Baking soda, a naturally occurring chemical formally known as sodium bicarbonate or soda ash, can do much more than raise bread. Enterprising homemakers have long relied on the versatile white powder for everything from cleaning and deodorizing to soothing minor aches and pains. In fact, the medicinal and self-care uses for baking soda were recognized by the United States Pharmacopoeia (USP) more than 150 years ago.