Unintended ingredients

Food labeling laws require food allergens to be identified even in very small amounts — but only when they're contained as an ingredient. Manufacturers aren't required to include warnings about food allergens accidentally introduced during manufacturing or packaging (cross-contamination). This potentially can cause trouble if you're very sensitive to food allergens.

Many manufacturers voluntarily include warnings, but these advisory labels aren't always clear. And, manufacturers have different ways of saying a food allergen may be present. For example, labels may say "manufactured in a factory that also processes wheat" or "may contain soy."

The FDA is working to make the format of these advisory labels more consistent so that it's easier to identify which products contain allergens. When in doubt about whether a product contains something you're allergic to, it's best to avoid it until you check with your doctor.