A measure of the ability of a chemical to cause injury or death from one exposure. The degree of exposure combined with the level of toxicity. The ability of a substance to cause injury or death if swallowed. The measure of the ability of a chemical to cause injury or death. Measuring Toxicity Toxicity, the capacity of a substance to cause injury, varies depending on the chemical.
Some chemicals are extremely toxic while others are essentially nontoxic.
However, large enough quantities of almost any substance can cause a toxic response. To understand the toxicity of herbicides, it helps to know how toxicity tests are conducted. This dosage is usually referred to in terms of the weight of the chemical and the weight of the test animal. Approximately 1 pint of Accord in the concentrated form would have to be ingested for a 175-pound person to reach the LD 50 dose. Table 1 gives toxicity categories for pesticides, and Table 2 provides LD 50 ratings for common herbicides.