PURITY OF SOAP.

Hauraki Plains Gazette, Volume XXXVIII, Issue 5094, 28 February 1927, Page 3

PURITY OF SOAP.

REGULATIONS APPROVED.

VARIOUS PROPERTIES GOVERNED,

Following numerous regulations which have been issued controlling the preparation, manufacture, ami sale o’f foods, sale df fuels, and many domestic articles, the Department of Health is about te bring’ into operation new regulations governing the manufacture and sale of soap. They have been approved by Cabinet, and are to be gazetted shortly.

Briefly soap 'for human use may only be sold in three grades, and the use c-f "purest,” “highest grade,” “first quality,” and similar descriptions may only be used on the labels or impressed on soaps of the first grade, and names may not be used unless the material so mentioned is used in the manufacture of that particular soap.

An explanatory statement on the action of soap and washing,compounds has been made by the department* Soap is a chemical compound in which an alkali, such as caustic soda or caustic potash, is combined with a fatty acid, such as tallow or resin acid. Suds are an emulsion of air in the solution, and .their value in washing is considerable, creating a cushion of air,, which lubricates and reduces friction, carrying oxygen within the cloth to whiten the fibres, and removing dirt by agitation and buoyancy. Sait water inteifferes with .the normal colloidal action of soap solutions. The commonest adjunct to soap for general laundry purposes is carbonate of soda, commonly called washing soda. Practically all soda adjuncts have some destructive action on fab-

• Home-made soaps are often considered to be better than bought soaps, but this is usually due to the; presence of rfee caustic which they carry, there being more caustic added in the mixing or making o'f the soap than is necessary to take up all. the Tat used. Caustic is, no doubt, a great cleanser, but it is also a great destroyer. Borax has been used for wool and silk washing, and has slight bleaching action on textiles, but its detergent and cleansing qualities are of doubtful quality.

Silicate of soda is the substance known as waterglass, commonly used for preserving eggs. Originally its value lay in the fact that it enabled more water to be added to bars of soap, which led to the commonplace that’the soapmaker’s art was to make water’ “stand on end.” It has a, detergent value of some merit, yields a reasonable amount of active alkali, assists in the removal of dirt, and has less tendency to cause fabrics to turn a bad colour than caustic or carbonate. . Many of the better class soaps sold for laundry and household purposes are used for toilet purposes, hence the regulations have been framed to include all such soaps. Provision is made for the limitation or silicate of carbonate and caustic, especially in toilet soaps, which contain more fatty acids and are richer soaps. Castile, barilla, shaving, and other soap preparations are dealt with to ensure the highest degree o,f purity, freedom from irritants* and truthful labelling.