Proxan-sodium

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Method details lacking. considered to be based on visual solubility without analysis.
Note that the substance is supplied in water at over 40% actives. When diluted, hydrolysis occurs.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Type of method:

flask method

Water solubility:

462 g/L

Temp.:

0 °C

pH:

10

Water solubility:

482 g/L

Temp.:

10 °C

pH:

10

Water solubility:

505 g/L

Temp.:

20 °C

pH:

10

Conclusions:

Although the solid will 'disappear' in water, the visual assessment does not differentiate between solution or hydrolysis.

Reference 2

Endpoint:

water solubility

Remarks:

Investigation into behaviour in water at different pH

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Justification for type of information:

The study was designed to establish behaviour in water.
Other data included as 'Weight of Evidence' demonstrate that up to 500 g/l will appear to dissolve, but it is unknown whether hydrolysis has a part in this.
This study involved assessing stability of solutions in water at gastric and environmental pH

Qualifier:

no guideline followed

Principles of method if other than guideline:

Study of the decomposition of eight samples of xanthates in simulated gastric fluid; sodium isoamyl xanthate, sodium isobutyl xanthate, sodium ethyl xanthateр potassium isoamyl xanthate, potassium ethyl xanthate (PEX). sodium isopropyl xanthate (SIPX), Potassium amyl xanthate and potassium isobutyl xanthate.

The reaction between simulated gastric fluid and the xanthate salts was carried out at 0 C for reasons of safety, as the reaction was expected to occur very quickly. The reaction mixture was then allowed to warm to room temperature over 1 hour, the final temperature being 25 C. A high degree of degradation at this temperature would lead to the inference that degradation would be at least as complete, if not more so, in actual gastric conditions.
Following the reaction solvent was added to produce a biphasic mixture, and the resulting organic phases were analysed by GC-MS to confirm the presence of the corresponding alcohols. These alcohols were quantified by comparison to known standards in order to confirm the completeness of the reaction, and to show that these salts behave in the same way under these reaction conditions.
It was not possible to detect carbon disulphide, considered to be due to rapid degradation in water to sulphur dioxide and carbon dioxide

GLP compliance:

no

Conc. based on:

test mat.

Loading of aqueous phase:

100 mg/L

Temp.:

0 °C

pH:

ca. 1.5

Remarks on result:

not determinable

Remarks:

Rapid hydrolysis. Not possible to detect parent material.

Conclusions:

Although public data and anecdotal evidence suggests a high level of solubility in water based on visual assessment when mixing in water in excess of 500 g/l, solubility assessment at concentrations relevant for biological and environmental exposure demonstrate rapid hydrolysis meaning that the parent compound was not possible to detect in water.
This study uses the same source data as the key Hydrolysis endpoint.

Description of key information

Although a high level of water solublity was observed under neutral / environmental pH, it is considered likely that when dissolved to biologically or environmentally relvent concentrations, the substance will be unstable. 

A study has been performed to assess behaviour in water at gastric pH to show rapid formation of hydrolysis products. 

Key value for chemical safety assessment

Water solubility:

505 g/L

at the temperature of:

20 °C

Additional information

The substance mixes well in water. but will hydrolyse.

Under acid conditions, there will be rapid hydrolysis.