"Sodium bicarbonate is obtained in two different ways. One is called the Solvay method, which is when sodium chloride (table salt) is heated with sulfuric acid. That produces sodium sulfate and hydrochloric acid. The sodium sulfate is then heated with coal and limestone to form sodium carbonate, or soda ash. Soda ash is then treated and refined to produce what we know as baking soda...though the chemicals used in this process present some problematic disposal issues."
The other method is to mine it from trona deposits. In Green River, Wyoming, there is a 2 billion ton deposit of trona which is reported to be large enough to supply the world with soda ash and sodium bicarbonate for thousands of years.
One interesting development is that in 2010, Skyonic Corporation in Austin, Texas was awarded an EPA grant to create baking soda from CO2 it captures from air pollution.
So, the fact is that baking soda production requires either mining or creates hazardous bi-products. But, it is a non-toxic product that replaces far more hazardous cleaning chemicals in your home. By no means do I want to deter anyone from using baking soda or sound an alarm bell about this, because as we know there is little that we use that is 100% perfect or impact-free. But I do like to learn how things come to be and know that many of you do, too.
(Image: Dr. Frank Lipton / Annie R. Bond)