Tips For Storing Baking Soda

Is there a reason NOT to store baking soda in an airtight container? I was just wondering because it always comes in a cardboard box that doesn’t really seal shut instead of a carton with a snap on plastic lid (like baking powder).

I’ve been having a problem with my baking soda going “bad” I do a lot of canning this time of year and as a result, my kitchen (in fact my whole house – small single story) gets quite humid at times. I know that baking soda absorbs moisture from the air and this reduces its potency. As a result, I keep having quick bread failure. I know now, after a lot of wasted ingredients, to always “test” my baking soda first. I know baking soda is cheap, but I hate to keep buying a new box every time I want to make a batch of cookies or quick bread. So, I thought I should start storing it in a ziplock bag or plastic container. BUT was wondering if there was a reason it shouldn’t be stored air tight. I mean why doesn’t Arm & Hammer package it in an air tight container?