Why is baking soda stored in cardboard boxes?

Baking soda is not typically stored in cardboard. Most baking soda is sold in plastic containers, such as plastic bags or plastic bottles, to keep the product fresh and protected from moisture, air, and contamination. Cardboard boxes are not airtight and can allow air and moisture to enter the container, which can cause the baking soda to lose its potency and become contaminated.