Thermal Stability: A Review of Methods and Interpretation of Data

The assessment and understanding of thermal instability associated with process materials is a prerequisite for safe manufacturing. This is particularly true for materials exposed to elevated temperatures during processing. Information gathering on thermal stability should commence as early as possible in the process development lifecycle such that, initially, highly energetic substances can be identified and handled accordingly. Further studies to accurately define safe exposure temperatures should then be performed using equipment and methods specifically appropriate to the plant or processing technique selected, or envisaged, for scale-up. A simplified procedure for thermal stability assessment is proposed which takes into account decomposition and oxidation activity which are both commonly observed with organic substances. The strengths and weaknesses of individual test methods are reviewed, and information is provided on correct application of the resulting data.