An inquest into the death of a teenage girl who suffered a fatal allergic reaction to a Pret A Manger baguette has found the allergen information on the food packaging was “inadequate”.

Natasha Ednan-Laperouse died after eating an artichoke, olive and tapenade baguette from the Pret’s Heathrow Terminal 5 branch. The 15-year-old was unaware that the sandwich contained sesame, which she was allergic to. 

Delivering his conclusion, Coroner Dr Sean Cummings said Ednan-Laperouse died of “anaphylaxis”, adding: “The baguette was manufactured to Pret specifications and contained sesame to which she was allergic.

“There was no specific allergen information on the baguette packaging or on the (food display cabinet) and Natasha was reassured by that.”

The coroner will write to the environment secretary, Michael Gove, to raise the question of whether large businesses should be able to benefit from regulations that allow reduced food labelling for products made in shops, rather than offsite in a factory.

Reading a statement outside court, Ednan-Laperouse’s father, Nadim, said the inquest “should serve as a watershed moment to make meaningful change to save lives”. 

He also highlighted the fact the inquest found “there have been a number of previous serious allergic incidents, involving sesame seeds at Pret A Manger before our daughter died”.

“It feels to us that if Pret A Manger were following the law, then the law was playing Russian roulette with our daughter’s life,” he told reporters. 

“It’s clear that the food labelling laws as they stand today are not fit for purpose and it is now time to change the law.” 

Pret’s chief executive Clive Schlee has said the company is “deeply sorry for Natasha’s death”. 

“We cannot begin to comprehend the pain the family have felt, and the grief they will continue to feel,” he said. “We’ve listened to everything the coroner and Natasha’s family have said this week and we will learn from it.

“All of us at Pret want meaningful change to come from this tragedy. We will ensure that it does.”

Earlier this week, the inquest at West London Coroner’s Court was told the packaging failed to mention that sesame seeds were “hidden” in the dough.

Food companies are required to warn customers about allergy risks either on signs and packaging or orally, usually meaning they are told to inquire themselves.

Pret chose to deliver allergy information orally and was supposed to have stickers within fridges telling customers to ask staff members for details.

Natasha, from Fulham, south-west London, collapsed on a British Airways flight from London to Nice, on her way to a four-day break with her father and best friend.

The airline also came under scrutiny during the inquest, as the coroner questioned why cabin crew had not used the defibrillator at the back of the plane to treat the 15-year-old. 

The teenager suffered from numerous allergies and reacted badly to the sesame seeds, which caused her throat to tighten and vicious red hives to flare up across her midriff, eventually triggering cardiac arrest.

Two epipens were jabbed into her legs, but the symptoms did not abate and she was declared dead the same day at a hospital in Nice.