Caryophyllene

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 April 2002 to 27 April 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

yes

Remarks:

Due to the test item properties it was impossible to load the test item to a carrier material as demanded by the guidelines. Therefore the study was conducted with the flask method regardless to the supposed water solubility of < 10 mg/L..

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

1992

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

0.088 mg/L

Conc. based on:

test mat.

Loading of aqueous phase:

225.25 mg/L

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

7

Details on results:

The measured concentration in at least two of the last test vessels did not differ by more than 15% (actual = 12.0%) and the temperatures were kept constant within ± 0.5°C; all validity criteria were met.

The analytical system gave linear response in the range of 0.097 - 0.582 mg/L. The precision of the method was tested using 5 replicates at rates of 0.097 and 0.582 mg/L. The coefficient of variation was 2.5% at 0.097 mg/L and 1.2% at 0.582 mg/L. The peak symmetry of the active ingredient was 1.0. Recovery was tested using a fortified sample at 0.097 mg/L. The coefficient of variation (n=5) was 7.5%. The limit of detection (LOD) was 0.047 mg/L and the limit of quantification (LOQ) was 0.070 mg/L.

Table 1. Solubility results

Sample	Test item concentration (mg/L)	Measured pH value
24 h	< LOQ	7.02
48 h	0.093	7.00
72 h	0.083	7.01
Mean (1)	0.088	-
Deviation (%)	12.0	-

(1) Mean value of the 48 and 72 h sample

LOQ = 0.070 mg test item/L

Conclusions:

The water solubility was determined to be 0.088 mg/L at 20°C and pH 7.0.

Executive summary:

The water solubility was tested according to OECD TG 105. This study is assigned a reliability of 1 (reliable without restrictions) as it followed an accepted guideline and was GLP-compliant. The water solubility was determined to be 0.088 mg/L at 20°C and pH 7.0.

Description of key information

The water solubility was determined to be 0.088 mg/L at 20°C and pH 7.0.

Key value for chemical safety assessment

Water solubility:

0.088 mg/L

at the temperature of:

20 °C

Additional information

Water solubility was tested using the flask method according to OECD TG 105. This study is assigned a reliability score of 1 as it followed an accepted guideline and was GLP-compliant. The water solubility of the test item was determined to be 0.088 mg/L at 20°C and pH 7.0.

A supporting study is available using a common approach for preparation of ecotoxicological test media of poorly soluble test items (2017). The maximum solubility was achieved after 96 hours with 0.094 mg/L in ultrapure water at room temperature, as determined by the slow-stirring experiment. This value is nearly identical and also comparable to the water solubility of 0.088 mg/L according to OECD 105.

This solubility determination study is assigned a reliability of 2 (reliable with restrictions) as it is not GLP-compliant and did not follow a guideline. However the experimental design and results are adequate and well-reported.