Fumigation: Definition, Requirements, Preparation, Procedure,applications

Fumigation: Definition, Requirements, Preparation, Procedure and Applications

Definition of fumigation

Fumigation is a process where fumigant, a chemical at required temperature and pressure can exist in a gaseous form in sufficient concentration will be lethal to pest organisms. It is a very useful method to control insect pests, diseases,s, and nematodes. But in reference to the medical field, it uses for the reduction of microbial agents ( bacteria, fungi, virus) on hospital surfaces and to control surgical site infections as well as for areas where microbiological cleanliness is required.

Requirements for fumigation

Personal Protective Equipment (PPE) set that includes face protection, goggles and mask or face shield, gloves, gown or coverall, head cover, and rubber boots.
Formalin/ saturated formaldehyde solution (37%)
Distilled water (D/W)
Electric boiler
Potassium permanganate
Ammonia

Choosing formaldehyde as a fumigant for hospital setup

Formaldehyde fumigation has long been an accepted method for areas where microbiological cleanliness is required because of the following properties-

Low-temperature heating produces vapor.
The vapor phase decontaminates the air i.e. environment.
It kills vegetative bacteria/spores.
When formalin is mixed with water and exposed to elevated temperature
Gaseous formalin is generated.
To sterilize the operation theater, ICU/NICU rooms, or areas where microbiological cleanliness is required.
Formaldehyde gas (bactericidal, sporicidal, viricidal) is widely employed as it is cheaper for sterilization of huge areas like operation theaters.
Formalin kills the microbes by alkylating the amino acids and sulfhydryl group of proteins and purine bases. In spite of the gas being hazardous continues to
be used in several developing countries.

Preparation prior Fumigation

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 space is held for a set period while the fumigant gas percolates through space and acts on and kills any infestation in the product.
Next, space is ventilated so that the poisonous gases are allowed to escape from the space, and render it safe for humans to enter.

Fumigation Procedure

Thoroughly clean windows, doors, floor, walls, and all washable equipment with soap and water.
Close windows and ventilators tightly. If any openings are found seal it with cellophane tape or other material.
Switch off all lights, A/C, and other electrical electronic items
Calculate the room size in cubic feet (Length X Breadth X Height) and calculate the required amount of formaldehyde as given in.
Personal care during fumigation: Adequate care must be taken during wearing PPE that includes face protection, goggles and mask or face shield, gloves, gown or coverall, head cover, and rubber boots. (Note- Formaldehyde is irritant to the eye nose and it has been recognized as a potential carcinogen. So the fumigating employee must be provided with the personal protective equipment.)
Creating the Formaldehyde gas:-Electric boiler fumigation method for every 1000 cubic feet of the volume of the operation theater-500 ml of formaldehyde (saturated i.e. 37% ) added in 1000 ml of water in an electric boiler. Switch on the boiler, leave the room and seal the door. After 45 minutes (variable depending on volume present in the boils apparatus) switch off the boiler without entering into the room.

Another Method of Fumigation

In principle, we have to generate formaldehyde gas. It can be performed by the most easier way to mix the needed quantity of formalin to water and heating at lower temperatures at 80°C to 90°C. It can also be done with the addition of formalin to potassium permanganate. Adding potassium permanganate to formaldehyde. This method is for every 1000 cubic feet, add 450 gm of potassium permanganate (KMnO4) to 500 ml of formaldehyde (37%). Take about 5 to 8 bowels (heat resistant place it in various locations) with equally divided parts of formaldehyde and add equally divided KMnO4 to each bowel. This will cause auto-boiling and generate fume. After the initiation of formaldehyde vapor, immediately leave the room and seal it for at least 48 hours.

Neutralization of Fumigation

Neutralize residual formalin gas with ammonia by exposing 250 ml of ammonia per liter of formaldehyde used. Place the ammonia solution in the center of the room and leave it for 3 hours to neutralize the formalin vapor. e.g. Operation theater volume ( length 30 ft., breadth 20 ft. and height 10 ft.) 6000 cubic feet and then formaldehyde required for fumigation 500 ml for 1000 cubic feet So, 3000 ml of formaldehyde required. Ammonia is required for neutralization 150 ml of 10% ammonia for 500 ml of formaldehyde So, 900 ml of 10% ammonia is required.

Alternative chemical agents needed in-hospital use having the following properties-

A need for aldehyde-free based chemicals is a growing concern. e.g. brand name ‘Hospital-Aero’ -Aldehyde free Aerosol Disinfectant for fogging

Need for quicker sterilization methods with ever-increasing work loads.
Need for non-toxic safe agents.

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