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Physical & Chemical properties

Melting point / freezing point

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Description of key information

The extrapolated onset temperature of the melting of the read-across substance was seen to be at 35.9°C with decomposition beginning in the region of 73°C. A total mass loss of 96.5% was observed on heating to 600°C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:
35.9 °C

Additional information

The melting point and decomposition temperature of the registered substance was determined in accordance with a method equivalent to that of the OECD Guideline for Testing of Chemicals 102. Differential Scanning Calorimetry (DSC) was conducted to obtain the melting and decomposition temperatures and TGA was carried out to view the temperatures when the materials begin to decompose. The extrapolated onset temperature of the melting of the substance was seen to be at 35.9°C with decomposition beginning in the region of 73°C. A total mass loss of 96.5% was observed on heating to 600°C. In addition, an equivalent study was conducted to determine the melting point of the structurally similar substance, 6 -[(p-Tosyl)amino]hexanoic acid, compound with 2,2',2''-nitrilotriethanol (1:1) (Tosyl salt). The extrapolated onset temperature of the melting of the read-across substance was seen to be at 56.9°C with decomposition beginning in the region of 154°C. A total mass loss of 88.2% was observed on heating to 600°C. Read-across between the registered substance and the test substance (Tosyl salt) is considered justified owing to the structural similarity of the two substances. Both are salts of a carboxylic acid and triethanolamine. The acid components are structural isomers and differ only in the position of a single methyl group in the N-methyl salt. The test substance and the registered substance are expected to exhibit similar thermal behaviour, and have shown similarity in the results of other physical endpoints such as water solubility.