Model Inaccuracies & Limitations

This calculator provides a simplified estimate of bacterial growth. For the sake of transparency, it's important to understand its limitations:

• Immediate Growth: This model assumes bacteria start multiplying the moment conditions are right. In reality, bacteria usually go through an "adjustment period" called a lag phase before they begin growing. This means the model's timeline for risk might be a bit faster than what actually happens.
• No Upper Limits: The graph shows bacterial numbers that could theoretically grow forever. Realistically, bacteria stop multiplying when they run out of food and space, hitting a ceiling. This model doesn't show that ceiling, so the extremely high numbers are just theoretical projections.
• A "General" Bacteria Profile: This tool uses a single, average profile for "bacteria." It doesn't distinguish between specific types like Salmonella or Listeria, which behave very differently. For instance, some can grow in the cold and some are much tougher, so this model represents a general case.
• Underestimates Cooking: The model slightly reduces the starting number of bacteria for cooked food. In reality, proper cooking is extremely effective and eliminates almost all starting bacteria. The risk for cooked food usually comes from re-contamination after it's been cooked.
• Factors Are Treated Separately: The model looks at things like acidity and saltiness one by one. In the real world, they work as a team—a concept called "hurdle technology"—where having a little salt and a little acid together is much more powerful at stopping bacteria than the model might show.
• Shows a Count, Not a Personal Risk: The "Danger Zone" simply shows when the estimated number of bacteria gets high. It doesn't—and can't—calculate the actual probability of a specific person getting sick. That real-world risk depends on many other factors, including your personal health, your age, and the exact type of bacteria present.