Sodium cyanate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2008-12-02 to 2009-06-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other study

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

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

96.4 g/L

Temp.:

20 °C

pH:

ca. 10

Details on results:

The measured values show good correspondence. No plateau could be reached due to the hydrolytical properties of the test item in the first experiment: Cyanates decompose in aqueous solutions forming ammonia and carbonate. This process started after the sampling of day three of the first experiment, making it impossible to generate solubility values with sufficiently small differences. Therefore the results of the second experiment are considered to be adequate for the determination of the solubility.
The water solubility of sodium cyanate is stated as 96.4 ± 4.0 g/L at 20 ± 0.5 °C.
No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Conclusions:

Interpretation of results: very soluble (> 10000 mg/L)
The water solubility of sodium cyanate is stated as 96.4 ± 4.0 g/L at 20 ± 0.5 °C.

Executive summary:

In a preliminary study, the solubility of the test item sodium cyanate in water was estimated as approx. 100 g/L.

In a first experiment, 500 g/L were weighed into each of six individual vessels, water was added, and the vessels were shaken on an orbital shaker for three days (over the week-end). Then, samples were taken on five consecutive days. A strong decreasing tendency was observed (from 90 g/L to 47 g/L). It was assumed that the test item undergoes hy-drolysis after a longer time period. This behaviour of cyanates is also reported in the literature. Therefore, a second experiment was performed.

In the second experiment, again 500 g/L were weighed. Samples were taken after 2, 4, 7.5, 24 and 30 hours. The highest measured value for the solubility of the test item was 102.7 g/L after 7.5 hours. Mean ± standard deviation of the 5 samples was 96.4 ± 4.0 g/L, giving a relative standard variation of 4.2%. This relative plateau is used for the calculation of the water solubility of sodium cyanate.

Water solubility of sodium cyanate is stated as: 96.4 ± 4.0 g/L at 20 ± 0.5 °C.

Description of key information

Water solubility of sodium cyanate is stated as: 96.4 ± 4.0 g/L at 20 ± 0.5 °C.

Key value for chemical safety assessment

Water solubility:

96 400 mg/L

at the temperature of:

20 °C

Additional information

In a preliminary study, the solubility of the test item sodium cyanate in water was estimated as approx. 100 g/L.

In a first experiment, 500 g/L were weighed into each of six individual vessels, water was added, and the vessels were shaken on an orbital shaker for three days (over the weekend). Then, samples were taken on five consecutive days. A strong decreasing tendency was observed (from 90 g/L to 47 g/L). It was assumed that the test item undergoes hydrolysis after a longer time period. This behaviour of cyanates is also reported in the literature. Therefore, a second experiment was performed.

In the second experiment, again 500 g/L were weighed. Samples were taken after 2, 4, 7.5, 24 and 30 hours. The highest measured value for the solubility of the test item was 102.7 g/L after 7.5 hours. Mean ± standard deviation of the 5 samples was 96.4 ± 4.0 g/L, giving a relative standard variation of 4.2%. This relative plateau is used for the calculation of the water solubility of sodium cyanate.

Water solubility of sodium cyanate is stated as: 96.4 ± 4.0 g/L at 20 ± 0.5 °C.