Why does baking soda reduce smells?
What are the properties of baking soda that allow it to alleviate nasty odours in my refrigerator?
We think that it's because bicarb, or bicarbonate of soda, can change the acidity of things. The things that cause smells are generally very volatile chemicals. These are usually cyclical chemicals - ones that have carbon rings and things like that in them. Basically, if you can do chemical reactions between them and the bicarbonate of soda, then they might change their properties and become less volatile. This stops you getting so many smelly chemicals released into the air.