But when Raffi began vomiting Mr Pownall looked at the label again and discovered it was actually a gluten-free bar containing milk powder.
He tried to help his son by giving him his inhaler and EpiPen before calling for an ambulance.
Raffi was taken to Royal Blackburn Hospital but was pronounced dead at 5.43pm the same day.
Coroner Richard Taylor recorded a conclusion of accidental death as a result of anaphylaxis, a severe and potentially life-threatening reaction to a trigger such as an allergy.
Mr Taylor told the inquest that Raffi had “inadvertently ingested a small piece of chocolate containing milk powder that was believed to be ‘free from’.”
“His father went to have a look at the chocolate bar again and checked the ingredients and found that it wasn’t in fact free from dairy, but contained milk powder as it was a gluten-free bar,” the coroner added.
“He explained that Raffi had previously vomited on occasions when he’d drank milk and then recovered. But this time he was sick and became hot.
“His father grabbed his inhaler and EpiPen but it was clear they were not working and the emergency services were called.
“Mr Pownall did everything he could to save his son.”
Following Raffi’s death, teachers described him as ”lovely boy who was a pleasure to teach and would be missed dearly”.
A family friend said he was a “beautiful child, full of life, intelligent and superseding his age”.
After the inquest a Morrisons spokesman said: “Our deepest sympathies are with Raffi’s family at this difficult time.”
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