Some of the industrial disasters which have occurred in recent times have highlighted the need for knowledge of the toxicity of compounds used in industry as well as for drugs and food additives. This knowledge is essential for the development of effective and rapid treatment of the toxic effects, just as it is essential for the treatment of overdoses and accidental poisonings. For example, one of the worst industrial disasters occurred at Bhopal in Induction 1984 where a factory manufacturing the ticide carbaryl leaked a large amount extremely noxious compound methyl isocynate (Figure 1.3). Little was known of the toxicity of this compound and consequently treatment of the victims was uncertain and possibly inadequate.
Another major reason for testing chemicals in toxicity and other studies is so that they may be classified according to hazard such as toxic explosive or flammable. This will then enable decisions to be made about marketing and labelling. So we are exposed to toxic or potentially toxic compounds in many ways in our daily lives and toxicology is clearly a subject of great importance in society. This becomes apparent when we look at the types of poisons and the ways in which we are exposed to the Indeed, the categories cover virtually all the chemicals one might expect to encounter in the environment. After consideration of this one might well ask are all chemicals toxic? The following phrase perhaps provides an answer: there are no safe chemicals, only safe ways of using them.