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Tetramethylammoniumhydroxid
TMAH · TetramethyL · Developer · Tetramethylammonium hydroxide, 10% in water · TMNOH · N,N,N-TRIMETHYLMETHANAMINIUM HYDROXIDE · Tetramethylammonium hydroxide, 25% w/w in methanol · TETRAMETHYLAMMONIUM HYDROXIDE SOL., 6% IN PROPYLENEGLYCOL
Identifikatoren & physikalische Daten
| CAS No. | 75-59-2 |
|---|---|
| Summenformel | C4H12N.HO |
| Durchschnittliche Molmasse | 91,15 g/mol |
| Monoisotopische Masse | 91,09971404 g/mol |
| SMILES | C[N+](C)(C)C.[OH-] |
| InChIKey | WGTYBPLFGIVFAS-UHFFFAOYSA-M |
| PubChem CID | 60966 |
| ChEMBL | CHEMBL3187523 |
| EC No. | 200-882-9 |
| DTXSID | DTXSID3029108 |
| Lokaler Name | Tetramethylammoniumhydroxid |
Chemische & physikalische Eigenschaften
| Polarare Oberfläche (TPSA) | 1 |
|---|---|
| H-Brücken-Donoren | 1 |
| H-Brücken-Akzeptoren | 1 |
| Frei drehbare Bindungen | 0 |
| Schwere Atome | 6 |
| Formalladung | 0 |
| Komplexität | 19,1 |
| Stoffklassen | Other Classes -> BasesCorrosives |
| Geruch | Strong ammonia-like |
| Dichte | Specific gravity of solution approximately 1.00 at 24 °C/4 °C1 @25 °C0.866 g/mL at 25 °C |
| Color/Form | The free base is known only in solution or as a solid pentahydrate, forming colorless, deliquescent needlesLiquid |
| Corrosivity | Corrosive |
| Decomposition | When heated to decomposition it emits toxic fumes of /nitrogen oxides and ammonia/. |
| Schmelzpunkt | 63 °C |
| Physical Description | Tetramethylammonium hydroxide is a solid in the hydrated form or a colorless liquid with a strong ammonia-like odor. It is soluble in water. It is corrosive to metals and tissue.Dry PowderColorless liquid with an ammonia-like odor[CAMEO] |
| Stability/Shelf Life | Stable under recommended storage conditions. /Tetramethylammonium hydroxide pentahydrate/ |
| Other Experimental Properties | Decomposes to trimethylamine and methanol upon distillationReadily absorbs CO2 from the airWhen heated to decomposition it emits toxic fumes of NOx and NH3.Concn: 25 wt% in water. VP: 17.5 mm Hg at 20 °CIndex of refraction: 1/3806 at 20 °C/Ddensity: 1.106 g/mL at 25 °C /Tetramethylammonium hydroxide solution/ |
| Siedepunkt | 110 °C |
| Dampfdruck | 17.5 mm Hg ( 20 °C) |
| Brechungsindex | n20/D 1.384 |
| Flammpunkt | 80 °F |
| Lagerbedingungen | Store below +30°C. |
| Löslichkeit | Methanol (Sparingly), Water (Slightly)Soluble in water. |
| Aggregatzustand | Solution |
| Farbe | APHA: ≤10 |
| Geruch | strong ammonia-like odor |
| pH | >13 (H2O, 20°C) |
| Merck | 14,9224 |
| BRN | 3558708 |
| Henry-Konstante | 2.3×1010 mol/(m3Pa) at 25℃, HSDB (2015) |
| Stabilität | Stable. Flammable. Incompatible with strong oxidizing agents, strong acids. |
| InChI | 1S/C4H12N.H2O/c1-5(2,3)4/h1-4H31H2/q+1/p-1 |
| InChIKey | WGTYBPLFGIVFAS-UHFFFAOYSA-M |
| SMILES | [OH-].C[N+](C)(C)C |
| CAS Datenbank | 75-59-2(CAS DataBase Reference) |
| EPA chemische Informationen | Tetramethylammonium hydroxide (75-59-2) |
Sicherheit & Vorschriften
| GHS-Einstufung | DangerH300+H310 (36%): Fatal if swallowed or in contact with skin [Danger Acute toxicity, oralacute toxicity, dermal]P260, P262, P264, P264+P265, P270, P273, P280, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P308+P316, P316, P317, P319, P321, P330, P361+P364, P363, P391, P405, and P501 (click each P-code to see the statement)Aggregated GHS information provided per 559 reports by companies from 44 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.H300: Fatal if swallowed [Danger Acute toxicity, oral] |
|---|---|
| Regulatorische Informationen | Chemical: Methanaminium, N,N,N-trimethyl-, hydroxideMethanaminium, N,N,N-trimethyl-, hydroxide (1:1) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Methanaminium, N,N,N-trimethyl-, hydroxide (1:1) 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: Active Update: 17-05-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/14295Tetramethylammonium hydroxide: Does not have an individual approval but may be used under an appropriate group standardThe 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.) |
| Weitere Sicherheitsinformationen | IMAP assessments - Tetramethylammonium hydroxide and its pentahydrate: Human health tier II assessment |
| DOT-Kennzeichnung | Corrosive |
| Brandgefahren | Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:· Combustible material: may burn but does not ignite readily. |
| Brandpotenzial | Not flammable or combustible. /Tetramethylammonium hydroxide pentahydrate/ |
| Gesundheitsgefahren | Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:· TOXIC and/or CORROSIVEinhalation, ingestion or skin contact with material may cause severe injury or death. |
| Gefahrenübersicht | May cause burns and eye damageAt high concentrations, may cause cough, wheezing, and fluid in the lungs[CSH, p. 405] A very strong base that forms corrosive alkaline solutions[CHEMINFO-MSDS] A corrosive substance that can cause injury to the skin, eyes, and respiratory tract[CAMEO] |
| DOT-Nummer und Handbuch | 1835 1533423 153 |
| Reaktive Gruppe | Bases, Strong |
