Dear Eartha,

I’ve noticed that baking soda is helpful in all sorts of household ways. What is it and why does it have so many uses? — Ruth, Frisco

Baking soda is incredibly useful — by one count, it has more than 500 uses in over 10 industries. North America has a 700,000 ton-a-year market for baking soda. But what is it? Scientifically speaking, it is a chemical salt compound composed of sodium ions and bicarbonate ions, aka 100-percent sodium bicarbonate. The natural mineral is nahcolite (which is part of the natural mineral natron). The fine powder, which we find in the store, can be produced in one of two ways: either it is obtained through the Solvay chemical process or from a processing trona ore which occurs naturally. Both are identical in their chemical makeup, and there is no evidence that one is safer than the other. However, it appears that chemical production has a larger carbon footprint.

Trona ore dates back 50 million years and is primarily found in the land surrounding the Green River in Wyoming. The deposit at the Green River is estimated to be 200 billion tons of pure trona ore and is large enough to meet the entire world’s baking soda needs for thousands of years. Colorado is North America’s second largest producer of baking soda from trona ore from the Piceance Creek Basin near Rifle.

The native chemical and physical properties of baking soda accounts for its wide range of uses. It neutralizes odors chemically rather than masking or absorbing them, making it great for bath salts and deodorants. Baking soda maintains a pH of 8.1 (7 is neutral), even when acids (which lower pH) or bases (which raise pH) are added. Its ability to tabletize makes it an excellent effervescent ingredient in antacids and denture cleaning products. Its crystalline structure provides a gentle abrasion that helps remove dirt without scratching sensitive surfaces. When it is mixed with an acid (like lemon juice), baking soda reacts making bubbles and giving off carbon dioxide gas which causes dough to rise.

Since carbon dioxide is heavier than air, baking soda can smother flames by keeping oxygen out making it a useful agent in fire extinguishers. It absorbs sulfur dioxide and other acid gas emissions making it useful in controlling air pollution. It also reduces the level of lead and other heavy metals making it helpful in water treatment. It’s even helpful in killing cockroaches because once consumed it causes internal organs to burst due to gas production. And during the Manhattan Project (to develop the atomic bomb), baking soda was used to wash out uranium from contaminated clothing.

Indeed, baking soda has been a part of mankind’s history for a very long time. Natron’s useful properties were discovered by early Egyptians who used it as soap and to make mummies. But it wasn’t until 1843, when a British chemist made the first version of baking soda chemically to help his wife who was allergic to yeast, that it became readily available and primarily used in baking. During colonial times, baking soda was imported from England, but, by 1846, a factory was established in New York to manufacture baking soda for commercial sales domestically. One owner’s son owned a mill called the Vulcan Spice Mills. Vulcan, the Roman god of forged metal and fire, was repressed by an arm and hammer, so the new baking soda company adopted the arm and hammer logo as its own. Today the Arm & Hammer brand of baking soda is one of the most widely recognized brand names in pop culture.

By the Roaring ’20s, baking soda was being used to treat the cold and flu virus and was touted by the Good Housekeeping magazine for being useful in the home. By the 1930s, it was widely advertised as a “proven medical agent.” Flash forward to the 1970s and Arm & Hammer was the sole sponsor of the very first Earth Day helping it gain attention as an eco-friendly alternative to chemical cleaners. And in the ’70s people discovered how useful a box of baking soda is in the fridge to keep food fresh. In 1986, the Statue of Liberty got a baking soda scrub for its 100th birthday, leaving its inner copper walls undamaged and completely clean. Today, it is one of the most popular Pinterest pins for its versatility. Who is willing to bet that in the future we will continue to find uses for this versatile and proven powder!

Ask Eartha Steward is written by the staff at the High Country Conservation Center, a nonprofit organization dedicated to waste reduction and resource conservation. Submit questions to Eartha at eartha@highcountryconservation.org.