PRODUCTS

E525 (POTASSIUM HYDROXIDE)

E525 (Potassium hydroxide)= KOH

CAS NO: 1310-58-3
EC NUMBER: 215-181-3

E525 (Potassium hydroxide) is an inorganic compound with the formula KOH and is commonly called caustic potash.
Along with sodium hydroxide (NaOH), E525 (Potassium hydroxide) is a prototypical strong base.
E525 (Potassium hydroxide) has many industrial and niche applications, most of which exploit its caustic nature and its reactivity toward acids.
An estimated 700,000 to 800,000 tonnes were produced in 2005. E525 (Potassium hydroxide) is noteworthy as the precursor to most soft and liquid soaps, as well as numerous potassium-containing chemicals.

Properties and structure
E525 (Potassium hydroxide) exhibits high thermal stability. Because of its high stability and relatively low melting point, E525 (Potassium hydroxide) is often melt-cast as pellets or rods, forms that have a low surface area and convenient handling properties.
These pellets become tacky in the air because E525 (Potassium hydroxide) is hygroscopic. Most commercial samples are ca. 90% pure, the remainder being water and carbonates.
Its dissolution in water is strongly exothermic. Concentrated aqueous solutions are sometimes called potassium lyes. Even at high temperatures, solid E525 (Potassium hydroxide) does not dehydrate readily.

Manufacture

Historically, KOH was made by adding potassium carbonate to a strong solution of calcium hydroxide (slaked lime).
The salt metathesis reaction results in precipitation of solid calcium carbonate, leaving E525 (Potassium hydroxide) in solution:

Ca(OH)2 + K2CO3 → CaCO3 + 2 KOH
Filtering off the precipitated calcium carbonate and boiling down the solution gives E525 (Potassium hydroxide) ("calcinated or caustic potash").
This method of producing E525 (Potassium hydroxide) remained dominant until the late 19th century when it was largely replaced by the current method of electrolysis of potassium chloride solutions.
The method is analogous to the manufacture of sodium hydroxide (see chloralkali process):

2 KCl + 2 H2O → 2 KOH + Cl2 + H2
Hydrogen gas forms as a byproduct on the cathode; concurrently, anodic oxidation of the chloride ion takes place, forming chlorine gas as a byproduct.
Separation of the anodic and cathodic spaces in the electrolysis cell is essential for this process.

USE AREAS

KOH and NaOH can be used interchangeably for a number of applications, although in industry, NaOH is preferred because of its lower cost.

The precursor to other potassium compounds
Many potassium salts are prepared by neutralization reactions involving KOH.
The potassium salts of carbonate, cyanide, permanganate, phosphate and various silicates are prepared by treating either the oxides or the acids with KOH.
The high solubility of potassium phosphate is desirable in fertilizers.

Manufacture of soft soaps
The saponification of fats with KOH is used to prepare the corresponding "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 agents than liquefied sodium soaps.

As an electrolyte
Aqueous E525 (Potassium hydroxide) is employed as the electrolyte in alkaline batteries based on nickel-cadmium, nickel-hydrogen, and manganese dioxide-zinc.
E525 (Potassium hydroxide) is preferred over sodium hydroxide because its solutions are more conductive.
The nickel-metal hydride batteries in the Toyota Prius use a mixture of E525 (Potassium hydroxide) and sodium hydroxide.
Nickel–iron batteries also use E525 (Potassium hydroxide) electrolytes.

Food industry
In food products, E525 (Potassium hydroxide) acts as a food thickener, pH control agent and food stabilizer.
The FDA considers E525 (Potassium hydroxide) generally safe as a direct food ingredient when used in accordance with Good Manufacturing Practices.
E525 (Potassium hydroxide) is known in the E number system as E525.

