Acute and Subchronic Toxicity Tests

The various national and international regulatory authorities have used different hazard classification systems in the past. In light of the importance of hazard classification, the Organisation for Economic Cooperation and Development (OECD) recently harmonized criteria for hazard classification for global use. For example, the five harmonized categories for acute oral toxicity (in mg/kg body weight) are 0-5, 5-50, 50-300, 300-2000, and 2000-5000. 

As a result of much recent controversy, the LD50 test has been the subject of considerable regulatory attention and as a result changes in requirements have been promulgated. These changes are intended to obtain more information but, at the same time, use fewer animals. 

Criticism of the LD50 Test. The criticisms of the test include  

Support of the LD50 Test. Continued use of the test has been advocated, however, on the grounds that it is of use in the following ways  

For the previously listed reasons, there has been a concerted effort in recent years to modify the concept of acute toxicity testing as it is embodied in the regulations of many countries and to substitute more meaningful methods that use fewer experimental animals. The article by Zbinden and Flury-Roversi is an excellent summary of the 

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