This test method is of principal value in minimizing the number of animals required to estimate the acute oral toxicity (LD50).

This test method is inappropriate for materials typically producing death 2 or more days after administration of the test compound unless the observation time between dosages is increased. This test method can be successfully applied, however, for materials producing only an occasional death 2 or more days after administration.

The LD50 is valuable as a measure of the relative acute toxicity of a material and can be used to make an estimate of potential hazard to humans when pesticides, other chemicals, or mixtures are ingested.

This test method allows for observation of signs of toxicity in addition to mortality. This information can be useful in planning additional toxicity testing.

1.1 This test method determines the lethality (LD50 value) and signs of acute toxicity from a material using a limited number of rats. The technique used in this test method is referred to as the "Up-and-Down Procedure." This test method is an alternative to the classical LD50 test and is applicable to both liquids and solids.

1.2 This test method is not recommended for test materials which typically produce deaths beyond 2 days postdosing.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.