Niche applications
Like sodium hydroxide, E525 (Potassium hydroxide) attracts numerous specialized applications, virtually all of which rely on its properties as a strong chemical base with its consequent ability to degrade many materials.
For example, in a process commonly referred to as "chemical cremation" or "resomation", E525 (Potassium hydroxide) hastens the decomposition of soft tissues, both animal and human, to leave behind only the bones and other hard tissues.
Entomologists wishing to study the fine structure of insect anatomy may use a 10% aqueous solution of E525 (Potassium hydroxide) to apply this process.

In chemical synthesis, the choice between the use of E525 (Potassium hydroxide) and the use of NaOH is guided by the solubility or keeping the quality of the resulting salt.

The corrosive properties of E525 (Potassium hydroxide) make it a useful ingredient in agents and preparations that clean and disinfect surfaces and materials that can themselves resist corrosion by E525 (Potassium hydroxide).

E525 (Potassium hydroxide) is also used for semiconductor chip fabrication (for example anisotropic wet etching).

E525 (Potassium hydroxide) is often the main active ingredient in chemical "cuticle removers" used in manicure treatments.

Because aggressive bases like E525 (Potassium hydroxide) damage the cuticle of the hair shaft, E525 (Potassium hydroxide) is used to chemically assist the removal of hair from animal hides.
The hides are soaked for several hours in a solution of E525 (Potassium hydroxide) and water to prepare them for the unhairing stage of the tanning process.
This same effect is also used to weaken human hair in preparation for shaving.
Preshave products and some shave creams contain E525 (Potassium hydroxide) to force open the hair cuticle and to act as a hygroscopic agent to attract and force water into the hair shaft, causing further damage to the hair.
In this weakened state, the hair is more easily cut by a razor blade.

E525 (Potassium hydroxide) is used to identify some species of fungi.
A 3–5% aqueous solution of E525 (Potassium hydroxide) is applied to the flesh of a mushroom and the researcher notes whether or not the colour of the flesh changes.
Certain species of gilled mushrooms, boletes, polypores, and lichens are identifiable based on this colour-change reaction.

Consumer Uses
E525 (Potassium hydroxide) is used in the following products: washing & cleaning products, cosmetics and personal care products, coating products, pH regulators and water treatment products and perfumes and fragrances. Another release to the environment of E525 (Potassium hydroxide) is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners), outdoor use, indoor use in close systems with the minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters) and outdoor use in close systems with the minimal release (e.g. hydraulic liquids in automotive suspension, lubricants in motor oil and brake fluids).

Article service life
Release to the environment of E525 (Potassium hydroxide) can occur from industrial use: formulation of mixtures and of substances in closed systems with the minimal release.
Another release to the environment of E525 (Potassium hydroxide) is likely to occur from: indoor use in close systems with the minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters) and outdoor use in close systems with the minimal release (e.g. hydraulic liquids in automotive suspension, lubricants in motor oil and brake fluids).
E525 (Potassium hydroxide) can be found in complex articles, with no release intended: electrical batteries and accumulators.

Widespread uses by professional workers
E525 (Potassium hydroxide) is used in the following products: washing & cleaning products.
E525 (Potassium hydroxide) is used in the following areas: mining, scientific research and development, health services, agriculture, forestry and fishing, formulation of mixtures and/or re-packaging, building & construction work, printing and recorded media reproduction and municipal supply (e.g. electricity, steam, gas, water) and sewage treatment.
E525 (Potassium hydroxide) is used for the manufacture of: machinery and vehicles.
Other release to the environment of E525 (Potassium hydroxide) is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners) and outdoor use.

Formulation or re-packing
E525 (Potassium hydroxide) is used in the following products: pH regulators and water treatment products.
Release to the environment of E525 (Potassium hydroxide) can occur from industrial use: formulation of mixtures and of substances in closed systems with minimal release.

