Due to the present heat, its very important your spice mix jar is stored in a very cool place, preferably cold refrigerator!
Do not store in cupboards or anywhere close to heat source especially not near your cooking stove please!
The SMD spice mic is free from all artificial additives, including preservatives.
There is likelihood for your mix to grow weavils because of the heat, just as beans grow weavils.
Do not fear if it does, it only shows that the heat is too much and just like beans, you could sieve and pick them out.