The design of a manual soap dispenser is generally determined by whether the soap comes in liquid, powder, or foam form.
William Shepphard patented liquid soap on August 22, 1865. Minnetonka Corporation introduced the first modern liquid soap and cornered the market by buying up the entire supply of the plastic pumps needed for the liquid soap dispensers.
Dispensers of powder soaps, such as borax, often take the form of a metal box with a weighted lever; when the lever is pressed, a handful of soap is released.
Manual dispensers of foam soap often consist of a large button which squeezes the foam out of a tube. Many liquid soap dispensers operate in this way as well. A few dispensers operate with a lever that pulls forward and squeezes the soap out.
An automatic soap dispenser is a hands-free dispenser of soap, but can be used for other liquids such as shampoo and hand lotions. Home dispensers are often battery-powered. The touch-free design operates when a sensor senses motion under the nozzle, and dispenses the liquid. Automatic soap dispensers are becoming increasingly popular in public restrooms around the world.
The electronic components of an automatic soap dispenser allow for a timing device or signal (sound, lights, etc.) which can indicate to the user whether they have washed their hands for the correct amount of time or not.
Ultrasound detecting dispensers for water and "soap" have particular virtues for operating theatres and treatment rooms.