Natasha Ednan-Laperouse died from an allergic reaction after eating a sandwich with sesame in it.
King Charles praises "Allergy School" set up by the parents of Natasha Ednan-Laperouse to improve awareness.
Calls for change stem from the family of a teenager who died after an allergic reaction to a meal out.
The family of Celia Marsh, who had a severe dairy allergy, want more done to protect others.
More than half of firms tested by Trading Standards in Devon and Somerset break labelling rules.
Tanya Ednan-Laperouse and Emma Turay say more needs to be done as the deaths were "preventable".
The recommendations follow the death of Celia Marsh who ate a dairy-contaminated Pret a Manger sandwich.
Celia Marsh, who had a severe dairy allergy, collapsed while on a shopping trip with her family.
The trial has been set up by the family of Natasha Ednan-Laperouse, who died after eating a sandwich.
