Niter

Mining

 * Mine niter (level 13)

Crafting

 * Gunpowder (level 11)
 * Sulfanilamide (level 22)
 * Ammonia (level 25)
 * Fertilizer (level 25)
 * Explosive (level 29)
 * Paracetamol (level 38)
 * Stun grenade (level 42)
 * Aramid fiber (level 60)