Potassium hydroxide, solution appears as an clear aqueous solution. Corrosive to metals and tissue. Noncombustible. Used in chemical manufacturing, petroleum refining, cleaning compounds.
颜色/状态：
White or colorless, orthorhombic, deliquescent pieces, lumps, or sticks having crystalline fracture
气味：
Odorless
蒸汽压力：
1 MM HG @ 714 °C
自燃温度：
Not flammable (USCG, 1999)
分解：
When heated to decomposition it emits toxic fumes of K2O.
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...
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.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
暴露途径
所有暴露途径都会产生严重的局部影响。
Serious local effects by all routes of exposure.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
毒理性
暴露途径
吸入，摄入，皮肤和/或眼睛接触
inhalation, ingestion, skin and/or eye contact
来源:The National Institute for Occupational Safety and Health (NIOSH)
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...
The invention relates to compounds of formula
wherein
R1 is a 5 or 6 membered heteroaryl group, containing 1 to 3 heteroatoms, selected from N, O or S, and which groups are optionally substituted by one or two substituents, which are lower alkyl, —(CH2)nOH, halogen or lower alkoxy, and wherein the heteroaryl groups may be optionally linked to the pyrazole ring via an alkylene or alkenyl group, or is
phenyl, optionally substituted by one or two substituents being lower alkyl, hydroxy-lower alkyl, halogen, hydroxy or lower alkoxy or is
—O(CH2)n,phenyl, benzofuryl, indolyl or benzothiophenyl, or is
—S-lower alkyl;
R2 and R4 are independently from each other hydrogen, cyano or —S(O)2-phenyl;
R3 is hydrogen, halogen or is
a 5 or 6 membered heteroaryl group, containing 1 to 3 heteroatoms, sel
