question: What’s the difference between dish soap and hand soap?
comment: Different pH values and oil additives/perfumes. That’s it. You can use dish soap as your only soap, and just add a bit of baking sofa or vinegar until your skin is happy. The actual soap is the same for all soaps - one end binds to water, the other to oil.
passages: A classified ad that appeared on 25 March 1820 in the "Sydney [Australia] Gazette and New South Wales Advertiser" lists auction items that include soap dishes. The Oxford English Dictionary gives a later "first evidence of use" for the term "soap-dish" as 1837 (in "The Pickwick Papers" by Charles Dickens).
   Soap dish
  
  A soap dish is a shallow, open container or platform where a bar of soap may be placed to dry after use. Soap dishes are usually located in or near a sink, shower, or bathtub. Most soap dishes are made from waterproof materials such as plastic, ceramic, metal, or glass, though some are made from bamboo. A china saucer or sponge may serve as a soap dish. A soap dish accommodates bar soap, whereas a soap dispenser accommodates liquid soap or foam soap.
  
  Section::::Design elements.
   Elements in the design of a soap dish include safety, ventilation, cleanliness, placement, aesthetics, and cost. When a soap dish is part of a bath accessories set, coordinated group design may be utilized. Notable soap dish designs include Leonard L Hierath's May 2018 US Patent #US-9962042 Article Support (soap dish) US Patent and Trademark Office; Robert A. Pitton's 1956 US patent for a reversible, hemispherical soap dish and Bernard Cohen's October 2017 design for the "SoapAnchor" (patent pending).
  
  Section::::Design elements.:Safety.
   Clinical psychologist Barbara Lichner Ingram, in her book on clinical formulation, used the word "hypothesis" in place of "assessment", resulting in the acronym SOHP instead of SOAP.
  
  Section::::Components.:Plan.
   Since they are salts of fatty acids, soaps have the general formula (RCO)M (Where R is an alkyl, M is a metal and n is the charge of the cation). The major classification of soaps is determined by the identity of M. When M is Na or K, the soaps are called toilet soaps, used for handwashing. Many metal dications (Mg, Ca, and others) give metallic soap. When M is Li, the result is lithium soap (e.g., lithium stearate), which is used in high-performance greases.
  
  Section::::Kinds of soaps.:Non-toilet soaps.
   BULLET::::- Dishwashing liquid has uses as an ingredient in making homemade garden pest deterrents. Oregon State University's Cooperative Extension Service notes the use of dishwashing liquid to get rid of spidermites. Dish soap has also been used to deter aphids. In some instances, the dish soap may be toxic to plant leaves and cause them to "burn". Use of soap or dish detergent to help spread pesticide on plants is noted by University of Georgia extension service, but not recommended.
   An example of a product classified according to its form is personal hygiene soap. When in the form of a bar, cake or moulded shape, such soap is classified under subheading 3401.11, which provides for "Soap and organic surface-active products and preparations, in the form of bars, cakes, moulded pieces or shapes, and paper, wadding, felt and nonwovens, impregnated, coated or covered with soap or detergent: For toilet use (including medicated products)". Conversely, liquid personal hygiene soap is classified under either 3401.20, which provides for "Soap in other forms", or 3401.30, which provides for "Organic surface-active products and preparations for washing the skin, in the form of liquid or cream and put up for retail sale, whether or not containing soap".
   Because of their association with hand washing and hygiene, soap dishes themselves are often the focus of cleanliness. To aid in cleanup, some self-draining soap dishes are designed to allow soapy residue to collect in a compartment below the raised bar of soap. Other such soap dishes funnel the soapy reside directly to the adjacent sink or bathtub, necessitating strategic placement of the soap dish.
  
  Section::::Design elements.:Placement.
   Because of their intended use in wet and potentially hazardous environments, most soap dishes are designed with safety in mind. Such features include unbreakable materials, non-slip surfaces, rounded edges, and secure installation elements (e.g., wall mount hardware, a suction cup, or non-skid feet). Depositing or retrieving a slippery bar of soap is facilitated by an open (or semi-open) sided design or by a shallow lip.
  
  Section::::Design elements.:Ventilation.
   A pewter soap dish made in Meriden, Connecticut between 1807 and 1835 is in the collection of the Metropolitan Museum of Art. An 1887 medical journal discusses an operating table that includes a built-in soap dish and an 1892 book on industrial arts shows a soap dish attachment for a scrub bucket. A toy porcelain soap dish likely from the 1890s was unearthed by archaeologist Laurie A. Wilkie at the Oakley Plantation in Louisiana. Wilkie explains in detail the facts surrounding this soap dish that led her to interpret it to be "a little material embodiment of someone's love for a child". By the late 19th century, Sears Roebuck & Company was influencing the spread of the soap dish in American households.
   Vegan soap
  
  Vegan soaps (or vegetable soaps) are made from fats or oils of vegetable origin rather than from saponified tallow or other animal fats. These soaps are preferred by vegans and may be preferred by vegetarians. In addition to fats, the other main ingredient is either wood ash, potassium hydroxide or sodium hydroxide.
  
  Section::::Olive oil soaps.
  
