Which section under FIFRA could be used to allow the use of an unregistered pesticide to control an "emergency" pest problem?

The use of an unregistered pesticide to address an "emergency" pest problem is specifically covered under Section 18 of FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act). This section allows the Environmental Protection Agency (EPA) to grant a special permit for the use of a pesticide that is not registered for a specific purpose if there is a significant pest emergency.

This provision is utilized when a pest problem arises unexpectedly and poses a serious threat to public health, agriculture, or the environment, necessitating immediate action. It ensures that certain unregistered pesticides can be used on a case-by-case basis, provided that the pesticide is deemed effective for the situation and poses manageable risks.

The other sections mentioned do not provide the same level of flexibility for unregistered pesticide use in response to emergencies. For example, Section 3 generally concerns the registration of pesticides before they are marketed or used and does not offer provisions for unregistered products. Therefore, Section 18 is key in allowing effective and timely control of serious pest issues when conventional options are unavailable.