Neither word is a regulated claim, in the US or the EU
This is the fact that makes both words slipperier than they look. In its 2024 draft guidance on labeling plant-based alternatives, the FDA states it directly: While FDA regulations do not currently define vegetarian or vegan, the term vegetarian is commonly used on food labels to communicate the food does not contain ingredients from meat, fish, or poultry but may contain dairy or eggs, and vegan is commonly used to communicate that the food does not contain any animal derived products. The agency is working from common usage, not a rule. Its separate 2023 draft guidance on plant-based milk goes further on the other word: plant-based milk is not the common or usual name of plant-based milk alternatives, meaning plant-based itself has no formal status even as a category name, only as a description.
The EU tells the same story from a different angle. The Food Information to Consumers Regulation (EU No 1169/2011) says in Article 36(3) that the Commission shall adopt implementing acts covering information related to suitability of a food for vegetarians or vegans. That instruction dates to 2011. The current consolidated text of the regulation still carries it as an open, unfulfilled mandate, and no such implementing act has been adopted at EU level, so vegan and vegetarian remain undefined in EU law too.
| Term | Defined by regulation? | What's true instead |
|---|---|---|
| "Vegan" (US) | No | FDA treats it as a common-usage term; usable if truthful and non-misleading, with no rule setting its boundaries |
| "Plant-based milk" (US) | No | FDA's own guidance says this is not a common or usual name, just a description |
| "Vegan" / "vegetarian" (EU) | No | The Commission has been directed to write rules on this since 2011 and hasn't |
| "Milk" (EU) | Yes | Reserved by law for mammary secretion; plant products can't legally be called milk |
| "Organic" (US and EU) | Yes | Backed by an actual certified standard and inspection regime, unlike either word above |
What the absence of a definition means at the shelf
No regulator pre-approves a plant-based or vegan claim before it reaches a shelf in the US or the EU. Both words are policed the same way as any other label claim: after the fact, and only if it's false or misleading under general consumer-protection law. That's a real backstop, but it's a much lower bar than a defined standard with its own inspection regime. It means the word plant-based describes composition loosely and carries no formal promise about trace ingredients, and it means vegan, while a stronger everyday claim, still isn't independently verified by a regulator before the product ships. This is exactly the gap that certification schemes were built to fill, each with its own published standard and its own scope.
One thing the EU actually has defined: what can be called milk
The EU's agricultural market regulation (EU No 1308/2013) states that milk means exclusively the normal mammary secretion obtained from one or more milkings, and that this designation may not be used for any product other than those referred to in that point, with only narrow exceptions for products whose plant nature is already clear from traditional usage. That is why oat and soy drinks in EU supermarkets are labeled drink rather than milk, while the same products in the US routinely say milk on the front of the pack. The US took the opposite approach: FDA's draft guidance recommends against calling a product plant-based milk alone, but doesn't stop soy milk or oat milk from using milk once qualified by the plant source. Same ingredient, two different legal environments, two different words on the carton.