Definition
A firework has no legal use-by date in the food sense, but the manufacturer prints an expiry date or a shelf life on the label, generally three to five years under proper storage. Beyond that, humidity and ageing of the compositions degrade reliability: ignition delays, weakened effects, duds. The batch number, together with the registration number required by Implementing Directive 2014/58/EU (notified body, year, product number), ensures the traceability of each article from the factory; manufacturers and importers must keep the register for ten years. In the event of an incident or a recall, that number identifies every article concerned. A serious pyrotechnician therefore manages stock by batch, not only by reference.
In practice, for the display company
Firing the oldest batches first saves finding 2021 cartons in October. PyroDesk records batch, registration number and expiry on receipt, offers the oldest batches first when a firing plan is built and flags those nearing their limit before the season.