There are many people who are hypersensitive to mold and are selective when determining their diet. Mold gets energy from sugar and many people who have been diagnosed with mold allergies watch their sugar intake. Always consult your doctor or dietitian when determining any allergy.
Over time all foods will become moldy. Shop often and buy small quantities, for shelf life read labels of all the foods you buy. And as organic foods are deemed better for you take into account their short shelf life as they tend to mold quicker with of the lack of artificial preservatives.
Thanks for asking this important question, Jeanne!
Pancake mix does not generally contain yeast, the source of leavening in typically baking soda, baking powder or the like. When buying any dry ingredients like pancake mix I will re-package into an airtight container or ziplock bag for freshness.
When using yeast packets for baking I keep them refrigerated to not start the yeast reaction before needed.