Potassium Hydroxide

Other Classes -> Bases

Corrosives

Cosmetic ingredients (Potassium Hydroxide) -> CIR (Cosmetic Ingredient Review)

Buffering

Strongly alkaline (1 % solution)

pH = 13.5 (0.1 Molar aq soln)

nuclear quadrupole moment

Odorless

FORMULATION AID, FUMIGANT, PH CONTROL AGENT, PROCESSING AID, STABILIZER OR THICKENER, WASHING OR SURFACE REMOVAL AGENT -> FDA Substance added to food

1.45 to 1.50 at 68 °F (USCG, 1999)

2.04 at 59 °F (USCG, 1999) - Denser than water; will sink

2.044 g/cu cm

Colorless, strongly basic, soapy, caustic liquid whose density depends on the concentration (g/cu cm at wt%): 1.092 at 10; 1.188 at 29; a.291 at 30; a.395 at 40; 1.514 at 50 /Aqueous potassium hydroxide/

2.04 g/cm³

2.04

White or colorless, orthorhombic, deliquescent pieces, lumps, or sticks having crystalline fracture

White or slightly yellow lumps, rods, pellets

White rhombic crystals

107 g/100 cc at 59 °F (NTP, 1992)

Soluble

Very soluble in water. Freely soluble in ethanol

Solubility in water, 121 g/100 g water at 25 °C

Solubility in water (g KOH/100 g H2O): 97 at 0 °C; 103 at 10 °C; 112 at 20 °C; 126 at 30 °C; 178 at 100 °C

Soluble in 0.9 part water, about 0.6 part boiling water

Corrosive

Pharmaceuticals -> UK Veterinary Medicines Directorate List

greater than 266 °F at 760 mmHg (USCG, 1999)

2408 °F at 760 mmHg (NTP, 1992)

1,320

1327 °C

1324 °C

2408 °F

Danger

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P260, P264, P270, P280, P301+P317, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P321, P330, P363, P405, and P501 (click each P-code to see the statement)

This chemical does not meet GHS hazard criteria for < 0.1% (3 of 4709) of reports.

Danger

H290 (20.9%): May be corrosive to metals [Warning Corrosive to Metals]

Chemical: Potassium hydroxide (K(OH))

Regulation (EC) No 178/2002 (amended)

Potassium hydroxide (K(OH)) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Potassium hydroxide (K(OH)) are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Cease Manufacture Update: 01-05-2018 https://echa.europa.eu/registration-dossier/-/registered-dossier/24316

Potassium hydroxide: HSNO Approval: HSR001546 Approved with controls

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

IMAP assessments - Potassium hydroxide: Human health tier II assessment

Corrosive

Corrosive

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

· Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.

· Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.

· Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.

· Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.

When wet, attacks metals such as aluminum, tin, lead & zinc to produce flammable hydrogen gas.

Causes severe burns of eyes, skin, and mucous membranes. (USCG, 1999)

Causes severe burns of eyes, skin, and mucous membranes. (USCG, 1999)

· TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.

· TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.

· TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.

· TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.

Liquid causes second or third degree burns after short contact. [CHRIS] Potassium hydroxide 30-70% is highly corrosive to skin; [Quick CPC] A corrosive substance that can cause pulmonary edema; [ICSC] See Sodium hydroxicde.

1813 154

1814 154

1813 154

1814 154

1813 154(dry, solid)

1814 154(solution)

Substance added directly to human food affirmed as generally recognized as safe (GRAS).

Potassium hydroxide used as a general purpose food additive in animal drugs, feeds, and related products is generally recognized as safe when used in accordance with good manufacturing or feeding practice.

Bases, Strong

Bases, Strong

Symbol: C; R: 22-35; S: (1/2)-26-36/37/39-45

UN Hazard Class: 8; UN Pack Group: II

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

In case of fire in the surroundings, use appropriate extinguishing media.

Fresh air, rest. Refer immediately for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower for at least 15 minutes. Refer immediately for medical attention.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Do NOT induce vomiting. If within a few minutes after ingestion, one small glass of water may be given to drink. Refer immediately for medical attention.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

(Act quickly])

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

General First Aid:

General First Aid:

General First Aid:

General First Aid:

Separated from food and feedstuffs, strong acids and metals. Store only in original container. Dry. Well closed. Store in an area without drain or sewer access.

