Silybum marianum, 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:

18 March 2019 to 22 March 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

Commission Regulation (EC) No 440/2008 of 30 May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), Part A, A.6 Water Solubility

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

Organisation for Economic Co-operation and Development (OECD), OECD Guidelines for Testing of Chemicals, Guideline No. 105, "Water Solubility", adopted July 27, 1995

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

No further details specified in the study report

Key result

Water solubility:

< 0.1 vol%

Conc. based on:

test mat.

Temp.:

20 °C

Remarks on result:

other: pH, loading & incubation not specified

Details on results:

It should be noted that the Test Item is an UVCB substance. Therefore, the calculated value is only a theoretical concentration. This theoretical calculation assumes, that the carbon content of the pure Test Item and the carbon content of the dissoluble fraction are not different from each other, furthermore that all component has similar solubility in water.
The water soluble fraction of the test item depends on the actual amount of the test item (approximatelly 0.0032% of the test item can be soluble in water) therefore there is no well determined water solubility and the finding of a saturation plateau was not possible.

	Measured carbon content %
Nominal concentration (approx.)	100 mg/L	500 mg/L	2500 mg/L
Days
1	0.003203	0.002665	0.002598
2	0.001844	0.002519	0.002337
3	0.003556	0.002454	0.002527
Mean	0.002867664	0.002546146	0.002487334
	0.000903843	0.000108178	0.000135349
RSD%	31.518440048	4.248704989	5.441543995
	BQL

 

	Measured carbon content mg carbon/L
Nominal concentration (approx.)	100 mg/L	500 mg/L	2500 mg/L
Days
1	0.320275	1.332717	6.495681
2	0.184413	1.259300	5.841322
3	0.355611	1.227202	6.318000
Mean	0.286766394	1.273072912	6.218334584
	0.090384294	0.054089112	0.338373412
RSD%	31.518440048	4.248704989	5.441543995
	BQL

 

	Calculated soluble test item content %
Nominal concentration	100 mg/L	500 mg/L	2500 mg/L
Days
1	0.004118	0.003427	0.003341
2	0.002371	0.003239	0.003004
3	0.004573	0.003156	0.003250
Mean	0.003687365	0.003273943	0.003198320
	0.001162200	0.000139100	0.000174038
RSD%	31.518440048	4.248704989	5.441543995
	BQL

 

	Calculated soluble test item content mg/L
Nominal concentration (approx.)	100 mg/L	500 mg/L	2500 mg/L
Days
1	0.411824	1.713665	8.352426
2	0.237126	1.619262	7.511022
3	0.457260	1.577989	8.123956
Mean	0.368736523	1.636971727	7.995801188
	0.116220000	0.069550099	0.435095039
RSD%	31.518440048	4.248704989	5.441543995
	BQL

 

Conclusions:

The water soluble fraction of the test item depends on the actual amount of the test item (approximately 0.0032% of the test item can be soluble in water) therefore there is no well determined water solubility and the finding of a saturation plateau was not possible.

Executive summary:

The purpose of this study is to determine the organic carbon content of the water soluble fraction of Extract of Chardon marie without support, which is specified by the saturation mass concentration of the test item in water preferably at 20±0.5°C.

 

Although, as the expected water solubility is close to 10^-2g/L, the flask method will be applied due to technical reasons (relatively large volumes with repeat samples are required, only a flask mixture can provide this).

 

It should be noted that the Test Item is an UVCB substance. Therefore, the calculated value is only a theoretical concentration. This theoretical calculation assumes, that the carbon content of the pure Test Item and the carbon content of the dissoluble fraction are not different from each other, furthermore that all component has similar solubility in water.

The water soluble fraction of the test item depends on the actual amount of the test item (approximately 0.0032% of the test item can be soluble in water) therefore there is no well determined water solubility and the finding of a saturation plateau was not possible.

Description of key information

Water solublity <0.1%

Additional information

As the expected water solubility is close to 10^-2 g/L, the flask method will be applied due to technical reasons (relatively large volumes with repeat samples are required, only a flask mixture can provide this).

 

It should be noted that the Test Item is an UVCB substance. Therefore, the calculated value is only a theoretical concentration. This theoretical calculation assumes, that the carbon content of the pure Test Item and the carbon content of the dissoluble fraction are not different from each other, furthermore that all component has similar solubility in water.

The water soluble fraction of the test item depends on the actual amount of the test item (approximately 0.0032% of the test item can be soluble in water) therefore there is no well determined water solubility and the finding of a saturation plateau was not possible.