Ronald D. Sebastian
Milling Technical and Mechanical Specialist Consultant
“With today’s stringent requirements by the FDA and food safety organizations, together with external auditing by the clients, millers are required to deliver safe food without the threat of infestation. Maintaining housekeeping and daily routine inspection of the plants and prioritizing work that needs to be done with an emphasis on leaks will surely help any good miller to control infestation in his/her plant.”
Infestation is a millers’ greatest challenge. This is one aspect in the mill that has a miller running around and at times pulling out his hair. This is because infestation leads to many returns to the mill and often can result in losing good customers and can even lead to questions about the companies’ integrity. With today’s stringent requirements by the FDA and food safety organizations, together with external auditing by the clients, millers are required to deliver safe food without the threat of infestation. The practical way to overcoming the issue is to properly clean the mill and all associated equipment.
Most mills today, hire outsourced cleaning teams for this function, a function that requires the team to know and understand the effect of deep cleaning as well as surface cleaning. In most cases, this team is not thoroughly trained and do not understand the impact their performance has on the facility.
It is often claimed that wheat being brought to any milling facility is insect-free. The question to be asked is, “Where then do the insects come from?” If not from the grain, then where? Most grain pest controllers claim that to prevent infestation more regular pesticide application and fumigation needs to be done. From a professional miller and pest controller’s perspective, I am absolutely certain that the method that I apply works.
Cleaning! We all know is 98% of pest control while application accounts for the other 2%. When a mill is stopped for miller’s maintenance, and the miller avoids deep cleaning, one can expect to find infestation again and again.
One of the main contributors to re-infestation is the exhaust systems in the mills and on the top of our flour bins, which are more often than not, forgotten when maintenance is being done.
The following areas need to get the millers' attention every time, to prevent the development of insect pests.
Tabulated are the areas that must be checked and cleaned regularly;
1. Application of fumigant during intake to ensure that their development is curbed.
2. Exhaust trunking throughout the plant.
3. All screens room equipment with course and fine screenings being moved out of the mills daily.
4. Collecting conveyors, in the dead spots created by the ganger bearings and the empty space at the head and tail ends of the conveyors.
5. Plansifter doors, in the plush seal applied to the sides of the vertical clamping door; in the wire mesh backing wire securing clamps on older plansifters; under the collecting trays if not properly cleaned; in the inlet and outlet sleeves; on the sides of the horizontal clamping box at the top of the sifter. These are often not cleaned at all.
6. The tensioning slots of the purifier sieves; aspiration channel; inside the main control valve housing; between the purifiers at the lighting section.
7. Dead spots of tube screw conveyors where the insects really thrive.
8. Cracks and crevices in the buildings where the insects thrive due to the millers not identifying them as potential harborage.
9. Under feed rolls of the roller mills as well as the dead spots in the feed tubes and feed boxes, if this is not thoroughly cleaned out regularly. Inside of the feed guide plate above the back grinding roll where insects accumulate
10. Inside of the feed box where the dust accumulates and is left for long periods.
11. Covers of the flour collecting conveyors that are difficult to reach. Removing occasionally for thorough cleaning will assist with control.
12. Inside the distribution hoppers of the raw wheat and conditioning bins where the stock does not reach.
13. Spout bends where moth develops especially in the stock distribution spouting out of the plansifters.
14. Flour holding and packing bins must be cleaned at least every quarter to remove attrition flour from the roof of the bins. All tube screws should be retracted and cleaned. Aspiration filter covers of the hoppers must be replaced regularly or washed and replaced.
15. Joints in the trouser legs of packing bins where the insects can develop.
16. Mixers and blenders together with the additive mixers.
17. Packing machines must be thoroughly cleaned and sanitized weekly.
18. All distribution hoppers above blow thru airlocks.
19. Bran and pollard packing and receiver bins quarterly cleaning are essential.
20. Pallet cleaning with a high-pressure washer will remove any adhering eggs that might be returned from clients’ warehouses.
The regular contact insecticide spraying of potential harborage areas in the mills and flour bin tops and bottoms. Spillage must be cleaned up and mixed away on the shift on which they occur. Fogging on the wheat silo basements and tops as well as warehouses and the plants will help curb the development of flour moths and other insects. Millers must not leave any spillage lying around in the screens rooms and mixing areas.
Maintaining housekeeping and daily routine inspection of the plants and prioritizing work that needs to be done with an emphasis on leaks will surely help any good miller to control infestation in his/her plant.
Only you can keep your plant infestation free.