One in three people with a food allergy has suffered a reaction while eating in a restaurant, cafe or takeaway in the last year, according to new figures.
Nearly one in five of those allergic reactions resulted in a hospital visit, it has been claimed.
Official statistics suggest there are an estimated 58,000 people in Northern Ireland with a food allergy - including 30,000 children.
Food allergy is a rapidly growing problem in the developed world, affecting up to 10% of children and 3% of adults.
Allergic reactions can range from a mild runny nose, skin irritation or stomach upset to severe anaphylaxis, which can be fatal.
The EU Food Information For Consumers legislation was introduced in December 2014, which means that businesses have to make information on 14 allergens available to customers.
Despite this around a third of those with a food allergy have experienced a reaction in the last year when eating out of the home.
The vast majority of these (25%) took place in a restaurant or cafe, with 9% being a result of takeaway food.
In most cases (88%) the reaction was self-treated, with 19% of reactions resulting in a hospital visit.
Almost 70% of respondents to the survey said staff had made basic mistakes with the menu, including confusing eggs with dairy, while 69% said they had experienced staff who did not understand the severity of an allergy when eating out.
More than half of respondents said they have been made to feel an inconvenience as a result of their allergy.
The survey, which was carried out to mark Allergy Awareness Week 2016, found that 83% of respondents have noticed an increase in measures designed to make life easier for allergic consumers - including menus marking out allergens, and staff actively checking food information with the kitchen. More than half of allergic consumers said that their overall experience of eating out has improved - just 6% said it has got worse.
Sharon Gilmore, head of dietary health at the FSA in Northern Ireland, said: "The number of people who have food allergies and intolerances has increased in the last decade and this is something businesses can't ignore. Since the introduction of new legislation in 2014, we're pleased to see real progress in how businesses provide information on allergens but it's an area that still needs improvement.
"We are working very closely with district councils and food businesses to ensure we're providing food people can trust."
Businesses that sell food must now be able to inform customers when it contains any of 14 stated allergens. This can be done verbally or on labels or signs.
Meanwhile, scientists from Queen's University have called for more to be done to protect people with food allergies.
Professor Chris Elliott is a renowned expert on food fraud and traceability and led the review of the UK's food system following the 2013 horse meat scandal.
He said: "The food supply chain is highly vulnerable to fraud involving food allergens, risking consumer health and reputational damage to the food industry.
"While efforts have been made to improve food labelling and introduce the concept of threshold quantities for allergens, these depend on being able to accurately detect and quantify allergens. Gaps in the current system mean that it is difficult to achieve this."