Uses at industrial sites
E525 (Potassium hydroxide) is used in the following products: pH regulators and water treatment products.
E525 (Potassium hydroxide) is used in the following areas: mining, scientific research and development and municipal supply (e.g. electricity, steam, gas, water) and sewage treatment.
E525 (Potassium hydroxide) is used for the manufacture of: chemicals and metals.
Release to the environment of E525 (Potassium hydroxide) can occur from industrial use: as processing aid, in processing aids at industrial sites, as an intermediate step in further manufacturing of another substance (use of intermediates), of substances in closed systems with minimal release, in the production of articles and formulation of mixtures.

Manufacture
Release to the environment of E525 (Potassium hydroxide) can occur from industrial use: manufacturing of the substance.

E525 (Potassium hydroxide), also known as lye is an inorganic compound with the chemical formula KOH.
Also commonly referred to as caustic potash, E525 (Potassium hydroxide) is a potent base that is marketed in several forms including pellets, flakes, and powders.
E525 (Potassium hydroxide) is used in various chemical, industrial and manufacturing applications.
E525 (Potassium hydroxide) is also a precursor to other potassium compounds.
E525 (Potassium hydroxide) is used in food to adjust pH, as a stabilizer, and as a thickening agent.
This ingredient has been considered as generally safe as a direct human food ingredient by the FDA, based upon the observance of several good manufacturing practise conditions of use.
In addition to the above uses, E525 (Potassium hydroxide) is also used in making soap, as an electrolyte in alkaline batteries and in electroplating, lithography, and paint and varnish removers.
Liquid drain cleaners contain 25 to 36% of E525 (Potassium hydroxide).
Medically, E525 (Potassium hydroxide) (KOH) is widely used in the wet mount preparation of various clinical specimens for microscopic visualization of fungi and fungal elements in skin, hair, nails, and even vaginal secretions.
Recently, it has been studied for efficacy and tolerability in the treatment of warts.
It was determined that topical E525 (Potassium hydroxide) solution was found to be a safe and effective treatment of plane warts.

USE Categories

Agent for soaking up liquid
General adhesives and binding agents for a variety of uses
Adhesion of molecules to a surface
Relating to agricultural, including the raising and farming of animals and growing of crops
Related to animals (but non-veterinary) e.g., animal husbandry, farming of animals/animal production, raising of animals for food or fur, animal feed, products for household pets
Related to dairy cattle, the operation of dairy facilities, or manufacture of dairy products
Products used on crops, or related to the growing of crops
Used to prevent adhesion
Antifreezing agents, or de-icing products
Anti-incrustator, additional information unknown
Type of pesticide used to destroy or inhibit the growth of disease-causing mechanisms, can be impregnated into clothing
Agent to prevent lime formation
Spray powder used to make air gap between printed sheets of paper
Antishell, no additional information
Products used outside the home (includes outdoor toys such as sandboxes, canopies and shelters, garden statues, outdoor lighting and seating, outdoor power equipment, etc
Aquafarming, or the farming of aquatic organisms
Relatived to the maintenance and repair of automobiles, products for cleaning and caring for automobiles (auto shampoo, polish/wax, undercarriage treatment, brake grease)
Related to food and beverage service activities
Related to the building or repair of ships, pleasure boats, or sporting boats
Bricks or related to bricklaying/masonry
Roofing materials or roofing activities
Materials used in the building process, such as flooring, insulation, caulk, tile, wood, glass, etc.
Flooring materials (carpets, wood, vinyl flooring), or related to flooring such as wax or polish for floors
Related to cement, concrete, or asphalt materials
Wall construction materials, or wall coverings
Includes preservatives used in cosmetics, film, wood preserving agents, foods, etc
Casting agents or molding compounds for plastics, sand, or metals
Catalyst
Modifier used for chemical, when chemical is used in a laboratory
Detergents with wide variety of applications; modifiers included when known
Related to dishwashing products (soaps, rinsing agents, softeners, etc)
Products or chemicals found or used in drycleaning establishments
Products used in an enclosed setting, such as boiler and tank cleansing agents, and drain cleaners
Furniture, or the manufacturing of furniture (can include chairs and tables, and more general furniture such as mattresses, patio furniture, etc.)
Consumer use home grills, for outdoor use, or grill cleaning products
Laundry products (such as cleaning/washing agents), or laundry facilities
Manufacturing of or related to machinery, for production of cement or food, air/spacescraft machinery, electrical machinery, etc
Manufacturing liquid soap; mordant for wood; absorbing CO2; mercerizing cotton; print and varnish removers; electroplating, photoengraving and lithography; printing inks; in analytical chemistry for alkalimetric titrations; in organic synthesis.
Pharmaceutic aid (alkalizer).

