The best-laid plans of mice and men often go awry. This can be the case for even the most experienced processor when lethality or stabilization critical control points are not met. The deviations caused by this failure to meet CCPs can range in severity but will undoubtedly result in a recall if product is passed into commerce before the deviation can be addressed. By learning not only how to limit the number of deviations, but also by preparing for one if it occurs, processors are more able to respond to the threats caused by these deviations.

The most common deviations described here are those that fail to meet the lethality or stabilization parameters outlined by the FSIS Guideline of Appendix A and B. Although these parameters may vary for different products, the overall intent of these guidelines is to limit the number of bacteria growing within a product. When cooked and cooled properly, a product will contain less than 1 log₁₀ colony forming units (CFU) of potentially pathogenic bacteria. For example, the cooling guidelines of Appendix B, also called the Stabilization Guideline, aim to limit the germination of any Clostridium spores that might have survived the cooking process. For this reason, Appendix B has strict time limits for temperature ranges, ensuring that a product will cool faster than the time it takes for bacteria to become dangerous. When a product is cooled more slowly than Appendix B allows, the likelihood of bacterial growth and toxin production increases, and a deviation has occurred.

The occurrence of a deviation from Appendix A is less cut-and-dried. Although the guideline warns against cooking a product between the temperatures of 50° and 130° Fahrenheit for longer than 6 hours, it does not expressly prohibit it. This warning is grounded in the scientific evidence that exposing a bacterium, such as Staphylococcus aureus, to high temperatures for extended periods of time will cause that organism to become heat resistant. This heat resistance will increase the chances that the bacteria will survive lethal temperatures and go on to infect humans. Unlike other deviations, a product that contains heat-resistant bacteria will not benefit from being recooked and will most likely need to be discarded. Without clear time limits on rising cook temperatures, FSIS’s Appendix A has left producers to wonder exactly “How long is too long?’

If a processor suspects a deviation in either a lethality or stabilization critical control point, it is important to then assess how dangerous the deviation might have been. Although there are a number of tools that will assist in predicting bacterial growth, the USDA Agricultural Research Service supplies an online predictive software called the Pathogen Modeling Program (PMP) to help producers analyze the risk involved with a deviation. Through input of the times, temperatures, and other factors associated with the product, PMP can determine the amount of bacteria that was predicted to have grown under the specific parameters of the deviated product.

At predicted bacterial levels above 1 log₁₀ CFU, a product is prohibited from entering commerce. At these levels, a product might still be able to be recooked to lethal temperatures, as long as toxin production in those bacteria is unlikely. Bacteria that form toxins often do not do so until at least 6 log₁₀ CFU is grown, after which recooking will not destroy the toxin. Through the analysis of the deviated product, producers can best determine how to proceed, whether that is recooking the product, throwing it away, or sending samples to a lab for further analysis.

The most efficient way to decrease risk caused by deviations is to limit the chance of having a deviation in the first place. This can be done in a number of ways, and often simply involves following the practices outlined in a facility’s HACCP and SSOP plans. For example, by decreasing bacterial loads using safe handling practices on both raw product and food contact surfaces, producers are able to minimize the amount of bacteria on a product when it is cooked, resulting in a higher chance that all bacteria will be destroyed.

In addition, many deviations result simply from equipment failure. By keeping equipment such as smokehouses and temperature probes up to date and well maintained, the chance that a system malfunction will occur and cause a deviation is lowered.

One of the most integral parts of a well-run business is the ability to train staff to be aware of the challenges facing a facility. If operators are aware of the limitations posed by Appendix A and B, they are more likely to keep production consistent and spot deviations in time to decrease the harm caused. These, along with many other ways to reduce the number of deviations, have helped to make producers more aware of the threats faced when a lethality or stabilization CCP fails to be met.