Despite federal legislation passed 15 years ago, food labels don’t always alert consumers to allergens that may be present in packaged goods. When you’re shopping for someone who has a food allergy, a trip to the grocery store is like a police investigation. Each product must be scrutinized. Labels are examined, each ingredient studied. My 5-year-old son, Alexander, is allergic to almonds and hazelnuts, so my wife and I spend a lot of time trying to decipher food labels. If you miss something, even one word, you risk an allergic reaction. Although federal law requires manufacturers to include allergen warnings on prepackaged foods, it’s not always clear which products contain allergens and which do not. The regulation doesn’t cover all types of foods, nor instances in which trace amounts of allergens may be present. This has created a confusing and risky marketplace for my family and millions of others — roughly 8 percent of children have a food allergy. I set out to better understand allergen labeling and the problems consumers face. Here’s what I learned. Congress passed the Food Allergen Labeling and Consumer Protection Act in 2004, a rule book for manufacturers. Companies mu...