Peanut allergy: hidden peanuts, groundnut oil, and how restaurants keep guests safe
By the Menulta editorial team · Facts checked 15 October 2026 · Updated 15 October 2026
The short answer
A peanut allergy is an immune reaction to proteins in peanuts. It is one of the food allergies most often linked to severe reactions and anaphylaxis, and it usually lasts for life. Peanuts are legumes, not tree nuts, so they are a separate allergen in EU law. Peanuts hide in satay and other sauces, curries, desserts and groundnut oil, and trace amounts from shared equipment can be enough to trigger a reaction.
Peanuts are not nuts
Botanically, peanuts are legumes, related to peas, beans, soy and lupin. Tree nuts, such as almonds, walnuts and cashews, grow on trees. Annex II of Regulation (EU) 1169/2011 lists peanuts and nuts as separate entries, and a menu should declare them separately.
Some people are allergic to both peanuts and tree nuts, and some to only one. Never answer 'it's nut-free' to a peanut question, or 'no peanuts' to a tree nut question. Check the specific allergen.
Because peanuts are legumes, some peanut-allergic people also react to lupin, another legume used in some flours and breads in Europe. Lupin is its own Annex II allergen, which is one reason it was added to the list.
Names that mean peanut
- Peanut, groundnut, monkey nut, goober
- Arachis oil, groundnut oil, peanut oil
- Peanut butter, peanut flour, peanut protein
- Satay, gado-gado and many West African groundnut stews
- Some 'mixed nuts', praline and nougat
Peanut oil in restaurant kitchens
Annex II gives no exemption for peanut oil, unlike fully refined soybean oil. Groundnut oil must therefore be declared as peanut when it is used, whether it is refined or not. Some highly refined peanut oils contain very little protein, but whether a particular guest can tolerate them is a decision for the guest and their doctor, not the kitchen.
Groundnut oil is popular for frying because of its high smoke point. If your fryer uses it, every fried item is a peanut-containing dish for the allergen record. Check the oil specification, especially when a supplier substitutes a different blend.
Where peanuts hide in restaurant dishes
| Dish or component | Possible peanut source |
|---|---|
| Asian dishes | Satay sauce, pad thai garnish, peanut oil, crushed peanuts in salads |
| Curries and stews | Peanut butter or ground peanuts as a thickener |
| Desserts | Praline, brittle, some brownies, bought-in biscuits and cereal bars |
| Sauces and dressings | Peanut butter in dressings, some chilli sauces |
| Fried food | Groundnut oil in the fryer |
| Bar snacks | Bowls of peanuts and mixed nuts that shed dust and crumbs |
| Vegetarian dishes | Peanut-based burgers or peanut protein |
Cross-contact: why traces matter
For many peanut-allergic people, the amount needed to cause a reaction is very small. Shared utensils, a chopping board used for a peanut garnish, a wok not cleaned between dishes, or crumbs from a bar snack bowl can all transfer enough peanut protein.
Effective controls are simple but must be consistent. Clean surfaces and utensils with hot soapy water before preparing a peanut-free dish, since wiping alone moves protein around rather than removing it. Use separate utensils, keep peanut garnishes away from the pass, and add garnishes last at a separate station. If you cannot prevent cross-contact for a particular dish, tell the guest.
Recognising a serious reaction
Staff do not need medical training to save a life, but they should know the warning signs of anaphylaxis: difficulty breathing or swallowing, swelling of the tongue or throat, a hoarse voice, wheezing, dizziness or collapse. The response is to call the emergency number immediately (112 in the EU), help the guest use their adrenaline auto-injector if they have one, and keep them lying down with legs raised, or sitting up if breathing is difficult. Never send someone with these symptoms outside or to the bathroom alone.
Questions to ask your suppliers about peanuts
Peanut exposure in restaurants often comes from bought-in products rather than from the kitchen's own cooking. Ask your suppliers which frying and cooking oils contain groundnut oil, including blends sold as 'vegetable oil'. Ask whether desserts, biscuits, cereal bars, sauces and curry pastes contain peanuts or are made on lines that handle them. Ask whether bread and pastry suppliers use peanuts anywhere in their bakery.
Record the answers with your allergen record and repeat the check when a product is substituted. A replacement curry paste or dessert from a different brand is one of the most common routes for undeclared peanut onto a plate.
Sources
This guide is general information, not medical or legal advice. Guests with an allergy should follow their doctor's advice. Operators should confirm their own setup with their food safety adviser or local authority.