The bigger risk usually comes from the foods mixed with mayonnaise, including chicken, eggs, potatoes, seafood, and dairy-based ingredients. If these dishes are left at room temperature for too long, bacteria can multiply rapidly, especially during warm weather.
Cross-contamination can also create problems. Using contaminated utensils, returning used spoons to the jar, or leaving opened mayonnaise and prepared salads unrefrigerated for long periods can increase the risk of illness. Proper refrigeration and clean handling are therefore essential.
In most cases, mayonnaise itself is not the main danger. Poor temperature control, contaminated ingredients, and unsafe food handling are much more likely to cause foodborne illness. Keeping cold foods chilled, using clean utensils, and refrigerating leftovers promptly can greatly reduce the risk.
