Food outlets must inform public about 14 allergens ranging from nuts and milk to mustard and lupin seeds, often used in flour.
Rules aimed at ending the "Russian roulette" food-allergy sufferers face when eating in restaurants, take-aways, schools and hospitals come into force in Britain on Saturday in a move safety watchdogs hope will cut an annual toll of 10 deaths a year and more than 5,000 hospital stays.
Food outlets will have to provide details about 14 allergens, including nuts, milk, mustard and lupin seeds, which are often used in flour. Information has to be listed on menus, chalkboards or information packs, or customers must be able to get written or spoken details from staff.
An estimated 2 million people in Britain, many of them children, are thought to suffer allergic reactions. Fish and chip shops said the EU regulations were "yet another administrative burden" for small, often family-run, businesses.
The rules strengthen requirements on manufacturers to clearly emphasise the listing of allergenic ingredients on prepacked foods, but also apply to shops that sell unpackaged goods such as loose bread rolls, sandwiches, cakes and deli products.
The changes follow an 87% rise in UK hospital admissions relating to allergies since 2002. The Food Standards Agency (FSA) believes the regulations will significantly reduce accidents due to incorrect or insufficient information about allergenic ingredients.
Breaches identified by trading standards officers are likely to incur a sliding scale of sanctions, from further advice and formal enforcement notices, to court action with fines ranging up to £5,000, or more serious penalties where negligence is proved.
Food allergies are thought to affect up to 2% of adults and 8% of children. Other allergens covered by the rules are celery, cereals containing gluten, crustaceans, eggs, fish, molluscs, peanuts, sesame seeds, soya and sulphur dioxide, a preservative in dried fruit, meat products, soft drinks, vegetables, wine and beer.
Chun-Han Chan, of the FSA, said: "This normalises allergen information as something that should be available at all times."
Lindsay McManus, deputy chief executive of Allergy UK, said: "Most of us take eating out for granted, but for someone with a food allergy it is all too often likened to playing Russian roulette. The fear of having an allergic reaction means that many people with a food allergy simply choose to eat at home, knowing that they won't end up in A&E.
"In the past restaurants didn't have to keep records of allergens present in recipes," McManus said: "If there is a lack of knowledge about food allergies in a restaurant, there is an increased risk of a customer having an allergic reaction.
"The new regulations will enable allergic customers to assess whether a restaurant has dishes on the menu that are suitable for them, and we hope that it will encourage dialogue between staff and customers leading to a better understanding of food allergies."
FSA guidance says allergen information can be given through menus, websites, special folders or as part of a conversation with staff. But the information must be correct and consistent.
It also says all ingredients used in dishes must be recorded and up-to-date with containers clearly labelled, while staff must be trained in providing allergy information from their first day in the job.
Stuart Atkinson, vice-president of the National Federation of Fish Friers said: "While we understand the plight of the many allergen sufferers and many fish and chip shops now sell gluten-free fish and chips, this is yet another administrative burden placed on small businesses. Putting together this information is a significant task even if the business has a small menu.
"Once all the interest in the new regulations dies down, we are still stuck with them. Constant vigilance will be required on receipt of deliveries in case a supplier has altered a pie recipe, for example.
"There is no requirement for fish friers to be directly informed of any changes to the ingredients of the products we buy, other than the list of ingredients on the packaging. We must therefore check every delivery for any changes to this list."
Hellal Malik, training secretary of the Bangladesh Caterers Association, representing thousands of businesses, said: "It is about educating everybody, all outlets, to make sure they are really safe."
Top Photo: Fish and chip shops say the new EU food allergy rules are 'yet another administrative burden' for small, often family-run, businesses Photograph: Anthony Hatley/Alamy