Peanuts

What a peanut allergy is

A peanut allergy is a reaction to the proteins in Arachis hypogaea — a plant that is not a nut at all. Peanuts are legumes. They flower above ground and ripen underground, in the same family as peas, beans and lentils. That botanical detail sounds academic until you are holding a packet, because it decides which word the label uses and which “free-from” claim covers you. A pack that says nut free is usually talking about almonds, cashews and walnuts; a pack that says peanut free says nothing whatsoever about those. Neither claim is defined in law the way the ingredient list is.

Peanut also turns up in aisles where nobody is looking for it. Satay and groundnut sauces, mole and some chilli pastes, cereal and protein bars, biscuits, ice cream, vegetarian mince and meat substitutes, marzipan substitutes, samosas and spring-roll fillings, and defatted peanut flour used purely as a protein booster or thickener. The ingredient list is the only place any of this is settled.

The names that do not say “peanut”

Groundnut is the ordinary word for peanut across British, Indian and much of African English. Groundnut oil is peanut oil; groundnut stew is a peanut stew. On imported snacks and curry pastes this is the word you will actually see.

Arachis hypogaea, and arachis oil, are the botanical name. Cosmetic and pharmacy labelling uses Latin names by convention, so arachis is what appears on ointments, bath oils, vitamin capsules and some medicines rather than the word peanut.

Monkey nut means a whole peanut still in its shell. It shows up on market and bulk-bin labels and on bird food, which is worth knowing if peanut dust in the house is a problem.

Mandelonas are peanuts that have been de-flavoured and soaked in almond flavouring, then sold as a cheaper almond substitute. This is the alias that catches people out most, because it is sitting in exactly the place you would expect a tree nut.

Beer nuts are coated, roasted peanuts sold as a bar snack — the word peanut is not guaranteed to appear next to it.

Earth nuts is a literal translation of names like the German Erdnuss, and appears on packaging that has been translated into English by the exporter.

Goober and goober peas are older southern-US names, still used on some confectionery and regional products.

Hydrolysed plant protein names no plant. Peanut is one of the sources used for it. Until the manufacturer says which plant, this is not information — it is an open question.

How the label is worded where you are

In the EU and UK, peanut is on the list of allergens that must be picked out of the ingredient list so that it stands out from the rest, normally in bold. That emphasis is the thing to scan for, and the rule reaches the aliases by forcing the peanut origin to be named: a food sold in the EU or UK says peanut oil, emphasised, not arachis oil. Arachis survives on medicines and cosmetics, which are governed by separate labelling rules and carry no emphasis duty at all — nothing there is bolded. In the United States the requirement works differently — the label has to use the plain word peanut, either inside the ingredient list or in a “Contains” line below it, so casein-style technical names cannot hide the allergen.

Outside those systems, plenty of countries have no emphasis rule and no Contains line. The word sits in the middle of the list, in the local language, in the same weight as everything else.

Cross-contamination and “may contain”

Precautionary wording — “may contain traces of peanut”, “made in a factory that also handles peanuts”, “not suitable for peanut allergy sufferers” — is voluntary almost everywhere and the phrasing is not standardised. There is no legal ladder in which one phrase is safer than another; the difference between them usually reflects the manufacturer’s legal team, not the production line. The other half of that is more uncomfortable: the absence of a warning is not evidence that no peanut came near the product. Loose bakery items, pick-and-mix, deli counters and refilled bulk bins carry no ingredient list at all.

PNut treats any precautionary wording as May contain rather than folding it into either a clean or a failed result. If you are trying to judge how seriously to take one of those lines, what “may contain traces” actually means is the longer answer.

Reading a peanut label abroad

Three things change at the border. The word changes — arachide, cacahuete, Erdnuss, 花生. The emphasis convention changes, so the bolding you are used to hunting for may not exist. And the script may change entirely, which makes visual scanning for a familiar shape useless. Translated stickers applied over the original label are common, and they are sometimes shorter than the list underneath them, so it is worth reading the original as well. The table below covers the words most likely to be on the pack, and reading a label in a language you don’t speak covers the method around it.

How PNut flags peanuts

Scan the barcode and PNut looks the product up and reads its published ingredient list; photograph the ingredient panel instead and it reads the text off the label, in any of 40+ languages. It checks for peanut and for every alias on this page, then returns one of four verdicts — Safe, Contains allergen, May contain, or Unknown when the label cannot be read. It says Unknown rather than guessing.