i found out about silica gel & limestone. there are different types of silica gel. all are non toxic. the food type is used in things such as beer,soy sauce & vinegar to keep them clear.the type to use for keeping things dry are colored blue & when they absord moisture they turn pink, so you know they have to be replaced.they are available from www.confectioneryarts.com.the limestone also comes in different types. the food type is fed to poultry & farm animals to make their shells & bones harder. it has calcium in it. according to albert uster the limestone is completly natural & the silica gel is manufactured,but since they only sell limestone,they would say that.remember,this is not being put into the food. there will be parchment or plastic or somethiing in between the items & the dessicants.i think that should help anyone who wanted to know this(i did)