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear positive pressure self-contained breathing apparatus (SCBA).

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Wear self-contained breathing appartus for firefighting if necessary.

Keep container tightly closed in a dry and well-ventilated place. Absorbs carbon dioxide (CO2) form air. Air sensitive. Strongly hygroscopic. Storage class (TRGS 510): Non-combustible, corrosive hazardous materials.

Personal precautions, protective equipment and emergency procedures: Wear respiratory protection. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust...

Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.

Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Neutralization & discharge to sewer: Carefully dissolve in water and neutralize with dilute acetic acid. Flush to sewer with lots of water, regulations permitting or dispose of through a licensed contractor. Consider use of waste caustic for neutralizing plant acid wastes.

Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Sweep spilled substance into covered plastic containers. Carefully collect remainder. Then store and dispose of according to local regulations.

Eyes, skin, respiratory system

LC50; Species: Gambusia affinis (mosquito fish); Concentration: 80 mg/L for 96 hr /Conditions of bioassay not specified in source examined/

TLm Mosquito fish 80 ppm/24 hr fresh water. /Conditions of bioassay not specified/

Dermatotoxin - Skin burns.

Serious local effects by all routes of exposure.

inhalation, ingestion, skin and/or eye contact

The CIR Expert Panel concluded that ... Potassium Hydroxide is safe in hair straighteners and depilatories under conditions of recommended use; users should minimize skin contact.  These ingredients are safe for all other present practices of use and concentration described in this safety assessment when formulated to be nonirritating.

Safe for use in cosmetics, with qualifications

IDENTIFICATION AND USE: Potassium hydroxide (KOH) is commercialized as a solid or as solutions with varying concentrations. It is used in soap manufacture; drain and pipeline cleaners; bleaching agents; manufacture of potassium carbonate and tetrapotassium 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. HUMAN EXPOSURE AND TOXICITY: Potassium hydroxide causes direct local effects on the skin, eyes and gastrointestinal tract after direct exposure. If KOH aerosols/mists occur, they will cause direct local effects on respiratory tract. Solutions with concentrations higher than 2% are corrosive, while concentrations of about 0.5 to about 2.0 % are irritating. The irritant effects are reported as coughing, wheezing, conjunctivitis, tearing, and irritation. Children may be accidentally exposed to commercial cleaning products. In a retrospective clinical study with 168 children after alkaline substance ingestion, 9 children (5.3%) developed gastric outlet obstruction. The fatal complications from an alkaline battery foreign body (containing potassium hydroxide 45%) in the esophagus of a 2.5 year old male, resulting in corrosive burns of the esophagus, necrosis, perforation, communication between the esophagus and the trachea and subsequent death, is reported. A total of 23 burns of the eye due to NaOH or KOH were admitted to the eye clinic of the RWTH Aachen in Germany from 1985 to 1992. In 17 cases the accident happened during work, while 6 cases occurred at home using NaOH/KOH as drain cleaner. The alkali burns were of special interest because of the rapid and deep penetration of alkali into the ocular tissues. A 4-year old boy who had a button battery lodged in his nose for approx. 24 hrs had local tissue corrosion, with a small perforation, caused presumably by the 25% KOH electrolyte. An epidemiological study about potash mining workers failed to correlate the exposure to potash to a number of diseases evaluated, including lung cancer. However, there is also a strong association between lye stricture of the esophagus and esophageal squamous cell carcinoma, with a long latent period of eventually several decades. ANIMAL STUDIES: In an acute toxicity study for KOH, the LD50 (intubation) of male rats was 365 mg/kg. Hemorrhaging of the stomach and intestine and adhesions of abdominal organs (stomach, pancreas, spleen, liver and small intestine) were seen following administration of both lethal and sub-lethal doses. Surviving animals showed evidence of hyper excitability, followed by apathy and weakness throughout the 14-day post-exposure period. Other clinical signs were increased respiration rate, ruffled fur, eye closing and bloody nasal exudate. All deaths occurred within 72 hours of dosing. KOH has a moderate acute oral toxicity, which is essentially due to its corrosivity. The observed systemic effects could be regarded as secondary effects. Draize skin tests in rabbits, with gauze covering and application of 0.1 mL during 24 hours, qualified a 5% KOH solution as mildly irritating on intact skin and highly irritating on abraded skin. A 10% KOH solution was qualified as corrosive on both intact and abraded skin as the result of a Draize occlusive test on rabbits with 4 hours exposure to 0.5 mL of the solution. The results of an Ames assay study with Salmonella typhimurium TA 97 and TA 102, with and without metabolic activation and up to 1 mg KOH/plate, were negative. The clastogenic activity of KOH was studied in an in vitro chromosomal aberration test using Chinese hamster ovary (CHO) K1 cells. No clastogenic activity was found at KOH concentrations of 0, 8 and 12 mM, which corresponded with initial pH values of 7.3, 9.8 and 10.4, respectively. A long-term study (reliability 3) of 25-46 weeks, consisting of painting 3-6% KOH solutions on mouse skin, has been performed. The results were ca. 15% occurrence of cancer at the application site. An old long-term study (reliability 3) of 25-46 weeks, consisting of painting 3-6% KOH solutions on mouse skin, has been performed. The results were 15% occurrence of cancer at the application site. Doses of 2.35-235 mg/kg bw/day in mice and 3.1-310 mg/kg bw/day in rats were administered to groups of 21-24 animals by single daily oral intubation. Body weights were recorded during 17 days for mice, with a post exposure period of 2 days and during 20 days for rats, with a post exposure period of 5 days. No significant effects were observed on mice and rat's survival and reproductive organs, or on offspring survival, weight, sex ratio and congenital defects.

