The list is in order of weight
In the US, ingredients are listed “in descending order of predominance by weight.”1 The EU rule is the same: “in descending order of weight, as recorded at the time of their use in the manufacture of the food.”2
So the first ingredient is the one there’s most of, and the last is the one there’s least of. When you’re comparing two similar products, start with the first few lines.
One ingredient can be split across the list
Each ingredient takes its own place in that order. A product sweetened with sugar, glucose syrup and honey lists all three separately, and each one weighs less than the three together would. So each sits further down the list than a single sugar would have.
It’s worth reading to the end before deciding how far down something is. Here are the names sugar goes by.
Additives are named by what they do
In the EU, additives in categories such as colors, preservatives and emulsifiers “must be designated by the name of that category, followed by their specific name or, if appropriate, E number.”2 So a European label says what an additive is for, then gives its name or its number, as in “preservative: E211.”
Look up an E number on a label.
Allergens are marked, and the style depends on where it’s sold
A US label names the source of a major allergen in one of two ways: in parentheses after the ingredient, as in “whey (milk)” or “flour (wheat),” or in a line right after the list, such as “Contains wheat, milk, and soy.”3
An EU label does it inside the list itself. The allergen has to be “emphasised through a typeset that clearly distinguishes it from the rest of the list of ingredients, for example by means of the font, style or background colour.”2 You’ll usually see it in bold.
The two don’t cover the same allergens, either. The US names 9 and the EU names 14. Here’s how they compare.
“May contain” is voluntary
Lines like “may contain nuts” or “made in a facility that also handles nuts” are about cross-contact, not about the recipe. In the US, the FDA says these statements “are not required by law.”3
That cuts both ways. A product without one isn’t promising anything. If an allergy is serious, no warning isn’t the same as a guarantee.
The language follows the shop, not the factory
EU law requires the mandatory information to appear “in a language easily understood by the consumers of the Member States where a food is marketed.”2 That’s why imported food in Europe often has a translated sticker on it.
Shop abroad, or in an import aisle at home, and you can easily be holding a list in a language you don’t read at all.