Product data and typical properties
Formula: KOH
Molecular weight: 56.1
Specific Gravity (20°C): 1.5 (typical)
Crystallisation temperature: 5°C (approx.)
Appearance: near clear colourless liquid
Assay: % w/w KOH 50.0 ± 1.0
Sodium Hydroxide: % as NaOH <0.8%
Potassium Chloride: % as KCl <0.006%
Potassium Sulphate: % as K2SO4 <0.005%
Iron: % as Fe <0.0005%
Mercury: % as Hg <0.00005%
Heavy Metals: % as Pb <0.0010%

Industry Uses
Agricultural chemicals (non-pesticidal)
Bleaching agents
Cleaning
Corrosion inhibitors and anti-scaling agents
Finishing agents
Food and Beverage Sanitation Chemicals
Functional fluids (open systems)
Intermediates
Ion exchange agents
Lubricants and lubricant additives
Oxidizing/reducing agents
PH Adjuster
Plasticizers
Plating agents and surface treating agents
Process regulators
Processing aids, not otherwise listed
Processing aids, specific to petroleum production
Refining
Repackaged and sold to various customers; enduse unknown
Solids separation agents
Solvents (for cleaning and degreasing)
Solvents (which become part of product formulation or mixture)
Surface active agents
Waste water
chemical distribution

Consumer Uses
Agricultural products (non-pesticidal)
Anti-freeze and de-icing products
Batteries
Building/construction materials not covered elsewhere
C909 the product is used as a cleaner in plating processes. The processes are diverse, examples of final uses are: automotive, machinery, basically all applications of plating.
Cleaning and furnishing care products
Electrical and electronic products
Fabric, textile, and leather products not covered elsewhere
Floor Care Chemicals
Fuels and related products
Laundry and dishwashing products
Lawn and garden care products
Lubricants and greases
Metal processing
Metal products not covered elsewhere
Metal stripping, refining, and waste water
Non-TSCA use
Photographic supplies, film, and photo chemicals
Plastic and rubber products not covered elsewhere
Spent caustic is recycled for use in manufacturing.
Used as raw material in manufacturing.
Water treatment products
chemical distirbution
used in products which are used as cleaners in plating processes, as paint strippers, used as cleaners used in products for a variety of applications for surface treatments, examples of final uses are automotive and machinery.

General Manufacturing Information

Industry Processing Sectors
All other basic inorganic chemical manufacturing
All other basic organic chemical manufacturing
All other chemical product and preparation manufacturing
Computer and electronic product manufacturing
Electrical equipment, appliance, and component manufacturing
Fabricated metal product manufacturing
Food, beverage, and tobacco product manufacturing
Mining (except oil and gas) and support activities
Miscellaneous manufacturing
Nonmetallic mineral product manufacturing (includes clay, glass, cement, concrete, lime, gypsum, and other nonmetallic mineral product manufacturing.
Oil and gas drilling, extraction, and support activities
Paper manufacturing
Pesticide, fertilizer, and other agricultural chemical manufacturing
Petroleum lubricating oil and grease manufacturing
Petroleum refineries
Pharmaceutical and medicine manufacturing
Photographic film paper, plate, and chemical manufacturing
Primary metal manufacturing
Resale of Chemicals
Services
Soap, cleaning compound, and toilet preparation manufacturing
Solar cell manufacturing
Textiles, apparel, and leather manufacturing
Utilities
Wholesale and retail trade
resale of chemicals
sales and services to the marine industry