Cough. Sore throat. Burning sensation. Shortness of breath.

Redness. Pain. Serious skin burns. Blisters.

Redness. Pain. Blurred vision. Severe burns.

Abdominal pain. Burns in mouth and throat. Burning sensation in the throat and chest. Nausea. Vomiting. Shock or collapse.

irritation eyes, skin, respiratory system; cough, sneezing; eye, skin burns; vomiting, diarrhea

This substance may be hazardous to the environment. Special attention should be given to aquatic organisms.

/HUMAN EXPOSURE STUDIES/ Potassium hydroxide (KOH) is a strong alkali that has long been known to digest proteins, lipids, and most other epithelial debris of skin scrapings to identify fungal infections. To our knowledge, KOH has never been used for the treatment of molluscum contagiosum (MC). We evaluated 35 children with MC for the clinical effectiveness of treatment with topical 10% KOH aqueous solution. The solution was applied by the parents of affected children, twice daily, on each MC lesion. The therapy was continued until all lesions underwent inflammation and superficial ulceration. Thirty-two of 35 patients achieved complete clinical cure after a mean treatment period of 30 days. Three children discontinued treatment: two reported severe stinging of the lesions and refused further applications; the other, with giant MC lesions, developed a secondary infection with prolonged treatment. Therapy with KOH was found to be effective and safe in the treatment of MC in children.

/SIGNS AND SYMPTOMS/ Acute poisoning: ... ingestion of alkali is followed by severe pain, vomiting, diarrhea, & collapse. The vomitus contains blood and desquamated mucosal lining. If death does not occur in the first 24 hours, the patient may improve for 2-4 days and then have a sudden onset of severe abdominal pain, boardlike abdominal rigidity, and rapid fall of blood pressure indicating delayed gastric or esophageal perforation. ... Esophageal stricture can occur weeks, months, or even years later to make swallowing difficult. Carcinoma is a risk in later life. /Alkalies/

/SIGNS AND SYMPTOMS/ Acute poisoning: ... alkalies penetrate skin slowly. Extent of damage ... depends on duration of contact. ... Chronic poisoning: (from skin contact) a chronic dermatitis may follow repeated contact with alkalies. /Alkalies/

/SIGNS AND SYMPTOMS/ There are great many accounts of accidental and suicidal ingestion of the sodium and potassium hydroxides... Death results from shock, perforation of the esophagus, aspiration from the esophagus into the trachea, pneumonitis, mediatinitis, or inanition and infection.

For more Human Toxicity Excerpts (Complete) data for POTASSIUM HYDROXIDE (31 total), please visit the HSDB record page.

/LABORATORY ANIMALS: Acute Exposure/ There are no data from which to derive a dose-effect or dose-response relationship for occupational exposure to potassium hydroxide. Eye irritation has been studied in rabbits. A 5% solution was corrosive to the eye, and a 0.1% solution had no effect.

