Fumigation is a method of pest control that completely fills an area with gaseous pesticides—or fumigants—to suffocate or poison the pests within. It is utilized for control of pests in buildings (structural fumigation), soil, grain, and produce, and is also used during processing of goods to be imported or exported to prevent transfer of exotic organisms. This method also affects the structure itself, affecting pests that inhabit the physical structure, such as woodborers and drywood termites.

The Process
Fumigation usually involves the following phases: First the area to be fumigated is usually covered to create a sealed environment; next the fumigant is released into the space to be fumigated; then, the space is held for a set period while the fumigant gas percolates through the space and acts on and kills any infestation in the product, next the space is ventilated so that the poisonous gases are allowed to escape from the space, and render it safe for humans to enter.

Chemicals Used

Methyl bromide was among the most widely used fumigants until its production and use was restricted by the Montreal Protocol due to its role in the theory of ozone depletion.

Widely used fumigants include:

phosphine
1,3-dichloropropene
chloropicrin
methyl isocyanate
hydrogen cyanide
sulfuryl fluoride
formaldehyde
Iodoform

Safety

Fumigation is a hazardous operation. Generally it is a legal requirement that the operator, carrying out the fumigation operation, holds official certification to perform the fumigation as the chemicals used are toxic to most forms of life, including humans.[1]

Post operation ventilation of the area is a critical safety aspect of fumigation. It is important to distinguish between the pack or source of the fumigant gas and the environment which has been fumigated. While the fumigant pack may be safe and spent, the space will still hold the fumigant gas until it has been ventilated.