LOQ) at 20 °C ± 0.5 °C using the column elution method for the performance of the main test. Thus, the test item was considered to be slightly soluble or insoluble. The reason for the difference in the results can be the adsorption of the test item to the walls of the test vessels.