“May contain” labelling: A short guide for consumers with food allergies

This is a short guide seeking to explain what is meant by precautionary allergen labelling (PAL) and why it is used, and help food allergic individuals understand PAL in order to remain safe when shopping for food and eating out.

Food allergens can be present in food products for two different reasons: they can be added intentionally as ingredients or processing aids or accidentally due to cross-contamination. When there is a risk of the unintentional presence of allergens in foods, precautionary allergen labelling may be used. Contamination from allergens can occur at any point in the food supply chain. It may occur during cultivation (growing in the fields), transport, preparation or manufacture. The risk resulting from different types of contamination can vary from no risk at all to harmful for consumers with food allergies and should be assessed by food manufacturers before using PAL. Precautionary allergen statements may also be used for foods sold loose, such as those in catering establishments (cafe, restaurants), markets and delicatessens, and bakery sections of supermarkets when food allergens are present.

Food businesses have a legal responsibility to ensure the food they provide is safe for all consumers, including those with particular dietary needs1. When removing or minimising the risk of cross-contamination with allergens is not possible, the food business may use a statement to warn consumers that the product carries a risk to those with food allergies. This warning can be found on the packaging of pre-packed foods or on a menu or other suitable location, if the food is sold loose. The wording of this warning may vary but is often known as “may contain” labelling, precautionary allergen labelling (PAL) advisory or alibi labelling.

For the purpose of this guide, we have used the term precautionary allergen labelling (PAL).


Is the use of PAL compulsory?

No. Many people believe the law requires "may contain" warnings, but this is not the case. There is no specific legal requirement under allergen labelling laws for food manufacturers, retailers or caterers to warn of possible risks of cross-contamination from allergens. A new regulation (EU No. 1169/2011)2 on the provision of food information to consumers, which became enforceable from 13 December 2014, includes the potential for PAL become a legal requirement, should an approach be agreed in the future. This regulation also includes the requirement that, where PAL is used, it must not mislead the consumer, it should not be ambiguous or confusing, and, where appropriate, should be based on relevant scientific data. As stated earlier, food safety laws still require that food sold to the final consumer should not be unsafe.

If a product has a warning, does it mean it is unsafe and should I avoid it?

→ Speak with your National Patient Support group if you would like help with what questions to ask.

Generally, if a product has a PAL warning, it should be taken seriously unless:

  • You have spoken with the food company concerned and decided that the risk is acceptable for you
  • Your doctor or allergy specialist has assessed you as being low risk for severe allergic reactions and advised that you may be able to tolerate certain low-risk products with PAL.

How do I know if I am at risk of a severe reaction?

Predicting those people who are at risk of severe allergic reactions is difficult and an assessment should be undertaken by a doctor who has received training in assessing allergic risk or by an allergy specialist. Some factors that may increase the risk of having a severe reaction include:

Age: Young adults in their teens or twenties are at greater risk. This may be partly because they take more risks but this age group does appear to be particularly vulnerable.

Dose: Despite a strongly held belief to the contrary, there is no strong evidence of a relationship between dose and severity but it is prudent to minimise dose, as other factors may be out of your control on any particular day (e.g. health).

Medication: If you are taking certain types of medication (e.g. non-steroidal anti-inflammatory drugs [NSAIDs], e.g. ibuprofen, or treatments for indigestion [proton pump inhibitors or PPIs]), you may be at greater risk.

Alcohol: Drinking alcohol may make risk taking more likely and, therefore, impair allergen avoidance as well as affect how well you respond to your symptoms. It may also increase the uptake of allergens from the gut, making a reaction quicker or more severe.

Exercise: Physical activity just before or after an allergic reaction can make it more severe or in some cases may trigger a reaction.

Health: If you are exposed to your allergen(s) when you have an infection or are generally unwell your reaction may be more severe; poorly controlled asthma is a risk factor for severe reactions; and individuals with heart disease or taking certain medicines might also be at greater risk (see above).

If any of these factors are present, you may be at greater risk of a severe reaction. Your allergy specialist or doctor may advise you about other factors that can affect your level of risk.

If you have been prescribed adrenaline auto-injectors (AAIs) you should ensure that you know how to use them. You should also carry these and any other emergency medication with you at all times without exception. If for some reason you do not have access to your AAIs, you should take extra care to avoid foods with PAL or eating at catering outlets where there is a significant risk of cross-contamination.

