Reaction mass of Limestone and calcium fluoride and calcium sulfate

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the melting point is above 300°C

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING

In accordance with column 2 of REACh Annex VII 7.5, the study does NOT need to be conducted if the melting point is above 300 °C.
As presented under Section 4.2, melting expected in the range 825 - 1460°C for the test substance, with prior vaporisation of water anticipated.
Therefore no additional information is required.

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Melting expected in the range 825 - 1460°C for the test substance, with water decomposition followed by partial decomposition of one consituent of the reaction mass.

No experimental study is available on the registered reaction mass.

However, reliable literature data is available for the three constituents. For simplification purpose, a single reference was presented in this dossier for each constituent: the value was selected based on reliability of the data source, and when equivalent, where more information was provided.

Calcium fluoride and calcium sulfate melt respectively at ca 1403°C and 1460°C; calcium carbonate will decompose from 825°C, or higher depending on its crystal structure.

Assuming that the solid-to-liquid transition will follow the behaviour of the constituents, the reaction mass is expected to melt in a multi-phase range. Indeed, the test substance contained water. So, upon heating, vaporisation of this impurity is anticipated, followed by the reactions the decomposition of the calcium carbonate. Therefore no single value can be retained as key for purpose of CSA.

Moreover, it should be noted that experimental testing would be difficult to perform, considering that the applicability range of the different methods cited in the OECD guideline goes only up to 1273 K (i.e. 1000°C) in the best case. This means that for higher temperatures, testing would not be technically feasible, or result would have limited accuracy.