Schools are constantly being urged to promote healthy eating, environmentalism and entrepreneurship among their pupils.
But when a group of students at Priory Sports and Technology College in Preston devised a scheme to sell nutritious, locally grown food, they fell foul of health and safety rules - because their product was too fresh and lacked packaging.
In the kind of Zeitgeist-grabbing initiative that might impress Jamie Oliver or Sir Alan Sugar: teenagers on the school's Young Enterprise team created do-it-yourself soup kits, complete with raw organic vegetables and recipe cards.
The recipes, including one for leek and Stilton, were the creation of pupil Sam Black, Lancashire's young chef of the year. Gimme 5, the teenagers' company, swiftly sold more than 50 of the pound;7.50 boxes, and set up a website explaining the food's origins. They then won three prizes at the local heats of the youth business competition earlier this month.
But, the very next day, the team was disqualified.
Officials from Young Enterprise, which oversees the programme, said the soup kits could not qualify for the competition because all products sold under the scheme must have a shelf-life of three months.
Other breaches of the rules included the lack of a recognised brand name and the fact that the food was not pre-packaged.
Jim Hourigan, the headteacher, said he was furious because the eight Year 10 and 11 pupils had worked incredibly hard on the project and the school had spent pound;274 to enter the team. He said details of the business plan had also been agreed by an advisor from Young Enterprise North West.
"The food was all locally sourced, so we rectified the labelling problem by putting the farm labels on the boxes," said Mr Hourigan.
"I told Young Enterprise that vegetables shouldn't have to be wrapped - they come in their own wrapping. The insinuation is that the pupils might poison someone by handling the vegetables.
"It's ridiculous. The rule on a minimum shelf-life is designed to prevent pupils selling prepared foods like cakes."
Mr Hourigan said he was also angry that pupils were being given conflicting messages about healthy eating and locally sourced products.
Young Enterprise UK said the ban on fresh food was a condition of the insurance policy it takes out on behalf of all Young Enterprise companies.
Rachael Anderton, the deputy chief executive, said: "There are similar rules on things like cosmetics and henna tattooing because of problems like allergic reactions.
"It's a terrible, terrible shame that the pupils got to this point before finding out they had broken the rules.
"However, they need to remember the competition is not the most important aspect - it is setting up and running a company."
She added that the school had been supplied with full details of the rules.
Fordham Primary, near Ely, Cambridgeshire, this week had to ditch plans to hatch chicks in the classroom after health officials demanded risk assessments and a guarantee that the eggs were salmonella free.