[x Sodium, y Potassium, z Lithium, x+y+z =2] 4-amino-3-[[[(2,4-diaminophenyl)diazenyl]phenyl]diazenyl]-5-hydroxy-6-(phenyldiazenyl)naphthalene-2,7-disulfonate

Explosiveness

Link to relevant study record(s)

Reference

Endpoint:

explosive properties of explosives

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is an organic substance or mixture containing chemical groups associated with explosive properties, but the exothermic decomposition energy is less than 500 J/g and the onset of exothermic decomposition is below 500°C

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING

Expert statement

As stated in the reference (Comission Regulation (EC) N° 440/2008, Annex A.14, 1.1) "the tests need not to be performed when available thermodinamic information (e.g. heat of formation, heat of decomposition) and or absence of certain reactive groups in the structural formula establishes beyond reasonable doubt that the substance is incapable of rapid decomposition with evolution of gases or release of heat (i.e. the material does not present any risk of explosion)"

1.- According to the chemical structure and the list of reactive groups that could have explosive propeliies, as contiguous nitrogen atoms, in Bretherick's Handbook of Reactive Chemical Hazards, Butterworths, 4th Ed, it cannot be excluded that "Direct Black RBK" ([x Sodium, y Potassium, z Lithium, x+y+z =2] 4-amino-3-[[[(2,4-diaminophenyl)diazenyl]phenyl]diazenyl]-5-hydroxy-6-(phenyldiazenyl)naphthalene-2,7-disulfonate) could have explosive properties.

2.- The determination of the thermal stability of the test substance by DSC (Differential Scanning Calorimetry) showed that between 30°C and 400 °C the exothermal decomposition energy is about 879 kJ/kg. In spite of this value is higher than the limit of 500 kJ/kg needed for exclusion as given in Regulation (EC) n° 1272/2008 (CLP) of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, Chapter 2.1.4.3c., the fact that a direct flame applied on the substance (test of flammability A 10) was not able to ignite the dyestuff, and no other phenomena were observed on the substance in spite of the flame applied, everything as a whole corrobarates that it is not generated enough energy to make autocombustion by increasing the temperature, at least between room temperature and 400ºC.

3.- Final conclusion: It can be excluded that "Direct Black RBK" ([x Sodium, y Potassium, z Lithium, x+y+z =2] 4-amino-3-[[[(2,4-diaminophenyl)diazenyl]phenyl]diazenyl]-5-hydroxy-6-(phenyldiazenyl)naphthalene-2,7-disulfonate) has explosive properties.

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to other study

Key value for chemical safety assessment

Explosiveness:

non explosive

Justification for classification or non-classification

Based on the available information it can be excluded that the substance has to be classified as explosive, according to CLP Regulation.