The soda/acid fire extinguisher is considered to be one of the earliest patented fire extinguishers. Though there are many different accounts as to the invention of the soda/acid fire extinguisher, the first U.S. patent for a soda/acid extinguisher was filed by Almon M. Granger in 1880. The soda/acid extinguisher operates by using the pressure built from a reaction between sodium bicarbonate and sulfuric acid to expel pressurized water onto a fire. The user initiates this chemical reaction by turning the extinguisher on its head and pointing the attached hose toward the base of the fire.

These extinguishers are the largest part of the Koorsen Fire Museum collection, making up nearly 20% of the objects on display. Notable brands in the collection include Elkhart Brass, American LaFrance, and Pyrene. Other soda/acid extinguishers created to be mounted to an apparatus are in the collection, including Stutz, Howe, and Mack extinguishers.