Food safety problems often begin when perishable prepared foods remain at room temperature for too long. Bacteria can multiply rapidly under favorable conditions, and foods containing cooked meat, eggs, dairy, or other perishable ingredients require careful handling. This is why dishes such as chicken salad, potato salad, and coleslaw shouldn’t be left sitting for hours simply because they contain mayonnaise. As a general food-safety rule, perishable foods should be refrigerated within about two hours, or one hour when temperatures are above 90°F (32°C).

Another concern is cross-contamination. Imagine spreading mayonnaise onto raw-meat preparation surfaces or using a contaminated utensil and then returning it to the jar. Bacteria from other foods could be transferred in the process. Using clean spoons and knives, washing hands and preparation surfaces, and avoiding contact between ready-to-eat foods and raw meat can significantly reduce this risk.

Storage also matters. Commercial mayonnaise should be handled according to the label and refrigerated after opening when instructed. More importantly, mayonnaise-based prepared dishes should remain properly chilled until they’re served. At outdoor gatherings, keeping bowls over ice or returning food to a refrigerator or cooler promptly can help maintain safer temperatures. When you’re uncertain how long a perishable dish has been sitting out, the safer choice is to discard it rather than relying on its smell or appearance.

So why does mayonnaise receive so much blame? It’s frequently present in dishes traditionally served at picnics and barbecues, where refrigeration can be difficult. If someone becomes sick afterward, mayonnaise may seem like the obvious suspect. In reality, time, temperature, hygiene, and contamination are often the more important factors.

The takeaway is simple: mayonnaise itself isn’t automatically dangerous. Proper refrigeration, clean utensils, careful preparation, and sensible serving times help keep mayonnaise-based foods safer.

So next time you see potato salad at a picnic, don’t just watch the mayonnaise—watch the clock and temperature too.