In 40 CFR 156.62, the EPA established four Toxicity Categories for acute hazards of pesticide products, with "Category I" being the highest toxicity category (toxicity class). Most human hazard, precautionary statements, and human personal protective equipment statements are based upon the Toxicity Category of the pesticide product as sold or distributed. In addition, toxicity categories may be used for regulatory purposes other than labeling, such as classification for restricted use and requirements for child-resistant packaging.
In certain cases, statements based upon the Toxicity Category of the product as diluted for use are also permitted. A Toxicity Category is assigned for each of five types of acute exposure, as specified in the table below.[citation needed]