Does “may contain nuts” include peanuts?

When is a nut not a nut? When it’s a peanut. Unless it’s on a “may contain” label, in which case it might be…

The difference between peanuts and tree nuts

One of the first things you learn when entering the nut allergy world is that there’s a difference between peanuts and tree nuts. In fact, it was the taxi driver taking me to visit my son in hospital who turned out to be The Knowledge on allergies and taught me the distinction.

Peanuts (aka groundnuts) are legumes, botanically related to foods like peas, beans and lentils. Whereas tree nuts include almonds, hazelnuts, walnuts and so on. A person can be allergic to peanuts, tree nuts or both.

At the moment, my son’s only known food allergy is to peanut. Our doctor’s advice is to avoid all nuts. However, some people only avoid their specific allergens, meaning, for example, some purely peanut allergic people eat tree nuts (and vice versa).

Peanuts and tree nuts must be distinguished on an ingredients label

In the UK, food allergen labelling law requires the label to state if a prepacked food or alcoholic drink contains one of the top 14 food allergens (or an ingredient made from them). From December, the way in which ingredients are displayed will change, so that the allergens must be highlighted (for example, in bold). The obligation to provide details of allergens will also be extended to foods sold loose and when eating out.

Under both the current law and the law from December 2014, the list of 14 allergens distinguishes between:

  • Peanuts, and
  • Certain nuts (i.e. almonds, hazelnuts, walnuts, cashews, pecan nuts, Brazil nuts, pistachio nuts, macadamia nuts and Queensland nuts).

A bag of peanuts and cashews should state “peanut” and “cashew nut” separately in the ingredients list. The manufacturer couldn’t simply put “Ingredients: nuts”, as this would certainly not cover peanuts.

Could the manufacturer put “Ingredients: peanuts and nuts”? It seems not. I asked the Food Standards Agency (FSA) whether a food company also has to name the specific type of tree nut. They advised that:

“a product containing tree nuts such as Walnuts, Brazil nuts, Almonds etc, as ingredients would by law have to make a clear reference to these particular nuts on the label.”

“May contain nuts” warnings

Under section 15 of the Food Safety Act 1990 it is an offence to sell food which is falsely described or labelled in a way which is likely to mislead as to its nature, substance or quality. However, the specific allergen labelling rules (including the requirement to differentiate between peanuts and other nuts) only apply to intentionally added ingredients and do not cover accidental cross contamination during the manufacturing process. (For more information, see Deciphering UK food allergen labelling law.)

The use of precautionary labels (“may contain nuts”, “not suitable for nut allergy sufferers”, “produced in a factory that also processes nuts” etc) is voluntary. Whilst the FSA has issued best practice guidance and the label cannot mislead as to the food’s nature/substance/quality, there is no legal duty to use a “may contain” label, nevermind a specific form of may contain wording. So, if a product is at risk of cross contamination from almonds, there is no obligation to state “may contain nuts”. Ditto if a peanut product is made on the same line: there is no duty to put “may contain peanut” on the packaging. In addition, the obligation to distinguish “peanut” from tree nuts applies to intentional ingredients.

Suppose a food company produces a biscuit which does not contain peanut or any tree nuts in the ingredients. The food company assesses the manufacturing process and decides there is a demonstrable and significant risk of cross contamination from both peanut and walnut. They could decide not to use any  precautionary label whatsoever. However, suppose they do decide to use a “may contain”, could they state:

  1. May contain peanut and walnut
  2. May contain peanut and nuts
  3. May contain nuts
  4. May contain peanut, or
  5. May contain walnut?

I asked the FSA whether “may contain nuts” could encompass peanut too and they confirmed:

“General statement such as “May contain nuts” will generally refer to both peanuts and tree nuts…”

Therefore, the company would be within their rights to use options 1, 2 or 3.

I don’t know whether 4 and 5 would be acceptable. Can a company pick and choose its may contains? Or does stating “may contain walnut” imply there isn’t a cross contamination risk from, for example, peanut?

Which companies bracket peanuts with nuts?

To me, it feels like a specific reference to peanut in a may contain warning is relatively unusual. Mars bars and Kelloggs Frosties spring to mind. However, the phrase is nowhere near as common as “may contain nuts”. Perhaps that’s because the cross contamination risk from peanut is rare compared to all the other tree nuts. Or perhaps the tendency is for manufacturers to lump peanuts and tree nuts together as “nuts” for may contains.

In practice, how many companies specify “may contain peanut” and how many use “may contain nuts” to mean both peanut and tree nuts? And for those who have some products stating “may contain peanut”, do they ALWAYS differentiate, or might some products in their range state “may contain nuts”?

It’s yet another may contain conundrum and one that is deeply unhelpful for those people only avoiding certain types of nuts. How frustrating if you are only avoiding peanut, to have to steer clear of products labelled “may contain nuts” potentially unnecessarily. And by specifying peanut or the type of tree nut in the “may contain” label, food companies would be reaching a wider customer base. reported last week how the “Nut Allergy Ecosystem” survey carried out by Rich Products showed how one child’s nut allergy impacts the shopping habits of a wide circle of people, including the child’s family, friends, classmates, teachers etc. The article pointed out that nut free labels are therefore a “missed business opportunity”. It seems to me the same is true for specific may contain details.

