Theforegoing sections have introduced the various classes of hazardous chemicals,their hazard criteria, effects they exert on human health, and the technicalmeasures that one may adopt in order to contain and / or mitigate theassociated danger in working with them. Thus it may be appropriate to summarizethe entire process of hazard identification and management by means of layeredor step-by-step scheme. Such a decision tree is presented in fig. 1. Itis expected to provide a structured approach to selection and admittance of achemical for use in laboratory research.