  BULLET::::- Aleppo soap, a Syrian style of soap noted for the inclusion of Laurel oil in its formulation
  
  BULLET::::- Castile soap, a wide-ranging style of soap in English-speaking countries, as originally made in the Castile region of Spain
   Fels-Naptha
  
  Fels-Naptha is an American brand of laundry soap used for pre-treating stains on clothing and formerly as an effective home remedy for exposure to poison ivy and other skin irritants. Fels-Naptha is manufactured by and is a trademark of the Dial Corporation, a subsidiary of Henkel. The soap was originally created around 1893 by Fels and Company and was the first soap to include naphtha. The inclusion of naphtha made the soap very effective for cleaning laundry and dissolving the contagious oil of poison ivy, but was removed as a cancer risk. 
   The type of alkali metal used determines the kind of soap product. Sodium soaps, prepared from sodium hydroxide, are firm, whereas potassium soaps, derived from potassium hydroxide, are softer or often liquid. Historically, potassium hydroxide was extracted from the ashes of bracken or other plants. Lithium soaps also tend to be hard. These are used exclusively in greases.
   In 2010, the United States FDA raised health concerns over triclosan, an antibacterial substance used in some dish liquids. Elsewhere, triclosan has been found to create problems at wastewater treatment plants, whereby it can "sabotage some sludge-processing microbes and promote drug resistance in others." The United States FDA has found that triclosan provides no health benefits over soap and water. As of 2014, at least one state within the United States has banned triclosan in dishwashing liquids.
  
  Many dishwashing liquids contain perfume which can cause irritant or allergic contact dermatitis.
  
  Section::::Brands.
   Solid soap, because of its reusable nature, may hold bacteria acquired from previous uses. A small number of studies which have looked at the bacterial transfer from contaminated solid soap have concluded transfer is unlikely as the bacteria are rinsed off with the foam. The CDC still states "liquid soap with hands-free controls for dispensing is preferable".
  
  Section::::Substances used.:Soap and detergents.:Antibacterial soap.
   Though utilitarian in purpose, soap dishes may be given aesthetic treatment. A soap dish in the form of a whale, for example, was patented in 1961 by Sonia Adelson, with "the mouth portion thereof being adapted to receive and dispense a bar of soap in an amusing, novel and useful manner". Another example is the "Bodoni Soap Dish", a February 2013 design by David Strauss that was inspired by the legacy of Massimo Vignelli.
  
  Section::::History.
  
  A soap dish played a role in a seminal event in the 7th century when Byzantine Emperor Constans II (630-668) was assassinated with one.
   A bar of wet soap relies on ventilation to dry. A number of design elements may be used to increase ambient airflow around the soap, including vented surfaces or surfaces interspersed with bumps, ridges, or slats. Mechanical ventilation has not yet become a widespread design element in soap dishes.
  
  Section::::Design elements.:Cleanliness.
   A comprehensive analysis from the University of Oregon School of Public Health indicated that plain soaps are as effective as consumer-grade anti-bacterial soaps containing triclosan in preventing illness and removing bacteria from the hands.
  
  Section::::Substances used.:Water.
   Finer soaps were later produced in Europe from the 16th century, using vegetable oils (such as olive oil) as opposed to animal fats. Many of these soaps are still produced, both industrially and by small-scale artisans. Castile soap is a popular example of the vegetable-only soaps derived from the oldest "white soap" of Italy.
   A pocket-sized metal soap dish emblazoned with two crossed swords that was in use during World War I (1914-1918) is in the special collections of the Pritzker Military Museum & Library. In 1919, Witter Bynner immortalized a soap dish in his poem entitled "I Evade," which is reproduced here in its entirety: "The look in your eyes / Was as soft as the underside of soap in a soap-dish … / And I left before you could love me."
   For making toilet soaps, triglycerides (oils and fats) are derived from coconut, olive, or palm oils, as well as tallow. Triglyceride is the chemical name for the triesters of fatty acids and glycerin. Tallow, "i.e.," rendered beef fat, is the most available triglyceride from animals. Each species offers quite different fatty acid content, resulting in soaps of distinct feel. The seed oils give softer but milder soaps. Soap made from pure olive oil, sometimes called Castile soap or Marseille soap, is reputed for its particular mildness. The term "Castile" is also sometimes applied to soaps from a mixture of oils, but a high percentage of olive oil.
   Monkey Brand
  
  Monkey Brand soap was introduced in the 1880s in cake/bar form in the United States and United Kingdom as a household scouring and polishing soap. 
  
  Section::::History.
  
  Initially, Benjamin Brooke & Co Ltd, a firm owned by Sidney and Henry Gross, had produced the soap in Philadelphia. The soap's highly abrasive agent was probably pumice.
  
  Lever Brothers bought the company in January 1899 and transferred the production of Monkey Brand soap to Port Sunlight near Liverpool. The name ‘Benjamin Brooke’ (hence Brooke's Monkey Brand) was retained to promote the Monkey Brand soap on both sides of the Atlantic.
   Hard soap
  
  Hard soap or curd soap is a kind of soap; examples are Aleppo soap, Castile soap, and Marseille soap or "savon de Marseille". During the preparation of the soap, common salt (sodium chloride) is added to the liquid soap mass. This leads to the soap mass separating from glycerin, resulting in a harder soap. It can be made using sodium hydroxide.
   Research summaries for three countries listed combined retail value shares that included domestic and international producers: Brazil's domestic producers led hand dishwashing products with Química Amparo, Bombril, and Flora Produtos de Higiene e Limpeza; Poland's Grupa Inco with Ludwik and Lucek brands, and Henka Polska with Pur and Somat brands, led sales with a combined retail value share of 46%; and in Belarus the Russian company PZ Cussons PLC accounted for 24% of retail value shares, with Morning Fresh brand, followed by Procter and Gamble (20%) and Henkel (19%).
   Douglas died in 1847 and his sons Thomas and Alexander took over the business under the name "J.S. Douglas Sons". In 1851, they presented their soap products at the first World Fair in London, where the "Chinese Heavenly Soap" was honored with a medal. In the same year, the brothers developed their "Egyptian Toilette Soap".
  