Manufacturing or expiry dates are not required for fertilisers. The primary reason is that fertilisers do not lose their efficacy if stored in accordance with the manufacturer's guidelines. However, protected fertilisers should be used within 6-12 months in order to maintain the effectiveness of the inhibitor. In any event, the nutrient content of the fertiliser will be stable as for other fertilisers.
Fertiliser is made up of a variety of natural minerals and other elements that do not break down during storage, allowing unused fertiliser to be carried forward from year to year thereby ensuring no unnecessary disposal of unused stocks.