Salmonella in Pet Food. How Did That Happen?

Around 6:00 a.m. a security guard called a pet food plant’s lead supervisor about the FDA arriving with two vehicles. All investigators were escorted to the plant’s visitor lobby; their credentials were checked and recorded; and they were informed that the plant manager would arrive shortly. During the opening meeting the FDA announced that they were investigating a sick child’s illness due to Salmonella allegedly sourcing from pet food produced at this plant. 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 does one manage multiple FDA investigators on site? If there is Salmonella in the plant and/or in the product, where is the food safety gap? How is the gap corrected? What are practical solutions for preventing such an incident from happening to you?

The Investigation. The investigation started with an examination of the company records of Salmonella testing in both the plant environment and products. Sampling protocols and testing procedures were reviewed. One team of FDA investigators sampled numerous environmental locations within the plant while the other team sampled specific finished products. Each of the FDA investigators was shadowed by a company supervisor/manager with all samples duplicated for company analysis. Finished products that were sampled were placed on a precautionary hold pending test results.

Company test results of the duplicate samples indicated a low incidence of environmental positive Salmonella in the raw material zone along with finished-product-negative Salmonella. These results mirrored historical company records. The FDA test results indicated a moderate incidence level of positive Salmonella in the raw material zone along with additional positive Salmonella findings in the processing and further processing areas. In addition, test results of finished product indicated a low incidence level of finished products matching serotype with the product of investigation. How did that happen?

The Cause. Examining the two testing procedures step by step identified that the company’s procedure lacked a neutralization step creating an acidic nutrient.

The Solution. The pet food company corrected the error, verified the serious problem, recalled/destroyed suspect products, initiated a hold/test/release policy, formed a Salmonella elimination task force and implemented an in-plant microbiological laboratory. Based on extensive test results, the task force directed a redesign (more segregation) of the plant and equipment (better access), a redesign (positive pressure) of air flow, and a modification (eliminating condensation inside equipment) of product cooling; enhanced (put science into procedures) the cleaning program; restricted wet cleaning; educated employees; and modified sampling protocols. A primary Salmonella control area was established within the plant to better manage an ongoing risk.

Sweeping moves filth around; worse is the use of compressed air. A better tactic for dry cleaning is vacuuming. Why are trailers that are being prepped for loading not vacuumed? Why are hard-to-reach areas air blown? Sweeping and compressed air may be acceptable if followed with vacuuming. Suction gathers deleterious material—some seen and some not seen. Auditor's Soapbox

Lessons Learned. What are lessons learned from this incident? There are numerous lessons, just a few of which are:

• the handling of the FDA investigation. Respect for investigative duty, trusting yet verifying, guided a cooperative discovery to a hidden problem.
• the use of a specialized multi-disciplined task force that was given authority to act while using sound science to fix the problem. Using the disciplines of engineering, maintenance, microbiology, sanitation, and R&D, top management facilitated by a project manager can solve many food plant problems. If the expertise is not available within the company, obtain expertise outside the company to fill in any experience/knowledge gaps.
• the concept of a primary “contaminant” control area. This is a powerful design attribute that can be used in the food industry. Define the “contaminant” to whatever you want it to be. A notable company in the flour milling industry uses this concept to control foreign material with a final sifter, entoleter, and metal detector, along with a thorough cleaning/inspection of containers prior to loading.
• the extending of a QA system to include checks and balances of testing procedures. There are times where an audit checklist isn’t enough.

Conclusion. This incident impacted an industry beyond one plant and one company. Although practical QA solutions were strategic to one company and one industry, solutions spread to other food-related industries. Good sanitary design is not to be underestimated. Designing a building for your process is much better than designing a process for your building. Proactively designing food safety into a plant is much better—and more economical—than doing it retroactively.

Are you prepared for an early morning regulatory investigation? Planning, preparation and practice will prevent a pitiful performance.