Disodium 8-[[4-[[(4-methylphenyl)sulphonyl]oxy]phenyl]azo]-5-[[4-[(4-nitro-2-sulphonatophenyl)amino]phenyl]azo]naphthalene-1-sulphonate

Endpoint summary

Additional information

The substance is a red brown powder with a characteristic odour.

In a DSC analysis showed decomposition beginning at 273 °C.

Relative density was determined by means of a pycnometer OECD 109 and the result value was D at 20 °C: 1.5915.

Granulometry is of considerable importance for the toxic properties of a substance as it influences aspects such as: the route of exposure of humans and toxicity by inhalation; the choice of route of administration for animal testing; the efficiency of uptake in an organism; the distribution in the environment.

The substance presented a granulometry mass median aerodynamic diameter (MMAD)= 676.6 µm. This granulometry can be considered as inhalable fractions (CEN document, EN 481‘Workplace Atmospheres - size fraction definitions for measurement of airborne particles”, 1993).

0% in volume of the test item has a particle size <= 4 µm (respirable fraction (the mass fraction of particles that reaches the alveoli).

The CEN document, EN 481 ‘Workplace Atmospheres – size fraction definitions for measurement of airborne particles’ (CEN 1993) provides definitions of the inhalable, thoracic and respirable size fractions, and target specifications (conventions) for sampling instruments to measure these fractions. The current standard defines sampling conventions for particle size fractions which are to be used in assessing the possible health effects resulting from inhalation of airborne particles in the workplace. The different particle sizes defined in EN 481 are: - inhalable fraction (the mass fraction of particles that can be inhaled by nose and mouth. Particles >100 μm are not included in the inhalable convention; - thoracic fraction (the mass fraction of the inhaled particles that passes the larynx). The convention for thoracic fraction sets that 50% of the particles in air with an aerodynamic diameter of 10 μm belong to the thoracic fraction; - respirable fraction (the mass fraction of the inhaled particles that reaches the alveoli). The convention for respirable fraction sets that 50% of particles with an aerodynamic diameter of 4 μm belong to the respirable fraction.)

According to Annex VII of REACH Regulation1907/2006, column 2, the study of vapour pressure does not need to be conducted for this substance but the lowest value accepted by EUSES has been reported for a complete Risk assessment (0.0000001 Pa).

Partition coefficient was determined in HPLC and was stated as < 0.3 – 2.83 mean (log Pow). (91% of the peaks revealed < 0.3).

The tested substance has a solubility of 22.74 ± 0.80 g/L at 20.0 ± 0.5 °C.

According to Annex VII of REACH Regulation 1907/2006, column 2 no surface activity is expected or can be predicted; therefore, the testing can be waived. As solid, the substance has no a flash point and the test can also be waived.

It is not expected to be auto-flammable, flammable, explosive and it is deemed to be potentially not oxidizing based on the chemical structure, the oxygen balance values and the known experience in the handling and use of the substance.