SYNONYMS:
POTASSIUM HYDROXIDE; 1310-58-3;
Caustic potash;
Potash lye;
Potassium hydrate;
Hydroxyde de potassium;
E525 (Potassium hydroxide) (K(OH));
Potasse caustique; E525 (Potassium hydroxide) solution;
Caustic potash solution;
CHEBI:32035
E525 (Potassium hydroxide), pellets;
KOH;
Cyantek CC 723;
Caswell No. 693;
Potasse caustique [French];
E525 (Potassium hydroxide), 1N solution in water;
E525 (Potassium hydroxide), 1N solution in ethanol;
CCRIS 6569; Hydroxyde de potassium [French];
HSDB 1234; E525 (Potassium hydroxide), pure, 8N solution in water;
Potassio (idrossido di);
E525 (Potassium hydroxide), ca. 85%, extra pure, flakes;
Potassium (hydroxyde de); EINECS 215-181-3; UN1813; UN1814;
E525 (Potassium hydroxide), ca. 85%, ACS reagent, pellets;
E525 (Potassium hydroxide), ca. 85%, for analysis, pellets;
EPA Pesticide Chemical Code 075602;
Kaliumhydroxid;
Aetzkali;
Kalilauge; E525 (Potassium hydroxide) [JAN:NF];

IDENTIFICATION AND USE:
E525 (Potassium hydroxide) (KOH) is commercialized as a solid or as a solution with varying concentrations.
It is used in soap manufacture; drain and pipeline cleaners; bleaching agents; manufacture of potassium carbonate and tetra potassium pyrophosphate, an electrolyte in alkaline storage batteries and some fuel cells, absorbent for carbon dioxide and hydrogen sulfide; dyestuffs; liquid fertilizers; food additive; herbicides; electroplating; mercerizing; and paint removers.

E525 (Potassium hydroxide) is an odorless, white or slightly yellow, flakey or lumpy solid which is often in a water solution.
E525 (Potassium hydroxide) is used in making soap, as an electrolyte in alkaline batteries and in electroplating, lithography, and paint and varnish removers.
Liquid drain cleaners contain 25 to 36% of E525 (Potassium hydroxide).

E525 (Potassium hydroxide)(KOH) is highly basic, forming strongly alkaline solutions in water and other polar solvents.
These solutions are capable of deprotonating many acids, even weak ones.
E525 (Potassium hydroxide) is used to make soft soap, in scrubbing and cleaning operations, as a mordant for woods, in dyes and colorants, and for absorbing carbon dioxide.
Other principle uses of caustic potash are in the preparation of several potassium salts, acid-base titrations, and in orgainic sytheses.

Also, E525 (Potassium hydroxide) is an electrolyte in certain alkaline storage batteries and fuel cells.
E525 (Potassium hydroxide) is used in neutralization reactions to yield potassium salts.
Aqueous E525 (Potassium hydroxide) is employed as the electrolyte in alkaline batteries based on nickel-cadmium and manganese dioxide-zinc.
Alcoholic E525 (Potassium hydroxide) solutions are also used as an effective method for cleaning glassware.
E525 (Potassium hydroxide) works well in the manufacture of biodiesel by catalyzing transesterification of the triglycerides in vegetable oil.

Chemical Properties
Pure E525 (Potassium hydroxide) is a solid at room temperature, though E525 (Potassium hydroxide) is often sold as a liquid.
E525 (Potassium hydroxide) is a strong alkaline substance that dissociates completely in water into the potassium ion (K+) and hydroxide ion (OH-).
The dissolution in water generates heat, so a vigorous reaction can occur when E525 (Potassium hydroxide) is added to water.
The vapor pressure of the substance is very low and the melting point is high. E525 (Potassium hydroxide) solutions attack aluminium and its alloys under formation of hydrogen gas.
It can be neutralised with acids (e.g. hydrochloric acid) giving the corresponding potassium salts of the acids, which are usually pH neutral and non-corrosive.

