How does baking soda absorb odor?

In this brief guide, we are going to answer the question “how does baking soda absorb odor” with an in-depth analysis of the chemistry lying behind the odor-absorbing property of the baking soda. 

So without much ado, let’s dive in and figure out more about it.

How does baking soda absorb odor?

Baking soda’s basic composition makes it an effective odor absorber. When it comes to odors, the majority of the offensive odors are acidic in nature. When baking soda neutralizes the compounds that cause a particularly bad odor, it gives them an ionic character, lowering their vapor pressure and increasing their water solubility. 

Now, what reducing the vapor pressure does is that it makes the smell less available for the nose to detect. So using baking soda for getting rid of the foul smells is an inexpensive and effective remedy. Baking soda is the pure form of sodium bicarbonate with no extra additives. 

As baking soda has the power to neutralize the acids and bases and this particular property of baking soda makes it an excellent odor absorber. So if you want to get rid of foul smells in your refrigerator, your kitchen cabinets or rugs, etc. simply buy some baking soda and let it do its magic.

Other uses of baking soda

Baking soda is used in several ways like as a leavening agent in cooking, as a disinfectant, in fire extinguishers, etc.

In cooking

Baking soda is pure sodium bicarbonate and is a white crystalline powder that has a wide array of uses ranging from baking and cooking (as a leavening agent).

While specifically talking about its use in baking and cooking, when it mixes with any acidic substance, being an alkali, it reacts with the acid and liberates carbon dioxide. This gas is responsible for that risen and fluffy texture of the bread, cookies, etc. that you add baking soda to. Moreover, this is the very reason that many recipes call for adding lemon juice or buttermilk in them.

Milk disinfectant

It has limited disinfection properties, although it may be an efficient fungicide against some species.  Baking soda has proven a reliable solution for used book dealers to make books less smelly since it absorbs musty odors.

Fire extinguisher

Because sodium bicarbonate releases carbon dioxide when heated, it can be used to extinguish small grease or electrical fires by being tossed over the fire. It should not, however, be used to put out fires in deep fryers because the quick release of gas may cause grease to spray.  In BC dry chemical fire extinguishers, sodium bicarbonate is utilized as a substitute for the more corrosive diazepam.

Stain remover

Baking soda is a stain remover and is often used mixed with water or vinegar. The thing about baking soda is that it needs to be mixed with some acid for its reaction (it is basic and reacts with the acid to liberate carbon dioxide). So if it is used with the acid, it won’t leave any stain behind but if you are using it only with water then there could be chances of some white residues being there on your carpet, rug, or sofas.

The most unexpected thing that can happen when you clean your carpet or rug with baking soda is that you have not completely mixed the baking soda with water and afterward, have not cleaned it with enough water, so there can be a bit of white baking soda spots.

So if you are too skeptical about baking soda staining your carpets, it is better to use some commercially prepared stain remover for cleaning your carpets and sofas.

However, if the baking soda is used along with vinegar then there can be chances of the vinegar slightly bleaching the area where you have applied it but the risk of this happening is really low.

You can read how to clean and freshen your laundry with baking soda here.

Neutralization of acids

When sodium bicarbonate combines with acids, CO2 gas is released as a reaction product. In chemical laboratories, it’s typically used to neutralize undesirable acid solutions or acid spills.  Even though sodium bicarbonate is amphoteric, meaning it reacts with both acids and bases, it should not be used to neutralize bases.

Is baking soda safe to use after the best by date?

The “best by” or “best before” date that is written on the package of baking soda refers to the quality rather than safety so the baking soda doesn’t necessarily go bad immediately after the best before date, however, its action will weaken with time.

This date refers to the time during which you can enjoy the peak quality of baking soda but you can still use baking soda that is past this date as long as it was stored properly.

Other FAQs about Baking soda that you may be interested in.

Where is baking soda in the grocery store?

Can baking soda clog a drain?

Can baking soda burn your skin?


In this brief guide, we answered the question “how does baking soda absorb odor” with an in-depth analysis of the chemistry lying behind the odor-absorbing property of the baking soda.