How long does glow in the dark powder last?

We have powders made with:

1. Zinc Sulfide

   • may have pungent smell
   • Glow time 10 to 15 minutes
   • Lifespan is around 5 years

2. Strontium Aluminate

   • Ultra Green and BVlue are the brightest
   • Glow time between 2 to 12 hours
   • Lifespan over 10 years