Some food allergic individuals can tolerate certain food allergens, such as egg or milk, or foods containing these allergens, if they have been well processed or cooked. Generally, people who can tolerate these cooked or processed allergens are less likely to experience a severe reaction; discuss this with your doctor or allergy specialist.

It is important to remember that, even if you have only had a mild reaction in the past, you may react more severely in future. Equally, many people who have reacted severely in the past have mild symptoms on subsequent exposure to their allergen(s). Unless you know you are low risk, avoid taking any chances!

If a product does not have a warning, does this mean it is safe?

Just because a product does not have PAL, this does not mean there is no risk of allergen cross-contamination. It may mean the food company has:

  • Done a thorough risk assessment and the product has no risk of allergen contamination,
  • Not done an assessment and there may or may not be a risk.

How can I make sure the food I buy is safe?

  • Buy pre-packed foods where possible as they are much safer
  • Read the ingredients list on pre-packed foods thoroughly even if you have bought the product before
  • Buy from companies that you know use PAL responsibly. Check retailers' and manufacturers' websites for allergen labelling policies and, if you are still unsure, contact them directly
  • If you are buying food sold loose, such as in a supermarket/ market or in a catering outlet, make sure you advise staff that you have a severe food allergy and ask which foods do not contain your allergen(s). It may be safer to avoid buying foods from bakeries or deli counters, as they are likely to be a greater risk than pre-packaged foods
  • Never make assumptions about what is in a food. Recipes can differ from one product to another or from one establishment to another. Recipes that “traditionally” use certain allergens may sometimes use different allergenic ingredients. For example, pesto sauce usually contains pine nuts but some recipes use cashews or other nuts.

Are there any types of product that are at particular risk of allergen cross-contamination?

Because of the way certain products are made (e.g. cleaning with water might not be possible), there is a greater risk of cross-contamination with high-risk products, such as:

  • Peanuts and tree nuts in chocolate and confectionery

  • Milk in plain chocolate

  • Fish in frozen pizza

  • Sesame in bread and cookies/biscuits

  • Celeriac and mustard in spices and seasoning

If there is a genuine risk of contamination to a particular product or dish will the allergen always be present in every product purchased?

No. Some allergens, such as nuts or seeds, are what is called 'particulate' (bits), which means a piece of nut or seed may be present in one piece of chocolate but not in another. Ingredients, such as milk and milk powders, are usually 'homogeneous', which means they are dispersed equally throughout the product, so each piece is likely to contain milk.

Also, a batch of non-nut chocolate that has been made immediately after nut-containing chocolate on the same machinery has a greater risk of cross contamination than a batch produced at the end of the production run. A batch of plain chocolate produced immediately after a run of milk chocolate is very likely to contain high levels of milk.

You cannot, therefore, assume that if you have eaten a product with a PAL before and not reacted that the same product will always be safe.

Are products that say “may contain traces of …”, "unsuitable for people with … allergy” or similar any more or less of a risk than those that say “may contain”?

There are lots of different phrases that can be used to inform food allergic customers about a possible risk of allergen contamination. As PAL is not a legal requirement, there are no legal definitions for any of these terms and the wording does not indicate any particular level of risk. Also, there is no legal definition or agreed quantity of "trace". A product with "may contain traces" could be just as much of a risk or more than one stating “may contain”.

If a product states “may contain nuts” does that include peanuts?

Although nuts and peanut are separate allergens as far as mandatory allergen labelling is concerned because PAL is not a legal requirement companies can use this term to mean just tree nuts or tree nuts and peanuts. You would need to check with the food business concerned to be sure. Also, they do not have to state which nuts are used in the factory. If you are only allergic to one or two nuts, and are able to eat others without a problem, you might like to ask the company which nuts are used.

Why do products that did not have PAL suddenly carry these warnings?

From time to time, food manufacturers change the recipes of products and/ or may introduce new allergens into a factory or products that share machinery with a food that does not contain that allergen. A manufacturer may also move production of a previously “safe” product to a different factory or part of a factory where allergens are present. This actions can create new risks of contamination for foods that were previously “safe”. If the manufacturer is unable to eliminate or remove the risk of contamination, they are likely to add PAL.