Will I have an allergic reaction to peanut oil if I have a peanut allergy?

This question causes a lot of confusion because not all peanut oils are the same. Peanut oil can be refined, unrefined or a mixture of both.

Refined peanut oil

Refined peanut oil has been processed in a way that removes the peanut proteins from the oil. It is the proteins that cause allergic reactions. Studies have shown that refined peanut oil will not cause allergic reactions for most people who are allergic to peanuts. If you do have a reaction, it’s likely to be very mild.

Unrefined peanut oil

If an oil is unrefined (sometimes known as crude oil) this means the allergenic proteins are still present, as it hasn’t been processed in a way that removes them. Unrefined peanut oil is more likely to cause an allergic reaction because it still contains allergenic proteins.

Does this mean refined peanut oil is completely safe for people with peanut allergy?

The biggest study that tried to find out whether refined peanut oil is safe took place in 1997 in Southampton. 60 adults with peanut allergy were given refined peanut oil and then unrefined peanut oil. None had allergic reactions to the refined peanut oil and six had mild allergic reactions to the unrefined peanut oil. The way peanut oil is refined has not changed since the 1990s so there’s no reason to think that these results are not still valid.

It would be impossible to find out whether refined peanut oil is 100% safe because it would mean testing everybody with a peanut allergy. The sample of 60 people in the Southampton study is enough to confidently say that refined peanut oil is likely to be safe for most people with peanut allergy. A more recent study also confirmed that it’s very unlikely that refined peanut oil could cause a reaction even if you have experienced serious allergic reactions to small amounts of peanut in the past.

Most allergy experts also agree that refined peanut oil is very unlikely to cause allergic reactions. But it is up to you as an individual with peanut allergy, or as parents or guardians of a young child with peanut allergy, to weigh up the evidence and decide if you want to include it in your diet or avoid it.

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Where is refined oil used?

Refined peanut oil is much more expensive than other similar refined oils such as rapeseed, soya or sunflower oils. This means it’s not typically used in processed food products like biscuits, cakes, crisps and ready meals in the UK.

Refined peanut oil does have some special properties. It’s very stable and can be heated for longer than other oils at high temperatures so it’s used by some fish and chip shops and specialty burger chains.

Refined peanut oil is sold in bottles as peanut oil or groundnut oil.

It’s also used in some cosmetics and pharmaceutical products.

Where is unrefined peanut oil used?

Unrefined peanut oil is not usually used at all in pre-packed foods in the UK. It is sold in bottles as ‘filtered’ or ‘cold-pressed’ peanut oil or groundnut oil.

  • Filtered means the oil has been passed through a fine mesh to remove any solid particles or contaminants but has not been through the refining process.
  • Cold pressed means the oil has been extracted from the peanuts using a mechanical pressing process but has not been through the refining process.


Unrefined peanut oil may be used in multicultural restaurants, for example Indian, Thai or Chinese. It’s often used to give dishes a peanut flavour. It is sometimes blended with refined oil for its flavour.

Unrefined peanut oil is not used in pharmaceutical products.

Are there differing degrees of oil refinement?

The European association for the oilseed industry (known as FEDIOL) has agreed a refining standard. This means all refined peanut oil is processed in the same way, going through special stages called degumming, neutralising, bleaching, filtration and deodorisation. There is no such thing as “partially” or “less” refined peanut oil – it will either be refined, unrefined or a mixture of the two.

Do all types of peanut oil have to be declared on food labels?

All peanuts and products made from peanuts are included in the list of top 14 major food allergens in the UK. This means they must be highlighted on ingredients labels, in bold for example.

Even though the evidence tells us there is very little risk from refined peanut oil, the law still requires that it is listed and emphasised, in bold for example, on ingredients labels.

It may not always be obvious from the label of bottled peanut oil whether it’s refined or unrefined.  If in doubt, always check with the manufacturer.

What are the risks in restaurants?

Restaurants, cafes, hotels, takeaways and other catering businesses are required by law to provide information on major allergens, including all types of peanut oil.

Refined peanut oil is unlikely to cause a reaction. Check with the staff whether the food you would like to choose contains peanut oil and whether it has been refined. If you are left in any doubt, it is best to choose a different meal.

If the chef uses refined peanut oil that they have already used to fry a product containing nuts such as peanut cutlets or spring rolls, the oil might be contaminated with peanut proteins and may not be safe for you. You can ask in the restaurant if the oil is used more than once and there may be a risk of cross-contamination.

Is refined peanut oil used in cosmetics and medications?

Because it’s stable, refined peanut oil is often used as a base in pharmaceutical products. It’s labelled with its Latin name, Arachis oil. Products can include:

  • vitamins
  • ear drops
  • nappy rash creams
  • sun creams
  • eye pencils.

Will peanut oil (arachis oil) in cosmetic or pharmaceutical products cause allergic reactions?

There have not been any good quality studies to answer this question. Pharmaceutical and cosmetic grade refined arachis oil is highly purified so the evidence would suggest it is unlikely to pose any risk. But because this is not certain, you might prefer to avoid these products if you have a peanut allergy.

Does peanut oil in skin creams trigger allergies in children?

Some allergy experts think there may be a link between eczema or nappy creams that contain peanut oil and the development of peanut allergy in some young children. This may be because tiny amounts of peanut protein are present – not enough to cause allergic reactions but enough, in some cases, to “set up” an allergy to peanuts if the cream is put on broken skin (to soothe eczema or nappy rash for example).

There is no evidence that this does happen, but if you have allergies in your family you might prefer to avoid using creams containing peanut oil on babies and young children just in case.

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