Uses
E525 (Potassium hydroxide) has many different functions and uses.
It is primarily used as an intermediate in industrial manufacturing processes, such as the manufacture of fertilisers, potassium carbonate or other potassium salts and organic chemicals.
It is also used in the manufacture of detergents and in alkaline batteries.
Small-scale uses include drain cleaning products, paint removers and degreasing agents.
manufacture of liquid soap;
mordant for wood;
absorbing CO2;
mercerizing cotton;
paint and varnish removers;
electroplating, photoengraving and lithography;
printing inks;
in analytical chemistry and in organic syntheses.
Pharmaceutic aid (alkalizer).

E525 (Potassium hydroxide) is used in making liquidsoap and potassium salts, in electroplatingand lithography, in printing inks, as a mordantfor wood, and finds wide applications in organic syntheses and chemical analyses.
E525 (Potassium hydroxide) is used as an emulsifier in lotions and as an alkali in liquid soaps, protective creams, and shaving preparations.
Depending on the concentration used, E525 (Potassium hydroxide) can be highly irritating to the skin and/or cause a burning sensation.
E525 (Potassium hydroxide) is a water-soluble food additive and bleaching agent.
Upon exposure to air E525 (Potassium hydroxide) readily absorbs carbon dioxide and moisture and deliquesces.
E525 (Potassium hydroxide) is used to destroy the bitter chemical constituents in olives that will be used as black olives.

E525 (Potassium hydroxide) solution (KOH aqueous) is a colourless inorganic liquid that acts as a strong base (alkali).
E525 (Potassium hydroxide) solution is also known as caustic potash or potash lye and has many different applications.
During the E525 (Potassium hydroxide) liquid production process, chlorine and hydrogen are formed as co-products.

In addition to the above uses, E525 (Potassium hydroxide) is also used in making soap, as an electrolyte in alkaline batteries and in electroplating, lithography, and paint and varnish removers.
Liquid drain cleaners contain 25 to 36% of E525 (Potassium hydroxide).

Recently, E525 (Potassium hydroxide) has been studied for efficacy and tolerability in the treatment of warts.
E525 (Potassium hydroxide) was determined that topical E525 (Potassium hydroxide), also known as lye is an inorganic compound with the chemical formula KOH.
Also commonly referred to as caustic potash, E525 (Potassium hydroxide) is a potent base that is marketed in several forms including pellets, flakes, and powders.
E525 (Potassium hydroxide) is used in various chemical, industrial and manufacturing applications.
E525 (Potassium hydroxide) is also a precursor to other potassium compounds.
E525 (Potassium hydroxide) is used in food to adjust pH, as a stabilizer, and as a thickening agent.
This ingredient has been considered as generally safe as a direct human food ingredient by the FDA, based upon the observance of several good manufacturing practise conditions of use.

Recently, E525 (Potassium hydroxide) has been studied for efficacy and tolerability in the treatment of warts.
E525 (Potassium hydroxide) was determined that topical KOH solution was found to be a safe and effective treatment of plane warts solution was found to be a safe and effective treatment of plane warts
E525 (Potassium hydroxide) is a chemical that comes as a powder, flakes, or pellets.
It is commonly known as lye or potash. E525 (Potassium hydroxide) is a caustic chemical.

IUPAC NAMES:
Caustic potasch
Caustic potash
caustic potash
caustic potash
Caustic potash, Potassium hydrate
Hidroxido de potasio
hydroxid draselný
KOH
Reaction mass of 57-13-6 and 7789-20-0
UPV7