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Melting point / freezing point

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Description of key information

Decomposition =  272- 361 °C

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:
349.84 °C

Additional information

Acid Red 249:1 is a multiconstituent substance composed by the acidic and the sodium salt forms of the same structure (72.7 % and 14.95 % of the substances respectively). EPI Suite v4.10 has been used in order to compare the two structures. The two results, derived from estimation of melting point by means of MPBPVP v1.43, are identical (349.84 °C both for the salt and for the acidic form) due to the great similarity between the two molecules.

Considering the great similarity of the molecules and the results of the estimation with EPI Suite v4.10, Acid Red 249:1 is expected to release water/solvent by imbition/cristallization starting from 25 -200 °C, followed by a decomposition of the product between 272- 361 °C (onset at 305.0 °C; enthalpy 138.6 J/g).

The smile notations used for the estimations are:


Sodium salt



Acidic form