BUILDING TERMINAL BIOSECURITY PROGRAMME
DISEASE PREVENTION IN SIX SIMPLE STAGES
1. REMOVAL OF EQUIPMENT AND DRY CLEANING
The removal of all gross organic matter is essential because debris contains high levels of contamination and is a major source of infection.
- Remove trays, pots, containers and equipment from the area to be disinfected and put to one side for cleaning.
- Using a stiff brush, fork, shovel, etc., remove all gross organic matter and debris from the building.
2. PRE-CLEANING SURFACES & EQUIPMENT
- Following any dry cleaning process, use a multipurpose heavy-duty cleaner (Biosolve™ E for degreasing and Biofoam™ for descaling surfaces) to remove soiling from all surfaces and to ensure deposits of organic matter do not remain.
- Depending on the degree and type of soiling prepare either a 1:200 (0.5%) or 1:100 (1%) solution of either Biosolve™ E or Biofoam™.
- Apply with a knapsack sprayer or pressure washer.The pressure washer should be set on a low pressure setting 500psi (35 bars) using a 45° angle jet. The application rate should be 500 mls per m2 of surface area.
- Start at the apex of the roof and work down the walls to the floor, paying particular attention to corners and other areas where dirt accumulates. Caked soiling should be brushed if necessary to aid removal.
- Allow at least 15 minutes for the detergent to penetrate and loosen soiling from all surfaces before rinsing at high pressure with clean water. Where possible, allow surfaces to dry before disinfection.
3. MOVABLE EQUIPMENT & TOOLS
Equipment removed from buildings can carry heavy pathogenic contamination if not thoroughly cleaned and disinfected. This can lead to carry over of infection from one building to another, or could reintroduce infectious organisms back into the building or contaminate food produce being packed.
Pre-cleaning of moveable equipment & tools
- Using a stiff brush, remove all gross organic matter from equipment, tools and utensils.
- Depending on the degree of soiling, prepare a 1:200 (0.5%) or 1:100 (1%) solution of either Biosolve™ E or Biofoam™ to wash or dip equipment including trays, pots and containers allowing time for the solution to penetrate and loosen dirt before rinsing with clean water.
- Allow to dry.
Disinfection of moveable equipment & tools
- Using Virkon™ H at a dilution of 1:100 (1%) wash or dip equipment in the disinfectant solution.
- Leave for at least 30 minutes before rinsing with clean water and then allow to dry.
- Store equipment away where it will not be contaminated.
4. WATER DELIVERY & IRRIGATION SYSTEMS DISINFECTION
All water systems can contain some infectious contaminants, especially header tanks where dust and dirt can accumulate.
To combat infectious micro-organisms and break down biofilms and algae that may cause blockages in the water delivery and irrigation system pipes, use Virkon™ H at a dilution of 1:100 (1%) when carrying out the terminal biosecurity program. Add the appropriate amount of Virkon™ H powder to the header tank, then run the solution through the pipes until it fills the entire water delivery / irrigation system. After 4 hours, drain the entire system and then flush through thoroughly with clean water.
At the terminal disinfection stage, biofilm build-up within irrigation lines is a known issue of concern, we recommend a longer contact time to address this challenge.
5. DISINFECTION OF PRE-CLEANED SURFACES
The level of infectious micro-organisms present after precleaning could still be high enough to offer a disease challenge to personnel. The use of a broad spectrum disinfectant active against viruses, bacteria, yeasts, moulds is essential to help break the chain of infection.
- For routine disinfection of depopulated greenhouse structures, farm, food packing or storage building surfaces, apply Virkon™ H at a dilution of 1:100 (1%) and apply at a rate of 300 mls per m2 of surface area.
- Use a knapsack sprayer or pressure washer at 35 bars (500psi) with a 45° spray head.
6. COLD MISTING & THERMAL FOGGING DISINFECTION
When the depopulated greenhouse or farm building has been thoroughly cleaned and disinfected, all moveable equipment and tools should be returned. To disinfect inaccessible areas that might have been overlooked, the building should either be aerial misted or thermally fogged.
Use Virkon™ H at a dilution rate of 1:100 (1%) and spray into the apex of the depopulated building using a very fine mist from a suitably pre-set pressure washer or mechanical misting machine.
Use Virkon™ H at a dilution rate of 1:25 (4%, dissolved in 90:10 water: Virkon™ Fog Enhancer) and apply using a thermal fogging machine.
Fogging with Virkon™ H is safer and more effective than traditional methods with aldehydes for personnel, as the building can be entered soon after, once mist has fully dispersed, keeping downtime to a minimum.