The approximated shelf-life of Vihtavuori gunpowders is a minimum of 10 years, if stored and sealed in its initial containers in a temperature circa 20°C and relative humidity of circa 55 %. All Vihtavuori reloading powders are packed into bottles and canisters and further more in fiberboard packing containers. 1600” https://reloadsworld.com/product/vihtavuori-n133-powder-1-lb/