Does your box of baking soda look like this?
Mine does. To keep it safe from spills, I cleaned a plastic container that held our grated Parmesan cheese and stuck a label on it.
Open the one side of the top and use in the fridge to absorb smells, or keep it in your pantry and use the other side to scoop out for when you're baking. Super cheap.
(FYI- the label is a blank address label, cut with fancy scissors which I wrote on! Free and easy!)