Toxicity class

Pesticide classification system

Toxicity class refers to a classification system for pesticides that has been created by a national or international government related or sponsored organization. It addresses the acute toxicity of agents such as soil fumigants, fungicides, herbicides, insecticides, miticides, molluscicides, nematicides, or rodenticides.

Assignment to a toxicity class is based typically on results of acute toxicity studies such as the determination of values in animal experiments, notably rodents, via oral, inhaled, or external application. The experimental design measures the acute death rate of an agent. The toxicity class generally does not address issues of other potential harm of the agent, such as bioaccumulation, issues of carcinogenicity, teratogenicity, mutagenic effects, or the impact on reproduction. Regulating agencies may require that packaging of the agent be labeled with a signal word, a specific warning label to indicate the level of toxicity.

The Indian standardized system of toxicity labels for pesticides uses a 4 color system (red, yellow, blue, green) to plainly label containers with the toxicity class of the contents.

The United States Environmental Protection Agency (EPA) uses four toxicity classes in its toxicity category rating. Classes I to III are required to carry a signal word on the label. Pesticides are regulated in the United States primarily by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

Furthermore, the EPA classifies pesticides into those anybody can apply (general use pesticides), and those that must be applied by or under the supervision of a certified individual. Application of restricted use pesticides requires that a record of the application be kept.