Murphy Oil Soap is a cleaning product marketed by Colgate-Palmolive. In 1910, Jeremiah Murphy, director of the Phoenix Oil Company, bought the formula for Murphy Oil Soap from a recent immigrant from Germany. The soap, with its potassium vegetable oil base, and no phosphates proved to be very popular in Ohio. The company continued to be run by the Murphy family for 80 years, when they sold to Colgate. It is available in a concentrated liquid form which is then mixed with water, as well as pre-diluted form which comes in a trigger spray bottle. Commercials for the product state that the product is ideal for cleaning wood surfaces.
The other constituents of Murphy Oil Soap are sodium EDTA, propylene glycol, fragrance, surfactants, and water.
Murphy Oil Soap is commonly used to clean and polish horse tack, such as bridles and saddles. It is also commonly used to clean black-powder weapons after use, since the lack of petroleum-based oil and the presence of vegetable oil lessens the amount of sludge that is created when cleaning black powder residues from weapons. It has also been found to efficiently remove the black powder residue that builds up on automobile wheels and hubcaps from the disc brakes. Murphy Oil Soap is also an excellent lubricant to use with water when throwing clay on a potter's wheel. It has also been found to quickly and easily dissolve water-based inks, such as Crayola marker ink, from acid-free paper.
Diluted Murphy Oil Soap (2-4%) is often used by home gardeners as an insecticidal soap spray.