| Reactivity Profile | TETRAMETHYLAMMONIUM HYDROXIDE acts like a base. Bases are chemically similar to sodium hydroxide (NaOH) or sodium oxide (Na2O). They neutralize acids exothermically to form salts plus water. When soluble in water they give solutions having a pH greater than 7.0. Mixing these materials with water can generate troublesome amounts of heat as the base is dissolved or diluted. Bases react with certain metals (such as aluminum and zinc) to form oxides or hydroxides of the metal and generate gaseous hydrogen. Bases may initiate polymerization reactions in polymerizable organic compounds, especially epoxides). They may generate flammable and/or toxic gases with ammonium salts, nitrides, halogenated organics, various metals, peroxides, and hydroperoxides. Materials of this group often serve as catalysts. |
| History and Incidents | ... The purpose of this study was to examine the cause of an accidental death from acute poisoning resulting from exposure to a cleaner containing tetramethylammonium hydroxide (TMAH) and to consider measures to prevent future cases. ... The authors examined the details and the reason for the accidental death from acute poisoning based on the autopsy report. ... The victim was a 39-year-old male researcher with 7 years of work experience employed by a surfactant production company. The accident occurred when he was conducting a field test of a newly developed cleaner, containing 8.75% TMAH solution. The researcher spilled the cleaner on his work clothes in the area of both the hands/arms and legs. He was unconscious when discovered. An autopsy found no damage or injury that could have resulted in death other than burns to 12% of his body, and the cause of death was found to be acute poisoning by TMAH. ... TMAH is widely used in the electronics industry as a developer or cleaner. It is a dangerous material, causing neurotoxicity leading to respiratory failure by ganglion block that occurs through skin absorption, and no antidote has been developed yet. For this reason, it is best to completely prevent exposure by wearing proper personal protective equipment. Despite this fatal toxicity of TMAH, it is not classified in Korea as a "chemical requiring legal control". For this reason, it is urgent to raise awareness of the toxic properties of TMAH to prevent additional cases of TMAH poisoning.Tetramethylammonium hydroxide (TMAH) is widely used as a developer or etchant in semiconductor and photoelectric industries. In addition to alkalinity-related chemical burn, dermal exposure to TMAH may also result in respiratory failure and/or sudden death. The latter toxic effect has been of great concern in Taiwan after the occurrence of three fatalities in recent years. To better understand the toxicity following dermal exposure to TMAH, we analyzed all cases with TMAH exposure reported to the Taiwan Poison Control Center (PCC-Taiwan). ... In total, there were 13 cases of such exposure, including three patients who died after being exposed to 25% TMAH. A worker also developed severe effects manifesting muscle weakness, dyspnea, hyperglycemia, and chemical burn (28% of total body surface area) shortly after an accidental exposure to 2.38% TMAH. He received endotracheal intubation with assisted ventilation for 2 days and survived. ... Skin corrosive injury related to the alkalinity of TMAH and the ganglionic toxicity of tetramethylammonium ion might contribute to the clinical manifestations that occurred after dermal TMAH exposure. Thorough skin decontamination followed by prompt respiratory support should be the mainstay in the management of dermal TMAH exposure. Preventive strategies are warranted as well to decrease future occupational TMAH exposures. |
| DOT Emergency Guidelines | /GUIDE 153: SUBSTANCES - TOXIC AND/OR CORROSIVE (COMBUSTIBLE)/ Health: TOXICinhalation, ingestion, or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. /Tetramethylammonium hydroxideTetramethylammonium hydroxide, solidTetramethylammonium hydroxide, solution//GUIDE 153: SUBSTANCES - TOXIC AND/OR CORROSIVE (COMBUSTIBLE)/ Fire or Explosion: Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors, and sewers explosion hazards. Those substances designated with a "P" may polymerize explosively when heated or involved in a fire. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form. /Tetramethylammonium hydroxide/GUIDE 153: SUBSTANCES - TOXIC AND/OR CORROSIVE (COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas. /Tetramethylammonium hydroxide/GUIDE 153: SUBSTANCES - TOXIC AND/OR CORROSIVE (COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLYit is not effective in spill situations where direct contact with the substance is possible. /Tetramethylammonium hydroxideFor more DOT Emergency Guidelines (Complete) data for Tetramethylammonium hydroxide (8 total), please visit the HSDB record page. |
| Brandbekämpfung | Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]: |
| Freisetungsmaßnahmen | · 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. |
| Erste Hilfe | Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:General First Aid: |
| Expositionsschutz und Persönliche Schutzausrüstung | · Wear positive pressure self-contained breathing apparatus (SCBA). |
