Pret a Manger has agreed to full ingredient labelling on all its freshly made products following the case of Natasha Ednan-Laperouse, who died after having an allergic reaction to one of its baguettes.

Natasha, 15, collapsed on a British Airways flight from London to Nice on 17 July 2016 after eating an artichoke, olive and tapenade baguette she bought at a Pret outlet at Heathrow airport.

The baguette did not have any allergen advice on its wrapper. There was no requirement for it to do so because of reduced labelling requirements for food produced on-site.

At an inquest into Natasha’s death last week, the coroner expressed concerns about these regulations.

Responding to evidence provided, Dr Séan Cummings, the acting senior coroner for west London, said: “It seems on the face of it a bit strange that a local sandwich shop can benefit from that regulation ... but that an organisation that sold ... 218m items [a year] could also benefit from that regulation ...

“A cynic might think it was almost a device to get round regulation relating to information on food allergens.”

Under current regulations for items made in-store, it is sufficient for general allergen warnings to be posted around the shop, rather than on the packaging, and for specific advice to be given orally by staff.

Pret has announced it will go further than the regulations required by introducing full ingredient labelling, including allergens, to all products freshly made in its shop kitchens.

In a statement, the Pret chief executive, Clive Schlee, said: “I want to say again how deeply sorry we are for the loss of Natasha. I said we would learn from this tragedy and ensure meaningful changes happen.

“I hope these measures set us on course to drive change in the industry so people with allergies are as protected and informed as possible. Nothing is more important to Pret right now.”

The company said “full ingredient labelling will be introduced to all products that are freshly made in its shop kitchens. The labels will list all ingredients, including allergens.”

The coroner said Natasha died of anaphylaxis after eating the sandwich containing sesame, to which she was allergic. Her father, Nadim, said she died because of “inadequate food labelling laws”, and joined the rest of her family in calling for a change in the law to save lives.

Natasha’s parents gave a qualified welcome to Pret’s announcement. Nadim and Tanya Ednan-Laperouse said: “We cautiously welcome the decision by Pret a Manger, and we hope this will quickly lead to improved labelling across all their stores.

“Pret says it has recognised there is much more it can do – we agree. We will be inviting them to meet us to outline how we think they can contribute to genuinely meaningful change. We would like to thank the public and the media for all their ongoing incredible support.”

Jill Paterson of the law firm Leigh Day, which is representing the family, said: “The decision by Pret a Manger concerning labelling on all their products is to be welcomed, but deeds mean more than words.

“We will be working closely with our clients to arrange a lasting legacy for Natasha, not just new legislation but also meaningful change for all people with allergies.”

On Tuesday, Theresa May said the government would look at companies’ responsibilities in relation to food labelling.

Asked whether the government would bring in a “Natasha’s law” to try to prevent further deaths of this kind, May told the BBC: “Obviously, this was an absolutely tragic case and our thoughts are with her family and friends over what happened.

“We have obviously to look at this issue, we have to look at the responsibility of individual companies as well. This is something that has been an absolute tragedy, and our sympathies and condolences are with her family and friends.”