Evaluation thermochemical hazard

The best way to evaluate thermochemical hazards will vary from one laboratory or plant situation to another depending on such factors as the stage of process development, the size of scale-up necessary, the equipment available, the time available for hazards review, and the amount of risk acceptable. 

Thermochemical hazard evaluation should be an integral part of any chemical process hazard review. This paper discusses how a pharmaceutical chemical development group performs thermochemical hazard evaluation through a combination of literature searches and physical testing. It will briefly discuss the physical testing methods and some of the philosophy behind them. 

The evaluation of potential thermochemical hazards should be an integral part of any chemical process hazard review. An uncontrolled release of heat during a chemical process operation can lead to problems that can vary from an inconvenient loss of a product batch to a devastating explosion. 

Our thermochemical hazard evaluation process begins as soon as a project or procedure is received by Chemical Development. We are trying to improve safety not only for the plant personnel but also for the process research chemists who will be developing the process in the lab. 

Our evaluation utilizes a combination of literature searches and physical testing. The literature search is a part of a comprehensive literature search for all types of biological and chemical hazards. It is performed by the chemist in charge of the project before any other work is started, and it is updated to include any changes as the process is developed. The literature sources used in these searches that are of interest for the identification of thermochemical hazards are listed in Table I. The Sandoz Ltd.,... 

The attempt in organizing the Symposium on Chemical Process Hazard Review at the Spring 1984 ACS national meeting in St. Louis, was to present papers on the review procedure, some of the thermochemical evaluation techniques and the application of both of these to actual processes. Some of the papers presented at the symposium have been collected and are published here to further exchange information related to conducting chemical processes "safely."... 

CHETAH is a tool for the preliminary screening of the reactivity hazards of organic chemicals. The evaluation is based on pattern recognition techniques using experimental hazard data and estimated thermochemical data. 

Frurip, D.J., Freedman, E. and Hertel. G.R.. 1989, A new release of the ASTM CHETAH programme for hazard evaluation versions for mainframe and personal computer, Int Symp on Runaway Reactions. 39-51 (CCPS, AIChE, USA). Benson. S.W., 1976, Thermochemical Kinetics. Methods for the Estimation of Thermochemical Data and Rate Parameters. 2nd edition (Wiley). 

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