/LABORATORY ANIMALS: Acute Exposure/ In a Draize rabbit test (reliability 3) with gauze covering and application of 0.5 mL of KOH solutions during 4 hours, the 1% solution was not corrosive, whereas the 2% solution was corrosive. There was no post-exposure assessment of the lesion.

/LABORATORY ANIMALS: Acute Exposure/ A 10% KOH solution was qualified as corrosive on both intact and abraded skin as the result of a Draize occlusive test on rabbits with 4 hours exposure to 0.5 ml of the solution. The results with guinea pigs were similar.

/LABORATORY ANIMALS: Acute Exposure/ In a classical rabbit Draize test with gauze covering, application of 0.5 mL of KOH 5% during 4 hours gave a PDII (primary dermal irritation indices) result of 4.8 (moderately irritating). A 10% solution was severely irritating. With 19 mm diameter Hill Top Chamber pad covering during 1 or 4 hours and 0.2 mL applied, the 5 and 10% KOH solutions were qualified as severely irritating.

For more Non-Human Toxicity Excerpts (Complete) data for POTASSIUM HYDROXIDE (10 total), please visit the HSDB record page.

According to the 2012 TSCA Inventory Update Reporting data, 38 reporting facilities estimate the number of persons reasonably likely to be exposed in manufacturing, processing, or use of potassium hydroxide in the United States may be as low as <10 workers and as high as 9999 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 1,966,611 (800,041 of these were female) were potentially exposed to potassium hydroxide in the US(1). Occupational exposure to potassium hydroxide may occur through inhalation and dermal contact with this compound at workplaces where potassium hydroxide is produced or used(SRC).

Immediate first aid: Remove patient from contact with the material. Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Inorganic Bases/Alkaline Corrosives and Related Compounds/

Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 6 to 12 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patent can swallow, has a strong gag reflex, and does not drool ... . Do not attempt to neutralize. Cover skin burns with dry sterile dressings after decontamination ... . /Inorganic Bases/Alkaline Corrosives and Related Compounds/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Early intubation, at the first signs of upper airway obstruction, may be necessary. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Inorganic Bases/Alkaline Corrosives and Related Compounds/

LD50 Rat oral 363 mg/kg bw/day

LD50 Rat oral 273 mg/kg bw/day

LD50 Rat oral 1230 mg/kg bw/day

Substance added directly to human food affirmed as generally recognized as safe (GRAS).

Potassium hydroxide used as a general purpose food additive in animal drugs, feeds, and related products is generally recognized as safe when used in accordance with good manufacturing or feeding practice.

Residues of potassium hydroxide are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest. Use: neutralizer.

Residues of potassium hydroxide are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to animals. Use: neutralizer. Limit: Meeting Food Chemicals, Codex specifications.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer safety standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Potassium hydroxide is found on List D. Case No: 4065; Pesticide type: fungicide, herbicide, antimicrobial; Case Status: RED Approved 09/92; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Potassium hydroxide; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1000 lb or 454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

Potassium hydroxide is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.

The corrosiveness of potassium hydroxide renders it a very useful agent in the decomposition/removal soft tissue and hair removal. It is incorporated into some nail products, shaving creams, and soaps.

The exact mechanism of action of KOH is not known but the speculated one is that topical application of KOH digests keratin, and induces inflammation. The mechanism of skin injury by alkali substances such as potassium hydroxide is by the saponification of fat, causing fatty tissue to lose its function with increased damage due to a heat reaction. Extraction of water from cells occurs due to the hygroscopic (absorbent) nature of alkali. Dissolution of proteins also occurs, allowing for deeper penetration of OH- ions and resulting in various chemical reactions. The alkali penetrates the skin quickly, saponifies plasma membranes, denatures collagen proteins, and leads to vascular thromboses in the conjunctiva and other parts of the eye. The resulting corneal burns include scarring and opacification of the cornea with resulting in vision loss, corneal neovascularization, ulcer formation, and perforation. Other consequences of untreated or very severe alkali burns include epithelial erosions, secondary glaucoma, and causes the destruction of conjunctival mucus cells, causing dry eyes, trichiasis (misdirected eyelash hairs), and other ocular conditions. In the gastrointestinal tract, after oral ingestion, burns may result. The mechanism of injury is liquefactive necrosis. The thrombosis of gastrointestinal blood vessels also contributes to tissue damage. When the alkali enters the stomach, gastric acid may neutralize the strong base, which can limit the extent of the injury. Perforation of the stomach can sometimes occur with peritonitis and caustic injury to the surrounding organs including the colon, pancreas, liver, and spleen.

