Caesium nitrate

Endpoint summary

Additional information

Appearance:

Cesium nitrate is a odourless inorganic solid in colourless white crystalline form.

 

Melting point:

The determination of the melting point was performed according to EU Method A.1 and OECD Guideline 102 by applying the differential scanning calorimetry. The heat flow curves showed a small endothermic phase change between 150 and 152 °C, and upon further heating, a sharp endothermic peak with a peak maximum temperature at 404 °C and an extrapolated onset temperature of 401 °C. Therefore, the melting point of cesium nitrate was determined to be 401° C at 1013.25 hPa.

 

Boiling point:

In accordance with column 2 of the REACH Regulation (EC) No 1907/2006, Annex VII, section 7.3, the study does not need to be conducted for solids which either melt above 300 °C or decompose before boiling. The melting point of cesium nitrate was determined to be 401° C at 1013.25 hPa. Therefore, a study on boiling point is not required.

 

Density:

Using the gas displacement pycnometry method, the density of cesium nitrate was determined to be 3.64 g/cm³at 20 °C.

 

Particle size distribution:

The particle size distribution (volume distribution) of the test item was measured by laser diffraction according to ISO 13320 . The averages of three measurements were as follows: d10: 170 µm, d50: 258 µm, d90: 384 µm.

 

Vapour pressure:

In accordance with column 2 of the REACH Regulation (EC) No 1907/2006, Annex VII, section 7.5, the vapour pressure does not need to be conducted if the melting point is above 300 °C. The melting point of cesium nitrate was determined to be 401° C at 1013.25 hPa. Therefore, a study on vapour pressure is not required.

 

Partition coefficient:

In accordance with column 2 of the REACH Regulation (EC) No 1907/2006, Annex VII, section 7.8, the test on partition coefficient n-octanol/water does not need to be conducted if the substance is inorganic. Cesium nitrate is an inorganic compound. Therefore the estimated log Pow is expected to be =< 0 due to its salt character and good water solubility.

Water Solubility:

The determination of the water solubility of the test item was performed according to EU Method A.6 and OECD Guideline 105. The water solubility of cesium nitrate was determined to be 239.5 g/L at 20 °C using the shakeflask method for the performance of the main test. Therefore, the test item is very soluble.

 

Surface tension:

The determination of the surface tension of an aqueous solution of cesium nitrate was performed according to OECD Guideline 115 and EU Method A.5. The surface tension of the test item was determined in ten measurements. The measurements revealed values of 72.22 to 72.84 mN/m at 20 °C. The surface tension of cesium nitrate was determined as 72.5 mN/m at 20 °C.

 

Flash point:

As cesium nitrate is a solid at room temperature, the determination of the flash point is scientifically unjustified and therefore was not performed. Instead, a test on flammability for solids upon contact with air was conducted (see IUCLID Section 4.13).

 

Auto flammability:

Cesium nitrate was tested for Auto-ignition in a study according to EU method A.16. The ambient temperature showed nearly a straight line. Up to about 400 °C no exothermic reaction of the sample was observed. Consequently, the self-ignition temperature for the test item must be > 400 °C, if any at all.

 

Flammability:

Following EU Method A.10, the preliminary screening test did not indicate flammable properties. Because of the result of the preliminary test, cesium nitrate is considered non flammable.

 

Flammability in contact with water:

The chemical structure of cesium nitrate does not contain chemical groups, capable of causing the development of a dangerous amount of (flammable) gas (e.g. hydrogen), when in contact with damp air or water. In addition, from experience in handling and use no flammability in contact in water is expected. Therefore, the test substance is considered non flammable in contact with water.

 

Pyrophoric properties:

From the structural formula of cesium nitrate it can be concluded that the test substance is not pyrophoric. Cesium nitrate does not contain any chemical group that might lead to spontaneous ignition shortly after coming into contact with air at room temperature. In addition, from experience in handling and use no ignition in contact with air is expected.

 

Explosiveness:

As the sample was neither shock sensitive nor thermally or friction sensitive, according to the criteria of the EU Method A.14, cesium nitrate is not representing an explosive hazard and has not to be considered to present a danger of explosion.

 

Oxidizing properties:

Key-study:

A test on oxidizing properties of the sample cesium nitrate was performed according to the UN test method O.1. The lowest mean burning rate of 7.8 s was obtained with the mixture ratio sample to cellulose (4:1). This rate was less than the mean burning time of 12.6 s of a 3:2 mixture, by mass, of potassium bromate and cellulose of. Therefore the substance met the classification criteria of Division 5.1, PG I and was thus classified as oxidising.

Supporting study:

A test on oxidizing properties of cesium nitrate was performed according to the EU Method A.17. The highest burning rate of 4.76 mm/s was obtained with the mixture of 80 % test item : 20 % cellulose. This rate was obviously higher than the highest rate of the reference mixtures (3.63 mm/s). With regard to all test results the test item is assessed to have oxidizing properties.

 

Stability in organic solvents and identity of relevant degradation products:

In accordance with column 2 of the REACH Regulation (EC) No 1907/2006, Annex IX, section 7.15, the study which examines stability in organic solvents does not need to be conducted as the test substance cesium nitrate is an inorganic substance.

 

Dissociation constant:

The dissociation constant of cesium nitrate was determined according to OECD Guideline 112 with the titration method. The dissociation constant of cesium nitrate was not determinable because the test item is a strong electrolyte.

 

Viscosity:

The study which examines viscosity is not required according to the REACH Regulation (EC) No 1907/2006, Annex IX, section 7.17 as the test substance cesium nitrate is not a liquid.