Janitorial - janitors and janitorial services in the United States

Janitorial - janitors and janitorial services in the United States

janitor \Jan"i*tor\, n. [L., fr. janua a door.] A door-keeper; a porter; one who has the care of a public building, or a building occupied for offices, suites of rooms, etc. janitor n : someone employed to clean and maintain a building

Soap
Cleansing agent or detergent (see Detergents), made from animal and vegetable fats, oils, and greases; chemically, the sodium or potassium salt of a fatty acid, formed by the interaction of fats and oils with alkali.

HISTORY OF SOAPMAKING
Records mentioning the use of numerous soapy materials and cleansing agents date from ancient times. The purifying agents mentioned in the Old Testament (see Jeremiah 2:22 and Malachi 3:2) were not true soaps but were a product of tree bark ashes alone. The 1st-century Roman historian Pliny the Elder described various forms of hard and soft dye-containing soaps known as rutilandis capillis, which had previously been used by women to cleanse and impart brilliant colors to the hair. Soapmaking was common in Italy and Spain during the 8th century. By the 13th century, when the soap industry was introduced from Italy into France, most soap was produced from the tallow of goats, with beech ash furnishing the alkali. The French, after experimentation, devised a method of making soap from olive oil instead of from animal fats and, about 1500, introduced their discoveries into England. The industry in England grew rapidly and in 1622 was granted special privileges by King James I. In 1783 the Swedish chemist Carl Wilhelm Scheele accidentally simulated the reaction that occurs in the present-day boiling process of soapmaking, described below, when he boiled olive oil with lead oxide, producing a sweet-tasting substance that he called …lsŸss, which is now known as glycerin. This discovery by Scheele led the French chemist Michel Eugne Chevreul to investigate the chemical nature of the fats and oils used in soap; Chevreul eventually discovered, in 1823, that simple fats do not combine with alkali to form soap but are first decomposed to form fatty acids and glycerols. Meanwhile, the manufacture of soap was revolutionized in 1791 by the French chemist Nicolas Leblanc, who invented a process for obtaining sodium carbonate, or soda, from ordinary salt. In the early American colonies, soap was made from rendered animal fats and was processed mainly in the household, but by 1700 many areas derived their main income from the export of ashes and fats used in soapmaking.

INGREDIENTS
Oils and fats used are compounds of glycerin and a fatty acid, such as palmitic, or stearic acid. When these compounds are treated with an aqueous solution of an alkali, such as sodium hydroxide÷a process called saponification÷they decompose, forming glycerin and the sodium salt of the fatty acid. The fat palmitin, for example, which is the ester of glycerin and palmitic acid, yields sodium palmitate (soap) and glycerin upon saponification. The fatty acids required for soapmaking are supplied by tallow, grease, fish oils, and vegetable oils such as coconut oil, olive oil, palm oil, soybean oil, and corn oil. Hard soaps are made from oils and fats that contain a high percentage of saturated acids, which are saponified with sodium hydroxide. Soft soaps are semifluid soaps made from linseed oil, cotton-seed oil, and fish oils, which are saponified with potassium hydroxide. Tallow used in soapmaking ranges from the cheapest grades, recovered from garbage and used for cheaper soaps, to the best edible grades, used for fine toilet soaps. Tallow alone yields a soap that is too hard and too insoluble to provide satisfactory lathering, and therefore it is usually mixed with coconut oil. Coconut oil alone yields a hard soap that is too insoluble for use in fresh water; it lathers in salt water, however, and is used as marine soap. Transparent soaps usually contain castor oil, high-grade coconut oil, and tallow. A fine toilet soap made of high-grade olive oil is known as castile soap. Shaving soap is a potassium-sodium soft soap, containing stearic acid, which gives a lasting lather. Shaving cream is a paste that is a combination of shaving soap and coconut oil.

FUNCTIONS
Most soaps remove grease and other dirt because some of their components are surface-active agents, or surfactants. Surfactants have a molecular structure that acts as a link between water and the dirt particles, loosening the particles from the underlying fibers or other surfaces to be cleaned. The molecule can perform this function because one end is hydrophilic (attracted to water) and the other is hydrophobic (attracted to substances that are not water soluble). The hydrophilic end is similar in structure to water-soluble salts. The hydrophobic part of the molecule frequently consists of a hydrocarbon chain that is similar to the structure of grease, oil, and many fats. The net result of this peculiar structure permits soap to reduce the surface tension of water (by increasing wetting) and to adhere to and make soluble substances otherwise insoluble in water. Soap powder is a hydrated mixture of soap and sodium carbonate. Powdered soap, which is used in dispensers, is a dry soap that has been pulverized to a fine powder. Liquid soap is a solution of soft potassium soap dissolved in water.

In the late 1960s, because of the increasing concern over the pollution of water resources, the inclusion of harmful chemicals, such as phosphates, in soaps and detergents was actively discouraged. Instead, biodegradable agents that are easily broken down and digested by bacteria came into wide use.