FUMIGATION PROCEDUREFormaldehyde vapor is an extremely effective biocidal agent.  Fumigation is effective at above the temperature of 20ºC and relative humidity of 65%. Formalin is commercially available as 40% solution of formaldehyde in water. When formalin is heated formaldehyde vapor is generated.  hydrochloric acid and chlorine-containing disinfectants must beremoved from the room before fumigation.

Step 1: Preparation Thoroughly clean windows, doors, floor, walls,

surgery table and all washable equipments with soap and water.

Close windows and ventilators tightly. If any openings found seal it with cellophane tape or other material to avoid the leak of fume.

Switch off all lights, A/C and other electrical & electronical items.

Calculate the room size (surgical theater only) in cubic feet (L×B×H) and calculate the required amount of formaldehyde as given in step 3.

Step 2: Precaution Adequate care must be taken by wearing

cap, mask, foot cover, spectacle etc., Formaldehyde is irritant to eye & nose; and it

has also been recognized as a potential carcinogen.

So the fumigating person must be provided with the personal protective equipments (PPE).

Paste a warning notice on the front door indicating fumigation is in progress.

Step 3: Fumigation Electric Boiler Fumigation Method

(Recommended): For Each 1000 cubic feet, 500 ml of

formaldehyde (40% solution) added in 1000 ml of distilled water (if not available use tap water) in an electric boiler. Switch on the boiler, leave the room and seal the door. After 45 minutes (variable depending to volume present in the boils apparatus/its heating proficiency) switch off the boiler without entering in to the room (Switch off the main from outside)

Potassium Permanganate Method:  Here the heat generation is induced by an oxidizer -

Potassium permanganate (KMnO4), which results in auto boiling and generates fume from formaldehyde.  Take 500 ml of formaldehyde (40% solution) in 1000 ml of distilled water (if not available use tap water) in a heat resistant bowel, preferably in a steel bucket and then add 450gm of KMnO4 for 1000 cubic feet of theater volume. Repeat the same in separate bucket for every another 1000 cubic feet until it reaches the complete theater volume. It is important to add KMnO4 to all buckets simultaneously to reduce the exposure to fume (i.e., need 3 or 4 persons at different location).

After the initiation of formaldehyde vapor, immediately leave the room and seal it for at least 12 to 24 hours

Step 4: Neutralization

Before neutralization, formaldehyde fumigation system should be taken out from the surgical theater. Then the toxicity of formaldehyde vapor should be neutralized with ammonia solution.

Place a cotton ball and pour 300 ml of 10% ammonia (for each 500 ml of formaldehyde used) on the floor of surgical theater, at least 4 hours before (07 a.m.) the “Sterility Test”.

Formaldehyde gas reacts with ammonia gas and produce hexamine (synonym hexamethylenetetramine) which is considered a harmless substance.

Switch on the A/C, at least 2 hours before (09 a.m.) the “Sterility Test”.

Example:

Surgical Theater Volume = L×B×H = 20 × 15 × 10 = 3000 cubic feet

Note: Make it into nearest 1000, if the volume is in fractions

Formaldehyde required for fumigation = 500 ml for 1000 cubic feet

= So, 1500 ml of formaldehyde required (to be diluted in 3000 ml of distilled water)

Ammonia required for neutralization = 300 ml of 10% ammonia for 500 ml of formaldehyde

            = So 900 ml of 10% ammonia required

MICROBIOLOGICAL MONITORING OFOPERATION THEATRE. Swabbing and culture for bacterial and

fungal organisms should be requested for once in every three months and/orwhenever an outbreak is suspected, whenever there is somerenovation work done in the OT complex

Interpretation of Microbiological monitoring culture reports:

Most important parameters are:· Bacterial/fungal spore counts in air.· Surface bacterial / fungal counts on the OT table and its vicinity.· Routine screening for Clostridium tetani has lost its relevance and should be done only when suspected tetanus case is operated or whenever there is some renovation work done in the OT complex.

1. Results of pre fumigation microbiological monitoring indicates the prevalent bacterial load to which the patient could be exposed.

2. Results of post fumigation microbiological monitoring indicates the effectiveness of the fumigation procedure

Air Samples Average colony count per plate/30min

InterpretationAction to be taken.

Less than 10 bacterial colonies- Acceptable >No special action. Maintain regular fumigation and Mopping.

More than 10 bacterial colonies- Unacceptable >Repeat fumigation with microbiological monitoring.

Isolation of any number of colonies of Staphylococcus aureus and Pseudomonas species.- Unacceptable >Repeat fumigation with microbiological monitoring. > Follow the precautions given under heading IV

More than 2 Fungal colonies- Unacceptable >Repeat fumigation & thorough cleaning of all the objects intimate with the patient using70% Alcohol. See for any obvious fungal growth on walls and ceiling

Surface Samples Colony count per square feet.

InterpretationAction to be taken

Area (A)I.e. OT table and area adjacent to it.

Less than 5 colonies- Acceptable >No special action. Maintain regular fumigation and Mopping

5-9 Colonies- Undesirable >Follow the precautions given under heading IV. Maintain regular fumigation and Mopping.

≥10 colonies- Unacceptable >Repeat fumigation with microbiological monitoring

Area (B) I.e. area away from the OT table.

<19colonies>No special action. Maintain regular fumigation and Mopping

≥20colonies- Unacceptable >Repeat fumigation with microbiological monitoring

IV. Precautions taken to keep low bacterial counts

in operation theatre 1. Allow only those who are absolutely needed to be in

the operation theatre

2. Maintain in and out movements as minimum as possible

3. Prompt disposal of OT waste outside the OT complex.

4. Use of 10% sodium hypochlorite solution to clean blood and body fluid spillages.

5. Frequent and proper hand washing saves many lives.

6. Check for hand washing solution which should ideally have a combination of phenolic compound and a surfactant ( alcohol with chlorhexidine, chlorlheximide 2% or 4%, povidone iodine 7.5% or triclosan 1% etc).7. Request for inspection/cleaning of A/C ducts should be made every 3rd month.

Bacillocid fumigation fumigation can be doe using 2%

bacillocid . The room must be closed for 6 hours before use by housekeeping personnel.

Fumigation is done only in the high-risk areas like ICU,PICU,NICU,LABOUR rom; OT, wards are excluded for fumigation ( done only if required )

Surface cleaning for the wards may be done using 2% bacillocid of water.