Hexasodium 2,2'-[vinylenebis[(3-sulphonato-4,1-phenylene)imino[6-[(2-cyanoethyl)[2-(2-hydroxyethoxy)ethyl]amino]-1,3,5-triazine-4,2-diyl]imino]]bis[benzene-1,4-disulphonate]

Endpoint summary

Description of key information

Yellow organic powder. The substance decomposes before melt/boil; it is very water soluble and has a negative log Kow.

Based on the available information, it is not characterized by physical hazard(s).

Additional information

APPEARANCE AND STATE

Optical Brightener 380 is a yellow organic powder at 20 °C and 1013 hPa; it is marketed and used in non solid, non granular form

The thermal behaviour of the substance was investigated using the Differential Scanning Calorimetry method and results were confirmed by the capillary method. The test item showed abroad endothermic effect starting at a temperature of approx. 55 °C, a second broad endothermic effect starting at a temperature of approx. 280 °C and a third broad endothermic effect starting at a temperature of approx. 429 °C; no further endothermic or exothermic effect was observed up to a temperature of 500 °C. Therefore, the test item decomposes before melt/boil, starting at a temperature of approx. 280 °C.

Based on the thermal behavious, the vapour pressure can be estimated as negligible.

The substance is characterized by a relative density of 1.622 at 20 °C.

SOLUBILITY and PARTITION COEFFICIENT

The water solubility was determined by flask method and the substance was measured using a validated analytical HPLC-UV method. The water solubility was determined to be 1006.4 g/l (RSD = 7.09 %) at 20 °C and pH 7.71 – 7.78. To verify the accuracy of the analytical method a fresh prepared standard solution (prepared with the test item) was measured in between the samples of the flask method. The recovery rate of the measured standard solutions was in the range from 96.1 to 102.3 %, which shows a good accuracy of the analytical method.

Due to the high affinity with the water phase respect to the octanol one, the log Pow was estimated from the individual solubilities in water and 1-octanol. The solubility of the test item in 1-octanol resulted to be less than the Limit of Quantification (LOQ), i.e. less than 168.84 mg/l. On the contrary, as abovementioned, the substance water solubility of the test item was determined to be 1006.4 g/l at 20 °C. Therefore, the estimated Pow from the individual solubilities resulted to be lower than 1.68 x 10^-4, corresponding to a log Pow lower than -3.78.

PHYSICAL HAZARDS

The self-ignition behavior of the Optical Brightener 380 was determined in the Grewer Oven test, according to VDI 2263, sheet 1. On the basis of the results of the screening test, the substance resulted to be not a self-heating substance, according to UN Transport Regulation.

The flammability potential of test item was investigated by preliminary test, in accordance with the method and procedures outlined into the Recommendations on the Transport of Dangerous Goods (Readily Combustible Solids, Test N.1). Under the experimental conditions, the substance did not ignite at room temperature using a flame as ignition source being applied for at least 2 minutes. Therefore, it has not to be classified as readily combustible solid in class 4.1 according to the UN Transport Regulation.

Regarding the explosiveness, screening procedure failed to evidence any reason for concern on the basis of the substance thermal behaviour. In addition, on the basis of its chemical structure, the substance is incapable of reacting exothermically with combustible materials.

Therefore, no physical hazard(s) was identified.