Juniper, Juniperus oxycedrus, ext.

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 04 to 10, 2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an internationally recognised method, and under GLP. The substance is considered to be adequately characterised with its purity. Considering the complex nature of the substance, the quantification of the substance in water was performed using a non specific method. The values obtained should be considered with caution for the purpose of CSA.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected on 13 and 14 October 2014 / signed on 08 April 2015

Type of method:

flask method

Key result

Water solubility:

>= 80.8 - <= 232.2 mg/L

Temp.:

20 °C

pH:

>= 4.58 - <= 4.83

Remarks on result:

other: solubility range for the tested nominal concentration range 303 – 1003 mg/L

All measurements on day 3 (flasks 1A-C and 2 - 6) were included in the calculation of the solubility of the test item in water.

 

Table 4.8/7: Measurements used for Calculation of Solubility

 

Flask	Measured concentration of test item (mg/l)	Nominal concentration of test item (mg/l)	Dissolved Part [%]	pH value
2	36.2	103	35.1**	5.26
3	80.8	303	26.7	4.83
1*	124.9	501	24.9	***
4	147.5	601	24.5	4.74
5	190.5	804	23.7	4.59
6	232.2	1003	23.1	4.58

  * mean value of flasks 1A-C

** value was stated as outlier (Grubbs outlier test)

*** was not measured using pH meter

 

As solubility was dependent on nominal concentration, no exact value for the solubility of the test item in water can be stated. The solubility range for the tested nominal concentration 303 – 1003 mg/L is 80.8 – 232.2 mg/L at 20.0 ± 0.5 °C (80.8 – 232.2 * 10^-3 kg/m³ in SI units), corresponding to 24.6 % of the test item (mean value) relating to the nominal concentration of the test item.

 

DISCUSSION

The solubility of the test item in water was determined from the measured concentrations of DOC in the filtrated test solutions.

Equilibrium was considered as reached after 3 days.

Dependency of solubility on amount of the test item (nominal load) was perceived in the study. Therefore, no exact value for the solubility of the test item in water can be stated.

The solubility range for the tested nominal concentration 303 – 1003 mg/L is 80.8 –232.2 mg/L at 20.0 ± 0.5 °C, corresponding to 24.6 % of the test item (mean value) relating to the nominal concentration of the test item. The value for the nominal load 103 mg/L was stated as outlier.

Dependency of pH value on amount of the test item (nominal load) was perceived, too. The higher the nominal load of the test item, the lower is the pH value.

No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Conclusions:

Considering a water solubility of the test item between 80.8 and 232.2 g/L at a loading rate of 303 - 1003 mg/L at 20.0 ± 0.5 °C (pH 4.58 - 5.26; 3 days of equilibrium), the substance is considered as slightly to moderately soluble in water.

Executive summary:

The water solubility of the test item was determined under GLP according to OECD 105 Guideline and EU Method A.6 using the flask method.

The concentration of the test item dissolved in water was determined by measurement of DOC concentration (dissolved organic carbon) in the filtrated test solutions using TOC analyser.

Using a loading rate of 501mg/L, no significant difference between the concentrations of test item obtained at 20.5 ± 0.5 °C after 1, 2 or 3 days of equilibration was observed. Therefore, the equilibrium was considered as reached after 3 days at this loading rate.

Dependency of the solubility of the substance and the pH on the loading rate (nominal concentration) were perceived in the study. Therefore, no exact value for the solubility of the test item in water can be stated.

The solubility for the tested nominal concentration range 303-1003 mg/L was stated as a range between 80.8 and 232.2 mg/L at 20.0 ± 0.5 °C and pH 4.58 - 5.26 after 3 days of equilibrium. These values are estimated to correspond at about 24.6 % of the test item (mean value) dissolved in water relating to the nominal concentration of the test item.

Description of key information

The water solubility of the test item was measured between 80.8 and 232.2 g/L using a loading rate of 303 - 1003 mg/L at 20.0 ± 0.5 °C (pH 4.58 - 5.26; 3 days of equilibrium).

The substance is considered as slightly to moderately soluble in water pending on the lodaing rate.

Additional information

A reliable experimental study, conducted according to a recognized OECD/EC method (flask method) and under GLP is available. Despite restrictions due to the complex nature of the substance and the non specific method used to quantify the substance in water, the study is considered as a key study but the values obtained should be considered with caution for the purpose of CSA.