Under what condition may the U.S. EPA classify a pesticide as a restricted-use pesticide?

A pesticide may be classified as a restricted-use pesticide if it presents a significant dermal hazard. This classification is crucial as it aims to protect users and the environment from potential harm caused by misuse. When a pesticide poses serious health risks, especially through skin contact, it necessitates stricter regulations concerning its distribution, application, and handling to ensure safety.

The designation as a restricted-use pesticide also ensures that only certified applicators or those under their direct supervision can apply it, thereby reducing the risk of exposure to the general public and non-target species. Factors like user safety and environmental impacts are central considerations for the EPA when determining if a pesticide requires this level of restriction.

Other conditions listed, such as being ineffective unless used at double the rate, leaving visible residues, or not breaking down within a specified time, do not automatically trigger restricted-use classification. Instead, these factors may influence a pesticide's labeling or recommended use guidelines but don't inherently indicate a significant risk to human health or safety in the same way that a dermal hazard does.