What is the definition of fumigants in pesticide terms?

Fumigants are defined as pesticides that create poisonous gases, which is why this option is the correct choice. These substances are used primarily to control pests in enclosed environments, such as buildings, grain bins, and soil. When applied, fumigants penetrate materials and effectively eliminate pests by delivering a highly toxic gas that can disperse throughout the area, reaching pests that may be hidden or difficult to access.

The mechanism of action differentiates fumigants from other pesticides; they often do not require direct contact with the pest in their conventional form but rather function as a gas that can permeate various materials. This makes them particularly effective for controlling a wide range of pests, including insects and rodents.

In contrast, pesticides that are applied in dry form, liquid-based pesticides, and those requiring mixing with water describe other application methods and formulations that do not align with the definition of fumigants. These alternatives focus on different delivery methods and target pest control scenarios, which do not involve the gas phase characteristic of fumigants.