We All Love Baking Soda, but Where Does It Come From?

If keeping a nontoxic, green home is a priority, then you’ve probably got a box of baking soda tucked away in a cupboard. Perhaps, like me, you’ve got multiple boxes—one in the kitchen, one in the bathroom, and one on the laundry shelf.

It seems that baking soda can be used for everything. It cleans homes, deodorizes furniture, exfoliates skin, kills mold, and polishes silver, all while posing no danger to children or pets. I use it to wash my hair, to make deodorant, to take the stink out of sweaty gym clothes. We go through it at an astonishing rate, buying an extra-large box at least once a month.

Baking soda is an excellent cleaner because it is a mild alkali and can dissolve grease and dirt for easy removal. It also acts as an abrasive, providing useful scouring power. It deodorizes effectively by neutralizing odors, rather than just masking them: "Most unpleasant odors come from either strong acids (like sour milk) or strong bases (spoiled fish). Baking soda deodorizes by bringing both acidic and basic odor molecules into a neutral, more odor-free state."

While it’s great to have a single, all-natural ingredient that can replace so many other chemical-laden ones, with the added bonus of being able to buy it in a recyclable cardboard box (no plastic packaging, yay!), it only recently occurred to me that I didn’t know anything about where baking soda comes from. Is it sourced sustainably? Where and how is it made? Is it a finite resource that could run out, thanks to a generation of enthusiastic DIYers?

The Story Behind Baking Soda

Baking soda (NaHCO3) is a naturally occurring crystalline chemical compound that is often found in powder form. It is mined and then created through a chemical process. Initially it comes out of the ground in the form of minerals nahcolite and trona.

Trona is refined into soda ash (aka sodium carbonate), then turned into baking soda (aka sodium bicarbonate), among other things. When the soda ash is dissolved into a solution through which carbon dioxide is bubbled, sodium bicarbonate precipitates out.

Most of the soda ash comes from Wyoming, which contains the world’s largest trona deposit. There is no risk of depletion anytime soon, according to the Wyoming State Geological Survey:

“The Green River Basin of southwestern Wyoming contains the largest trona resource in the world at over 127 billion tons, of which more than 40 billion tons are reserves (economically minable with current technology). At the current rate of production and assuming a moderate growth in that rate of 1 to 2 percent, Wyoming’s trona reserves should last well over 2,000 years.”

Nahcolite is a naturally occurring sodium bicarbonate that does not contain chemical additives. It is considered the purest form of baking soda and commonly forms when carbon dioxide reacts with the mineral trona, typically in evaporated lake basins:

“[It exists] in large quantities in the central salt body of Searles Lake, California, and as concentrations up to 5 feet (1.5 meters) thick in oil shale deposits... in Colorado, where it is commercially mined. It also has been mined in Botswana and Kenya, and there are sizable deposits in Uganda, Turkey, and Mexico.”

On its website, the Wyoming Mining Association explains how soda ash is currently used:

“Glass making consumes about half of the soda ash, followed by the chemical industry, which uses about a quarter of the output. Other uses include soap, paper manufacturing, and water treatment, and all baking soda comes from soda ash, which means you probably have a box of Wyoming trona product in your kitchen.”

Should We Be Concerned About the Effects of Mining?

Apparently there are two ways to mine for trona. One is a "room-and-pillar" method that involves carving out underground rooms supported by pillars. The mineral is scraped off the walls and removed by conveyor belt. The other is a liquid injection method, where miners inject hot water underground to dissolve the minerals, pump out the liquid, and then evaporate the water to get at the leftover crystals. The mineral is then processed:

“The purification process begins with crushing the ore, which is then heated to drive off unwanted gases. This transforms the trona into a sodium carbonate. Water is added to this substance, which is then filtered to remove impurities. The water is evaporated and the resulting slurry is placed into a centrifuge to separate the remaining water from the soda ash crystals. The crystals are then sent to driers, screened, and sent to storage bins for transport.”

It’s undeniable that these methods are invasive and destructive, as any kind of mining would be. They use energy and emit toxic volatile organic compounds (VOCs) and methane. Trona processing in the U.S. generates air pollution, due to coal-powered facilities, and endangers the sage grouse’s habitat. In eastern Africa, soda ash processing plants disturb flamingo populations.

It’s far from ideal.

But when you consider that everything has a footprint on this earth and all products come with an intrinsic production cost—and that baking soda is capable of replacing countless other, much worse, lab-contrived substances in our daily lives—it remains a pretty decent option. The fact that it comes from the U.S., too, and isn't imported from far away is an asset. In other words, you can go forward in your baking soda-fueled life without feeling terribly guilty.