No Bakery Products. How Did That Happen?

A flour mill on a tropical island was shut down due to a surprisingly high level of insect activity. The company called a food protection expert requesting assistance for the mill and bakery facility. It was the only commercial bakery on the island and would be without flour in a few days. No bakery products on a tropical island. How did that happen?

Although this incident may be fictitious with any similarity to real events purely coincidental, there are lessons to be learned: How did this infestation reach such a high level? How does one eliminate an insect problem in a timely manner? What are some lessons learned?
 

The investigation started with a walkthrough to determine the level of infestation and observe the sanitation and pest management program. Examining the bakery’s sifter-tailing records of inbound flour indicated an increasing presence of adult beetles. The insects were identified as confused flour beetles and were observed in multiple life stages. At the time of the investigation, the mill was not in operation, and employees were cleaning with brushes, brooms, and small vacuums.

Further investigation showed that flour from the storage bins was flowed through a 30-mesh sifter. However, lighted magnification examination of tailings was not within the bakery’s procedures, and flour-beetle larvae were present in the sifter tailings. The flour mill was also using a 30-mesh screen for final sifting prior to packing and pneumatic delivery to the bakery.

Cosmetic cleaning of the flour mill was conducted more for worker safety than for food safety. The bins were cleaned monthly with sifter maintenance weekly. Access to key equipment, pipe transitions, and storage bins was limited. Industrial vacuums were not observed in the facility. Deep cleaning was not scheduled and was actually based upon available time during the monthly shutdown. Pest management was conducted in-house with a regular monthly shutdown approach for cleaning and fumigation. Records indicated that the same pesticides had been used for years.

The bakery’s sanitation program was at a higher level than that of the flour mill, helping to prevent the infestation from expanding into the bakery operation.

The Cause. Warm humid conditions allow for optimum development (less than a 30-day cycle) of confused flour beetles. The insect population at this mill was due to an ineffective cleaning program, a lack of equipment access (sanitary design), and insect resistance to pesticides.
 

The Solution.The bakery acquired industrial vacuums to deep clean the flour receiving and storage system. Flour was imported briefly, allowing the mill to be restored to a cleaner insect-free operation. A lighted magnification procedure was implemented for flour-tailings examination.

The flour mill modified its process to improve foreign-material control with a final 40+ mesh sifter and examination of outbound flour tailings with lighted magnification. Entoletion and metal-detection equipment were installed. Access to equipment, bins, and transitions was provided allowing a timelier deep cleaning. The sanitation program was modified using a master cleaning schedule. Industrial vacuums were used, and a central vacuum system installed for more effective overall cleaning. A professional, experienced pest management company was hired. The flour mill was heat treated and, along with deep cleaning, was returned to an insect-free condition within a week. The monthly shutdown schedule was continued for cleaning and maintenance. Heat treatment for insect control was conducted every three months. An approved-pesticides list was used with the pest management company rotating pesticides.

Lessons Learned. Although the same company operated both production operations, a formal customer food safety audit was implemented at the flour mill, with the bakery as the customer. Through the program, the bakery helped provide quality assurance and food safety guidance for the flour mill. Low-moisture food-production plants that use vacuums are cleaner and more insect free than those that don’t use suction cleaning.

Applying the same pesticides in a not-so-clean environment is a formula for ongoing insect problems. Pesticides must have an approved list and be applied on rotation. Heat treatment for insects is a reasonably quick tactic to eliminate established insect populations, especially in tropical environments or smaller tropic-like environments in food plants.

Another lesson learned was establishing one sanitation department for the entire facility inclusive of grounds, rather than having small departments within the production departments of the two operations. The in-house pest management personnel were merged into sanitation providing an educated set of “pest” eyes.
 

Conclusion. Sanitation and pest management is critical for food safety, and even more so in the tropics. Designing food safety and pest management proactively is more effective than doing it reactively, especially in a crisis mode. Long-term planning with properly conducted modifications can have a long-term impact and provide a more effective, efficient, and profitable operation.