Which substance is typically NOT used as a fumigant?

Phosphorus pentoxide is typically not used as a fumigant because it primarily serves as a desiccant, a substance that removes moisture from the air, rather than as a pesticide or fumigant. Fumigants are gaseous pesticides used to exterminate pests in various environments, particularly within stored goods, buildings, and soil, whereas phosphorus pentoxide's main function is to absorb water, making it unsuitable for pest control purposes.

In contrast, substances like methyl bromide, phosphine, and sulfuryl fluoride are effective fumigants widely utilized for their ability to penetrate materials and eliminate pests such as insects and rodents. Methyl bromide is known for its effectiveness in a variety of agricultural and structural applications. Phosphine is commonly used for grain storage and pest control in various settings due to its efficacy against a broad range of pests. Sulfuryl fluoride is utilized in structural fumigation to target wood infestations and other pests.

Recognizing the distinct purposes of these substances helps clarify the specific role that each chemical plays in pest management, underscoring why phosphorus pentoxide does not fit into the category of fumigants.