Screening Tests for Reactive Chemicals

Screening tests are small-scale, safe experiments that provide information about hazards in a short time. It is always desirable to obtain higher quality information. We 

SC-DSC enables the estimation not only of reaction heat but also the ease of occurrence of the reaction, while the calculation method provides only the estimated value of the reaction heat. Moreover, samples can be tested in the early stages of their development, because the SC—DSC requires only a small quantity of sample, typically less than 3mg per test. 

A new method has recently been developed using DSC to predict whether a self reactive substance has the ability to propagate an explosion (See Chapter 3) 1 . In this method, by plotting the log of QDSC against the log of (TDSC-25), the ability of a substance to propagate an explosion can be judged by seeing on which side of a certain line the plot falls (See Fig. 1.2.). 

Hazards of reactive chemicals predicted by the result of SC-DSC are shown in Table 1.7. SC—DSC has been selected for use as a test to classify hazardous materials under 

Among hazardous reactive chemicals, special attention should be paid to those which easily explode by mechanical impact or friction. The use of these chemicals without knowledge of their characteristics inevitably leads to an accident These chemicals include Dibenzoylperoxide (BPO), 5—chloro-1,2,3-thiadiazole (5—CT),mixtures of chlorate and red phosphorus, and 2,4—dinitro- phenylhydrazine (DNPH). Appropriate handling procedures for these highly sensitive chemicals during preliminary evaluations must be established. 

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