Fumigation is the most commonly used method for pest control and elimination. It involves the use of pesticides or pest retardants in gaseous form, referred as fumigants, to poison pests in a residential area, business complex or public space that has been infested. Fumigation is also used in agriculture or grain produce to prevent the soil being infected or during import and export of goods to get rid of insects, worms and organisms that might be transported from place to place. While excessive use of chemicals in any form is to be avoided because it may harm human life or structural buildings, the process is not entirely effective in pest elimination, it merely prevents the pests making their presence once again in the same area.
The fumigation process is usually done in a phased manner. As a first step, the entire area that needs fumigation is sealed off or covered. Next, the area is fumigated, i.e. the chemicals are released in the covered space which may be a home, an office, a warehouse or storage complex, underground cellar, ship cargo containers, etc. In the third phase, the fumigant is allowed time to completely fill the enclosed space and kill the pest itself (woodborers, termites) or pest infestations (eggs, larvae). fumigacioneslascondes.cl Finally, the area is ventilated with fresh air and sunlight so that no trace of the chemical or gas is left behind. Once this process is completed and thorough inspection is done, the area is certified ‘pest free’.
Chemicals used in fumigation
Until the Montreal Protocol, an international treaty signed in the late 1980s to protect the Ozone layer of the atmosphere from depletion, was signed the random use of many chemicals was widespread. The widely used fumigant at the time was Methyl Bromide; its production and use were restricted later.
The list of fumigants in use includes:
• Sulfuryl Fluoride
• Methyl Isocyanate
• Hydrogen Cyanide
Methods of fumigation
Broadly, fumigation methods can be categorized into surface and sub-surface. Surface treatments refer to fumigation done on exposed surface areas. Sub-surface refers to treatments where gases or chemicals have to be applied into spaces like soil, cargo containers and storage tanks etc. Sub-surface fumigation methods are:
• Short Probe
• Long Probe
The methods adopted for surface fumigation depend greatly on the situation, circumstance and the nature of pest and pesticide. For homes, the ‘Tenting Method’ is used, where a rubber tent is placed to seal off the area. In larger structures like entire buildings, other options that take into account the size of the building and infestation come into play.
Fumigation has to be done in an extremely non-hazardous manner and the agency or operator who carries out the process has to be a certified authority with knowledge of the chemicals and how they can be used so as to ensure maximum safety to life and property. The area of knowledge comprises the proportion of fumigant to be used in relation to the area, type of fumigant, time duration for fumigation to take effect and complete ventilation post-fumigation.