A lorry which caught fire, closing the M6, was carrying a cargo of sports drink powder.
The heavy goods vehicle was wrongly thought to be loaded with tins of dog food when exploding debris was showered across both carriageways of the motorway near Stafford services.
Emergency crews were called to the scene at about 5.13am on Wednesday.
A spokesman for Staffordshire Fire and Rescue Service said: "It was initially believed that the load contained tinned dog food, with tins exploding in the fire.
"However, upon closer inspection it has been established the tins actually contain sports drink powder. The mixed load also contained white goods, malt grain, floor tiles and chocolate eggs."