If anyone has information on those brands which differentiate between peanuts and other nuts in their precautionary labels, please do post a comment below – I would love to hear from you. I do plan to contact the leading supermarkets to see whether they specifically refer to peanut in their advisory labels – update to follow when I receive the replies.


  1. OK. I have a confession, I was of the opinion that restricting the diet to exclude all the ‘may contain nuts’ foods was excessive. After all, our allergy nurse advised to ignore these labels. But then my son had a reaction to a bag of fruit jelly sweets which came with a nut warning. His face was so swelled up that he looked like he’d been in a boxing ring.

    It’s still not quite clear-cut as there’s a chance he is developing a fruit allergy – he once had a lip swell up after eating an orange and this week complained of a sore lip after eating completely nut free fruity stars. Still with a diagnosed nut allergy, I’m not taking a chance on may contain labels unless it’s something he has eaten many times.

    1. Hi Karen, Thanks for the message. We started off ignoring “may contain nuts” labels too – our hospital said the same as yours. My thinking on it changed though, when I started hearing stories from other mums about reactions to foods labelled may contain. Hope you are able to get to the bottom of your son’s reactions, it’s maddening when you don’t know the cause of something. Louise

  2. Just a little comment for Karen who said that she would only now allow her son to eat foods labelled ‘may contain’ that he has eaten many times before – this is not the point! ‘May contain’ means there is a chance of cross contamination in the factory process, so if he has eaten it 100 times, it may be the 101st one he eats that is contaminated! It doesn’t mean that food is safe.

  3. Hello
    Great article. My daughter has a peanut only allergy and I was wondering whether ‘may contain nuts included peanuts’ as they are not technically nuts, so you’ve cleared that up. We are finding it really frustrating as many manufacturers seem to be labelling everything may contain nuts, Sainsbury’s is particularly keen on this, even the make your own pizzas may contain nuts. As far as I can tell Lindt chocolate are specific with labelling.
    I’d be really interested in your responses from the Supermarkets. Good luck!

    1. Just a comment for Michala above. I have a peanut only allergic son and we actually find Sainsburys particularly great at labelling. The allergy section of their website states which foods are suitable for people with peanut allergies. Sainsburys branded foods do distinguish between nuts and peanuts. I was so thrilled to find that my son was able to eat many of their cakes and wrapped baked items. I will buy ‘may contain nut products’ for him, but it has to be a Sainsburys branded product. If it states that it ‘may contain nuts and peanuts’, then I won’t buy it. The pizza section and fresh bakery section is still out of bounds unfortunately. Hope that this helps.

  4. Cadbury operate in a similar fashion to Sainsburys. eg for Cadbury’s Boost bars the allergy warning states: May Contain: Peanuts, Soya, but on the majority of their other products the warning is: May Contain Nuts. I have contacted Cadbury a couple of times to confirm this does mean what it appears to mean (!) and have had a positive reply both times. Another retailer who uses the same system (for their own branded products, obviously) is Iceland.
    If only the English language hadn’t decided to have the word ‘nut’ incorporated in the word ‘peanut’ and we had called them peabeans or something, life would be a lot easier! Sarah (mum to peanut allergic son)

  5. Be wary of M&S. They separate out peanuts on some “may contain” labels, but their general rule is to lump peanuts in with nuts. As a result you are lulled into a false sense of security.
    However, after querying (as I saw peanuts listed in the French language version in their labels), it appears that France and Netherlands are more strict about this. As a result, if they translate to other languages look at the French version. The word you need to look out for is “arachide” or “cacahuete”.

  6. Further to the above. I’ve contacted Kipling and Fox’s about their allergen labelling. I never heard back from Fox’s, but Kipling confirmed that they are strict about not classing peanuts as nuts.

  7. I have found D&D Chocolates very good, having spoken to them, their chocolate easter eggs are produced in a nut free environment – also dairy, gluten and soya free – so perfect for my lo who is allergic to seemingly everything…

  8. In case this helps anyone, I had confirmation today that the co-op’s policy on labelling their own brand products is that they will specify peanut both in ingredient lists and may contain warnings. If something has no peanuts in the ingredients but has a warning saying ‘may contain nuts’, this will mean tree nuts only. In other words, they will treat peanuts separately in their ‘may contain’ warnings.

    Also, further to the Cadbury comment above, the umbrella company Mondelez sticks to those rules so other products made by Mondelez should also be ok.

    Finally, Thorntons also told me that they will always label peanuts separately in their ‘may contain’ warnings too.

  9. Forgot one: I had this reply from Nestle:

    To clarify new legislation regarding Peanuts & other Nuts: where Peanuts are not directly added to the product as an ingredient they will always be declared separately in a trace warning on pack, they are no longer grouped together with other nuts.

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