Registration Dossier

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Ther substance is a blue-turquoise organic powder at 20 °C and 1013 hPa.The substance decomposed before melt/boil. Because of the physicochemical properties, vapour pressure and surface tension can be considered as negligible.

The substance is very water soluble (i.e. WS > 10 g/l)at 20 °C and is characterized by negative log Kow.

The substance does not ignite and propagate combustion. It does not meet the criteria to be considered as flammable/explosive/oxidising.

Additional information

Blue-turquoise organic powder. The substance decomposed 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).

 

APPEARANCE AND STATE

Direct Blue 199 is a blue-turquoise organic powder at 20 °C and 1013 hPa;it is characterized by a MMDA of 39.9 µm.

Thermal behaviour was investigated by the Differential Scanning Calorimetry (DSC): at the temperature of 230 °C an endothermic reaction was recorded, which was probably caused by the water evaporation. A second endothermic peak very low intensity was observed between 340 and 380 °C, caused by the thermal decomposition of the test substance. No further reactions have been recorded up to 500 °C. After the experiment the sample had lost of its mass and the residue had a black colour. Thus, the substance decomposed before melt/boil. Because of the physicochemical properties, vapour pressure and surface tension can be considered as negligible.

 

SOLUBILITY and PARTITION COEFFICIENT

Water solubility test was performed using the flask method. The concentration of the test substance in the aqueous solution was determined by the gravimetric method. Because concentrations in the two last vessels (2nd and 3rd day) do not differ by more than 15 %, the individual results from last two vessels could be averaged: 133.41 g/l (SD 2.51) at 20 °C and pH ca 4.8.

 

The partition coefficient was determined on Direct Blue 199_Na by shake flask method, according to the OECD guideline 107. The usage of information on Direct Blue 199_Na, which has the same main component and with a different counter ion, can be considered as suitable and appropriated because the difference in salification is expected to not influence the characteristics related to the specific end-point. The impurity profile does not impact on the read across proposed. Details on the approach followed are included in the document attached to the IUCLID section 13.

The concentration of the test substance in the water/octanol phases was determined spectrophotornetrically. Partition Coefficient between n-Octanol and aqueous phase was stated at 0.0051 at 25 °C and pH 4.2 (log Pow: -2.29). The experimentally determined log Kow value is outside the validity domain of the shake flask method according to OECD 107 (log Kow range: -2 to 4); furthermore, it is expected to be outside of the applicability domain of both the HPLC and the slow-stirring methods. Salts are generally characterized by a negative value of the log Kow, due to their hydrophilic character; thus, the experimental outcomes can be considered reliable and an evidence of the much greater affinity of the substance towards the water phase, compared to the affinity towards the octanol one.

 

PHYSICAL HAZARDS

Direct Blue 199 does not ignite and propagate combustion.

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

The flammability of Direct Blue 199_Na was examined in the burning behaviour test, according to the VDI-guideline 2263. The burning index was 2 (extinction occurs after short burning (no spreading of fire)), thus the test item can be considered as non-flammable. Furthermore, the specific investigation showed that no flammable decomposition gases were recorded up to 550 °C.

The explosive potential of the test substance was examined using available information on Direct Blue 199_Na: the falling hammer and in the powder explosiveness tests have been taken into account. No detonation was recorded in none of the replicates and the test substance resulted as not sensitive to impact. No reactions were recorded at none of the powder concentrations tested. The usage of information on Direct Blue 199_Na, which has the same main component and with a different counter ion, can be considered as suitable and appropriated because the difference in salification is expected to not influence the characteristics related to the specific end-point. The impurity profile does not impact on the read across proposed.

Furthermore, During the DSC analysis an endothermic peak was observed between 340 and 380 °C (7.67 J//g), caused by the thermal decomposition of the test substance and no further reaction has been recorded up to 600 °C.