The mechanism of injury by alkali skin burns is by saponification of fat, which causes fatty tissue to lose its function with increased damage due to heat reaction; extraction of considerable water from cells due to the hygroscopic nature of alkali; and dissolution of proteins, permitting so deeper penetration of OH- ions and further chemical reactions.

A systemic (non-acute) oral intoxication by KOH is not expected. Regarding the potassium toxicity, the LD50 value in rats of KCl, 3.020 g/kg bw/day is much higher than that of KOH, in the range of 0.273 - 0.365 - 1.230 g KOH/kg bw/day. This demonstrates that the acute toxicity of KOH is probably due to the corrosivity caused by the OH- ion (pH value), and less to systemic toxic effects of the K+ ion. Under non-irritating conditions, the potassium doses are much lower than those used in acute toxicity studies, and therefore not relevant from the point of view of the systemic toxicity of potassium. Furthermore, the uptake of potassium, via exposure to potassium hydroxide, is much less than the oral uptake with therapeutic doses of KCl for treating potassium deficiency, of up to 10 g/day. Moreover, the oral uptake of potassium from food, from natural origin or from food additives, is likely to be also much higher.

KOH in aqueous solution is entirely dissociated into K+ and OH- ions. Due to the neutralization of OH- by gastric HCl and the quick and efficient blood pH regulation mechanisms (buffer capacity of extra cellular body fluids, respiratory and renal compensation mechanisms), an alkalosis due to the OH- ions after KOH oral dosage in non-irritating conditions is prevented.

KOH in aqueous solutions is completely dissociated into K+ and OH- ions. Due to the neutralization of OH- by gastric HCl and the quick and efficient blood pH regulation mechanisms (buffer capacity of extra cellular body fluids, respiratory and renal compensation mechanisms), an alkalosis due to the OH- ions after KOH oral dosage in non-irritating conditions is prevented.

...In every case, it should be realised that aerosols of KOH are not stable. They are rapidly transformed due to an uptake of carbon dioxide from the atmosphere resulting in the formation of potassium bicarbonate and potassium carbonate. Cooper et al. (1979) reported that the transformation of respirable NaOH aerosols into carbonate aerosols could occur in seconds...

Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant &amp; Hackh&apos;s Chemical Dictionary, 5th ed, p301, p499)

KOH in aqueous solutions completely dissociates into K+ and OH- ions. Because of the neutralization of OH- by gastric HCl and the rapid blood pH regulation action (buffer capacity of extracellular body fluids, respiratory and renal compensation mechanisms), an alkalosis due to the OH- ions after KOH oral dosage in non-irritating conditions is thus prevented. The uptake of potassium, in potassium hydroxide form, is much less than the oral uptake with therapeutic doses of KCl for treating potassium deficiency, of up to 10 g/day. Furthermore, the oral uptake of potassium from food/natural sources or from food additives is likely to be also much higher.

Interesting observations are also that alkalosis promotes renal excretion of K+, and that, for preventing hyperkalemia, extra cellular potassium is taken up by cells in exchange for hydrogen ions (Saxena, 1989). In other words, these compensating effects of K+ and OH- would attenuate the systemic effect of KOH.

...It can also be stated that the substance will neither reach the foetus nor reach male and female reproductive organs in effective toxic concentrations. Therefore, no risk for reproductive toxicity is expected.

Under normal handling and use conditions (non-irritating) neither the concentration of potassium in the blood nor the pH of the blood will be increased above normal limits and therefore KOH is not expected to cause systemically toxic levels in the blood. The renal excretion of K+ can be elevated and the OH- ion is neutralised by the bicarbonate buffer system in the blood...

Alkalies penetrate skin slowly. /Alkalies/

Ammonium hydroxide penetrates fastest, followed by sodium hydroxide, potassium hydroxide, and finally calcium hydroxide.

