Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information


Reactive Blue 221 (RBl221) is a blue organic solid at 1013 hPa and 20 °C, generally marketed and used in powdered form. Particle size distribution showed that RBl221 is characterized by d(0.5) of 61.015 µm.

Relative density has been determined by means of a pycnometer and has been recorded 1.786 at 20 °C.

Based on structure, the surface activity is nor expected or predicted. Since it is a solid and on the basis of the physicochemical properties, vapour pressure, surface tension and flash point can be neglected; viscosity is technically not feasible.


The differential scanning calorimetry method has been used for the evaluation of melting and boiling points of the test substance. No endothermic peak corresponding to melting and boiling of the test substance was recorded in the tested temperature range from 25 to 440 °C. Between 25-120 °C an endothermic effect was observed, due to the imbibition water/solvent release. Decomposition was recorded between 283 - 440 °C (onset at 327.1 °C, enthalpy of 250.4 J/g).


RBl221 is very soluble in water (196.41 g/l at 20 °C and pH 4.08). The affinity of RBl221 with the n-octanol phase is very low, as determined in the partition coefficient test, performed following the OECD 107 by shake flask method. The logPow resulted lower than -2 (-2.5209 at 20 °C and at pH of 4.07); despite the values recorded are outside of the applicability domain for the test method, the results of partition coefficient determination can be considered as reliable and representative for the tested substance. The study outcomes are indicative of a high affinity with the water phase, respect to the octanol one.



RBl221 does not ignite and propagate combustion. The substance contains groups associated with explosive properties, but it decomposes at a temperature below 500 °C (i.e. 327.1 °C), with an energy less than 500 J/g (i.e. 250.4 J/g), thus, according to the preliminary screening procedures described in the Annex VI, section 3, of the UN Recommendations on the Transport of Dangerous Goods Manual of Tests and Criteria, an explosive potential is not expected.

RBl221 does not meet the criteria to be considered as flammable/explosive/oxidising.