What’s the Difference Between Baking Soda and Borax?

Baking soda and borax are, in many ways, quite similar. Importantly, they’re both naturally-occurring salts that are used as cleaning agents. So, what’s the difference? And are they interchangeable? Let’s take a look.

Baking soda is a chemical compound known as sodium bicarbonate. In nature, it’s crystalline; in our homes, it’s a white, odorless powder that we use to make cakes and muffins rise and to keep our refrigerators smelling fresh.

Baking soda works as a cleaner for two main reasons: First, it’s alkaline. This makes it reactive with acidic things (which include many smelly things). It’s also mildly abrasive, which makes it good for gentle scrubbing.

A naturally-occurring salt known as sodium borate, sodium tetraborate, or disodium tetraborate, borax is also a white, odorless powder — though we would not advise putting it in your cakes. It can be lethal and should be used with caution if you have children or pets in your home.

Borax works as a cleaning agent for the same reasons that baking soda works: it’s alkaline and it’s abrasive. You can use it to clean the drain, clean your dishwasher, deodorize your carpets, and remove rust stains. It’s also helpful in getting rid of pesky bugs (including cockroaches) and killing weeds. And, not related to cleaning, it’s a primary ingredient for making slime — an incredibly popular activity for children. 

There are two main differences between baking soda and borax. Borax is significantly more alkaline than baking soda. Borax has a pH of 9.5 vs. 8 for baking soda. That might make it more effective in certain situations, but it also makes it a harsher cleaning agent.

And then there’s the fact that you can safely consume baking soda, while borax should not be eaten, inhaled, or even exposed to your skin.

That doesn’t mean it’s not “safe.” Rather, it is to say that baking soda is, on the whole, a milder cleaning agent than borax.