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Physical & Chemical properties

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CAS 68971-49-3 is an organic yellow powder at 20 °C and 1013 hPa; it is a member of the Stilbene Fluorescent Whitening Agent (SFWA) category, group 3, dihydroxyethylamino derivative, hexasulphonated sodium salt

The substance has no melting point in the temperature range of 25 – 400 °C at atmospheric pressure (1013 hPa) it changes the colour (decomposes) starting from approximately 260 °C (capillary method).

Particle size distribution showed that the substance is characterized by a MMAD of 124 µm.

The partition-coefficient (n-octanol / water)has been determined by an appropriate in silico estimation method because Stilbene Fluorescent Whitening Agents are ionisable substances and therefor difficult to test. The partition coefficient value (experimentally measured) is expected to be outside the applicability range of the shake flask method, the HPLC method, and the slow-stirring method. Nevertheless, the estimated value can be considered an evidence of the much greater affinity of the substance towards the water phase, compared to the affinity towards the octanol phase.

It is very soluble in water (278 g/l at 20 °C), and fat solubility is lower than 0.1 mg/100 g fat.

Under environmental conditions the substance dissociates completely in water.

Since it is a solid, properties like vapour pressure, surface tension, flash point can be disregarded, while viscosity determination is technically not feasible.

It does not ignite and propagate combustion; no chemical groups associated with explosive and oxidising properties are present in the molecule.

It does not meet the criteria to be considered as flammable/explosive/oxidising.

Furthermore, screening test for thermal stability and stability in air, DTA, showed that no decomposition or chemical transformation were found below 150 °C, therefore it is not considered a self-reactive substance.