A popular healthy crisp snack sold at Asda, Ocado and Holland & Barratt has been urgently recalled over fears it could be dangerous to those with severe dairy allergies.

Food safety watchdogs stuck a 'do not eat' alert on batches of Boundless 'Sour Cream and Onion Flavour Chips', sold for as little as £1. 

It is feared the savoury snack may contain hidden traces of milk, which is not featured on the label and poses a risk to anyone with an allergy or intolerance to milk. 

The Food Standards Agency (FSA), which published the alert, issues recalls when problems are spotted with food that means it should not be sold. 

Boundless said the recall only affected its 80g packets of the crisp and four different batch codes. 

These included codes 31724 and 32424 with a best before date of November 30, 2025 and codes 34624 and 34724, with a best before date of December 31, 2025. 

The manufacturer added: 'The batch code and best before date can be found on the back of the pack in the bottom right corner. 

'If you have bought Boundless Sour Cream and Onion Flavour 80g Chips, do not eat them.

'Instead, return the product to the store for a full refund, with or without the receipt.

'For more information contact us on [email protected].' 

As well as supermarkets including Asda, the crisps are also sold online on health websites including Dolphin Fitness and Vitalife health. 

The FSA also said: 'Point of sale notices will be displayed in all retail stores that are selling this product. 

'These notices explain to customers why the product is being recalled and tell them what to do if they have bought the product.'

People who cannot consume milk are either allergic to the proteins in cow's milk or they cannot digest the sugar in the product, known as lactose intolerance.

Milk allergy symptoms can range from a rash, itching and swelling on the skin to vomiting, stomach cramps and diarrhoea that starts within minutes of eating or drinking items that contain dairy.

However, those who suffer from delayed cow's milk allergy may not have any symptoms until two days after exposure.

In severe cases, it can cause anaphylaxis — a severe, life-threatening reaction when swelling in the throat can block the airways.

A milk allergy can be diagnosed by a person’s immediate reaction to milk, as well as skin, blood and breath tests.

Around three in 100 babies have a cow's milk allergy but most grow out of it during their childhood.

Older children and adults who are allergic to cow's milk tend to have a more serious allergy.