Dishwashing liquid

Dishwashing liquid (washing-up liquid in British English), also known as dishwashing soap, dish detergent, or dish soap, is a type of detergent used in dishwashing. It is usually a foamy mixture of surfactants with low skin irritation that consumers use primarily for washing glasses, plates, cutlery, and cooking utensils. Dishwashing liquid can be used for other purposes, like creating bubbles, washing clothes, and cleaning wildlife affected by oil spills. Detergent for dishwashers is also available in non-liquid forms, such as cartridges, gels, packs, powder, and tablets.^[1]

Dishwashing liquid in use

Dishwashing liquid with different dyes/scents

Dishwashing liquid has been in use for a long time in various compositions and under different conditions.^[2][3][4] Most modern dishwashing liquids function best with hot water. However, there are dishwashing products designed to work well with cold water or seawater.

History

Main article: Detergent

Before the invention of detergents in Germany during World War I,^[4] people used washing soda for dishwashing.^[2][3] Liquid detergent manufacturing for dishwashing began in the middle of the 20th century. Dishwashing detergent production started in the United States in the 1930s–1940s.^[4][5] Teepol, the first dishwashing detergent in Europe, began production in 1942.^[6]

Composition

Dishwashing liquid may contain bleach, enzymes, and rinsing aids.^[1] The main ingredient is water and the main active ingredients are detergents. Dishwashing liquid uses detergent instead of soap because soaps are likely to react with minerals in the water to form soap scum. Dishwashing liquids also use thickening and stabilizing agents.^[7] Other ingredients may include hydrotropes, salts, preservatives, fragrances, antibacterial ingredients, and dyes. Preservatives prevent the proliferation of microorganisms within the liquid. Antibacterial ingredients make it difficult for bacteria to survive on surfaces.^[5]

Alternatives to dishwashing detergents may be homemade, using ingredients such as borax, essential oil, eucalyptus oil, leftover cooking oil, and bar soap.^[8][9]

Water and dishwashing liquid mixing to form foam

Items that may be damaged by some dishwashing liquids (especially with used with hot water or put into a dishwasher) include household silver, fine glassware, gold-leafed objects, disposable plastics, and objects made of brass, bronze, cast iron, pewter, tin, or wood.^[1] Dishwashing liquid components are harder to rinse off rough surfaces than smooth surfaces, which increases the risk of accidental ingestion.^[10]

In hand dishwashing detergents surfactants play the primary role in cleaning.^[5] The reduced surface tension of water and the increased solubility of modern surfactant mixtures allow water to run off dishes very quickly. Additionally, surfactants remove grease and food particles, and may provide foam.^[5]

Surfactant design

Surfactants reduce the surface tension of water: this reduction helps with the cleaning process.^[11] Surfactants have been compared to determine which dishwashing liquid is the most efficient.^[11][12] One study showed that a combination of anionic surfactant and non-ionic surfactant worked better than other combinations.^[11] Another found that a combination of cationic and anionic surfactants worked better than one of non-ionic and anionic surfactants.^[11][12] Anionic and amphoteric surfactants are a less effective combination.^[11][12]

Safety concerns

In 2010, the United States FDA raised health concerns over triclosan, an antibacterial substance used in some dish liquids.^[13] Elsewhere, triclosan has been found to create problems at wastewater treatment plants; it can "sabotage some sludge-processing microbes and promote drug resistance in others."^[14] As of 2025, triclosan has been banned in the United States, the European Union, Canada, Australia, and elsewhere.^[15]

Some dishwashing products contain phosphates. Phosphates make dishes cleaner but can cause harmful algal bloom as wastewater returns to the natural environment.^[16] For this reason, many places have banned this component.^[16] Phosphates can also have harmful health effects when they come into contact with skin.^[5]

Many dishwashing liquids contain perfume, which can cause irritant or allergic contact dermatitis.^[17] It can also cause hand eczema. People with sensitive skin are advised to use hypoallergenic gloves to avoid direct contact with the liquids.^[18] Surfactants that are anionic showed promising results in preventing skin irritation.^[19]

Primary uses

Dishwashing liquid is primarily used for removing food stains and grease from dirty dishes and tableware.^[1][5] Consumers usually scrape heavy soil (large food particles) from the dishes before applying the dishwashing liquid.^[1]

Hand dishwashing

Dishwashing process

Consumers wash by hand if they do not a dishwashing machine or if they have large "hard-to-clean" items.^[5]

Automatic dishwashing

Automatic dishwashing means the use of a dishwasher or other apparatus.^[5] It is generally preferred for convenience or sanitation.^[5] The cleaning is less reliant on the detergent's surfactants and more on the machine's hot water as well as on the detergent's builders, bleach, and enzymes.^[5] Automatic dishwashing detergents' surfactants generally have less foam, to avoid disrupting the machine.^[5]

Other uses

Domestic uses

Reader's Digest notes that dishwashing liquid may be used to kill ants and weeds, to help spread waterborne fertilizer, and to wash human hair.^[20]Good Housekeeping suggests mixing it with vinegar to attract and drown fruit flies.^[21] Oregon State University's Cooperative Extension Service notes the use of dishwashing liquid to get rid of spider mites.^[22]

Washing an oiled gannet with dishwashing liquid

Some other uses of dishwashing liquid are:

• Cleaning mirrors and windows.^[23]
• Cleaning delicate clothing such as hosiery and lingerie.^[24]

• Making decals and vinyl graphics easier to position when applying.^[25][26]
• Making homemade garden pest deterrents.
• Removing coffee, tea, olive oil, soda and fruit juice stains from fabrics.^[27][28]

Industrial uses

Dishwashing liquid is used for inspecting equipment under pressure for leaks, such as propane fittings.^[29][30] It can also be used for inspecting pneumatic tires for flats, as well as for quality assurance during the installation process, and as a mounting bead lubricant.^[31][32][22] Dishwashing liquid can also treat birds in oil spills.^[33][34]

Market share

Market research companies like Euromonitor and Grand View Research collect data on different brands' market share.^[35][36]

Euromonitor International collects market trends of many big brands like Procter and Gamble, Colgate-Palmolive, Henkel, Reckitt Benckiser, Unilever, and Ajax.^[35]

For example, according to Euromonitor International, in 2013 Reckitt Benckiser held the highest retail value share percentages in nine countries:^[35] Italy (31%) and Spain (29%) with the Finish brand; Australia (38%), New Zealand (38%), Austria (32%), Ireland (29%), and Israel (27%), and Denmark (30%) with the Neophos brand; and Portugal (22%) with the Calgonit brand.

As of 2025, the global dishwashing liquids market is valued at approximately US$18 billion.^[37]

See also

• Dishwasher detergent
• Cleaning agent
  • List of cleaning agents
  • List of cleaning products
• Soap
• Green cleaning
• Washing