Potassium Hydroxide, also known as caustic potash, is a strong alkali. It is usually sold as translucent flakes or pellets, which become tacky when exposed to air because it is hygroscopic. Consequently, it characteristically contains varying amounts of water, as well as carbonates. Its dissolution in water is strongly exothermic, meaning the process gives off significant heat. The concentrated aqueous solution of potassium hydroxide is called potassium lye or potash lye.
Potassium hydroxide is used in making lake pigments, to saponify (form soap) oil, wax or resin, such as rosinate for varnishes, and to hydrolyze casein to make tempera paint. It can be substituted with sodium hydroxide, another strong alkali.
Solubility Approximately 121 g of potassium hydroxide will dissolve in 100 mL of water at room temperature (compared with 100 g of sodium hydroxide in the same volume). Lower alcohols such as methanol, ethanol, and propanols are also excellent solvents. The solubility in ethanol is about 40 g potassium hydroxide in 100 mL ethyl alcohol.
Saponification The saponification of fats with potassium hydroxide is used to prepare "potassium soaps," which are softer than the more common sodium hydroxide-derived soaps. Because of their softness and greater solubility, potassium soaps require less water to liquefy, and can thus contain more cleaning agent than liquefied sodium soaps. < br/>
Storage Keep in a tightly closed container, stored in a cool, dry, ventilated area. Protect against physical damage. Isolate from incompatible substances. Protect from moisture. Addition to water releases heat which can result in violent boiling and spattering. Always add slowly and in small amounts. Never use hot water. Containers of this material may be hazardous when empty since they retain product residues (dust, solids); observe all warnings and precautions listed for the product.
Safe Handling Wear impervious protective clothing, including boots, gloves, apron or coveralls, as appropriate, to prevent skin contact. Use chemical safety goggles and/or full face shield where dusting or splashing of solutions is possible. Refer to Material Safety Data Sheet.
DANGER! CORROSIVE. CAUSES SEVERE BURNS TO SKIN, EYES, RESPIRATORY TRACT, AND GASTROINTESTINAL TRACT. MATERIAL IS EXTREMELY DESTRUCTIVE TO ALL BODY TISSUES. MAY BE FATAL IF SWALLOWED. HARMFUL IF INHALED.
Environmental Hazards This product is toxic to aquatic organisms, and may cause long-term adverse effects in the aquatic environment. If product is spilled, comply with Federal, State and local regulations on reporting spills. Refer to Material Safety Sheet and labels for further details.
Natural Pigments is a limited liability company based in Willits, California. We manufacture and distribute rare and hard-to-find materials for fine artists and decorators. We specialize in supplying artists' materials that were used in historical painting since pre-historic times up to and including the nineteenth century.
We constantly search for materials and products of the finest quality so that we can bring them direct to you from the source. To do so, we travel the world to find materials specifically for use by professional artists and decorators. We obtain minerals from mines in Afghanistan, Chile, Russia, Ukraine and Uzbekistan, to name a few places, processing these into natural pigments. We purchase resins, gums and plants from India, Kenya and Malaysia to make natural varnishes and painting mediums.
Our mission is to provide the largest variety of natural pigments, paints and other professional artists' supplies, enabling us to bring you a selection that makes shopping for rare and hard-to-find art materials easy. Our objective is to promote the education and use of these materials among artists by providing detailed information for their employment in encaustic, fresco, oil, watercolor and tempera painting.
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