Which fumigant is known to be highly flammable in air?

The correct answer to the question regarding which fumigant is highly flammable in air is actually Phostoxin. Phostoxin is a solid formulation that releases phosphine gas when it comes into contact with moisture. Phosphine is known for being flammable and can ignite in the presence of air, making it hazardous in terms of fire risk.

For context, methyl bromide is primarily a toxic gas used as a fumigant, but it is not classified as highly flammable. Vikane, also known as sulfuryl fluoride, is a non-flammable fumigant used in structural pest control. Carbon dioxide is an asphyxiant but is not flammable.

Understanding the properties of these fumigants is crucial for safe handling and application within pest control practices, particularly concerning the risks associated with flammable materials like phosphine.