CIR ingredient: Potassium Hydroxide

Used to make liquid soaps; it is also used in paint, varnish removers, and drain cleaners; it is used in electroplating, photoengraving, and lithography. [ACGIH] Used as a wet etchant in semiconductor manufacturing at standard concentrations of 50% or 10%; [CSH, p. 46]

Acid and Alkali Cleaning of Metals [Category: Clean]

Lithography printing [Category: Hobbies]

For potassium hydroxide (USEPA/OPP Pesticide Code: 075602) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

/Potential/ impurities: sodium oxide, sodium carbonate, sodium chloride, sodium chlorate, ferrous oxide, mercury, sodium sulfate, silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, manganese, nickel, and copper.

(1972) 6.36X10+9 GRAMS

(1975) 8.35X10+9 GRAMS

(1984) 8.99X10+9 g.

(1994) 60,000 tons

(1972) 1.45X10+9 GRAMS

(1975) 6.53X10+9 GRAMS

(1984) 1.60X10+10 g.

(1994) 55,000 tons

2023: 1,000,000,000 - <2,500,000,000 lb

(1972) 1.54X10+11 GRAMS

(1975) 1.91X10+11 GRAMS

(1984) 2.25X10+11 G. /88 to 92% POTASSIUM HYDROXIDE - LIQUID/

Demand: 1986: 245,000 tons; 1987: 250,000 tons; 1991 /projected/: 270,000 tons. (Includes imports; 16,000 tons were imported in 1986.)

For more U.S. Production (Complete) data for POTASSIUM HYDROXIDE (8 total), please visit the HSDB record page.

29% AS A CHEM INT FOR POTASSIUM CARBONATE; 19% AS A CHEM INT FOR SOAPS; 19% AS A CHEM INT FOR TETRAPOTASSIUM PYROPHOSPHATE; 10% AS A CHEM INT FOR OTHER INORG POTASSIUM CHEMICALS; 8% AS A CHEM INT FOR LIQUID FERTILIZERS; 5% IN MFR OF DYESTUFFS; 4% IN MFR OF HERBICIDES; 6% FOR MISC USES (1975)

Potassium Carbonate, 25%; Liquid Fertilizers, 15%; Soap, 10%; Potassium Phosphates, 9%; Synthetic Rubber, 5%; Pesticides, 3%; Potassium Permanganate, 2%; Exports, 5%; Other Chemicals and Misc uses, 26% (1984)

Potassium carbonate, 25%; potassium phosphates (including TKPP), 10%; liquid fertilizers, 8%; soaps, 7%; potassium chemicals (including potassium silicate, permaganate and cyanide), 30%; miscellaneous (including oil and gas, metal treatment, batteries and water treatment), 18%; exports, 2%.

Potassium chemicals (including potassium acetate, cyanide, permanganate and silicate), 35%; potassium carbonate, 25%; liquid fertilizer, 12%; soaps, 12%; potassium phosphates (including tetrapotassium pyrophosphate), 7%, miscellaneous, 9%.

Solvent

Ion exchange agent

Potassium hydroxide is produced industrially by the electrolysis of potassium chloride.

Largely water-free, ca. 90-95% potassium hydroxide (caustic potash) is obtained by evaporating potassium hydroxide solution. The residual content of 5-10% H2O is bound as a monohydrate.

Grades: Commercial, ground, flake, fused (88-92%), purified by alcohol (sticks, lumps and drops), reagent, highest purity, United States Pharmacopeia, liquid (45%), FCC.

Available as 50%-Rayon, 50%-Commercial, 73%-Commercial, and Flake.

Marketed as dehydrated solid (90-92% potassium hydroxide) and as a liquor (45-50% potassium hydroxide).

2 Liquid grades sold: rayon and commercial.

POTASSIUM HYDROXIDE ... CONTAINS NOT LESS THAN 85.0% OF TOTAL ALKALI, CALCULATED AS POTASSIUM HYDROXIDE ... & INCL NOT MORE THAN 3.5% OF POTASSIUM CARBONATE ...

Information on 291 consumer products that contain Potassium hydroxide in the following categories is provided:

EPA Safer Chemical Functional Use Classes -> Processing Aids and Additives

Safer Chemical Classes -> Green circle - The chemical has been verified to be of low concern

Food additives

Food Additives -> ACIDITY_REGULATOR -> JECFA Functional Classes

Food Additives -> ACIDITY_REGULATOR -> JECFA Functional Classes

Cosmetics -> Buffering