| Brandbekämpfungsverfahren | If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flodding quantities as fog. Cool all affected containers with flooding quantities of water. Applyy water from as far a distance as possible. Solid streams of water may be ineffective. Use "alcohol" foam, dry chemical or carbon dioxide.Personnel protection: ... Wear positive pressure self-contained breathing apparatus when fighting fires involving this material.Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide. Special protective equipment for firefightersWear self contained breathing apparatus for fire fighting if necessary. /Tetramethylammonium hydroxide pentahydrate/ |
| Lagerbedingungen | Keep container tightly closed in a dry and well-ventilated place. Store under inert gas. Air sensitive. hygroscopic. /Tetramethylammonium hydroxide pentahydrate/ |
| Reinigungsverfahren | Personal precautions: Wear respiratory protection. Avoid dust formation. Avoid breathing vapours, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal. /Tetramethylammonium hydroxide pentahydrate/ |
| Freisetung ohne Brand | Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]: |
| Entsorgungsverfahren | SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. 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 qualitypotential migration in soil or watereffects on animal and plant lifeand conformance with environmental and public health regulations.Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. Contaminated packaging: Dispose of as unused product. /Tetramethylammonium hydroxide pentahydrate/ |
| Preventive Measures | If material not on fire and not involved in fire: Keep material out of water sources and sewers. Build dikes to contain flow as necessary.Personal protection: Avoid breathing vapors. Keep upwind. Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. ... If contact with the material is anticipated, wear appropriate chemical protective clothing.Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Provide appropriate exhaust ventilation at places where dust is formed. /Tetramethylammonium hydroxide pentahydrate/Avoid contact with skin, eyes and clothing. Wash hands before breaks and immediately after handling the product. /Tetramethylammonium hydroxide pentahydrate/For more Preventive Measures (Complete) data for Tetramethylammonium hydroxide (7 total), please visit the HSDB record page. |
| Isolation and Evacuation | Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:Immediate precautionary measure |
| Protective Action Criteria (PAC) | 0.0086 [mg/m3]0.095 [mg/m3]0.57 [mg/m3] |
| Umweltverhalten | TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 8(SRC), determined from a structure estimation method(2), indicates that tetramethylammonium hydroxide is expected to have very high mobility in soil(SRC). Volatilization of tetramethylammonium hydroxide from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.6X10-16 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Tetramethylammonium hydroxide is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.2X10-6 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). A 96% of theoretical BOD using activated sludge in the Japanese MITI test(4) suggests that biodegradation is an important environmental fate process in soil(SRC).AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 8(SRC), determined from a structure estimation method(2), indicates that tetramethylammonium hydroxide is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 4.6X10-16 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of -2.47(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). A 96% of theoretical BOD using activated sludge in the Japanese MITI test(6) suggests that biodegradation is an important environmental fate process in water(SRC).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), tetramethylammonium hydroxide, which has an estimated vapor pressure of 1.2X10-6 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase tetramethylammonium hydroxide is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC)the half-life for this reaction in air is estimated to be 2 days(SRC), calculated from its rate constant of 5.1X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase tetramethylammonium hydroxide may be removed from the air by wet and dry deposition(SRC). Tetramethylammonium hydroxide does not contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). |
| Unerwünschte Wirkungen | Dermatotoxin - Skin burns. |
| Soil Adsorption/Mobility | Using a structure estimation method based on molecular connectivity indices(1), the Koc of tetramethylammonium hydroxide can be estimated to be 8(SRC). According to a classification scheme(2), this estimated Koc value suggests that tetramethylammonium hydroxide is expected to have very high mobility in soil. |
| Human Toxicity Excerpts | /SIGNS AND SYMPTOMS/ Extremely destructive to tissue of the mucous membranes and upper respiratory tract, eyes, and skin. Inhalation may be fatal as a result of spasm, inflammation and edema of the larynx and bronchi, chemical pneumonitis, and pulmonary edema./CASE REPORTS/ Tetramethylammonium hydroxide (TMAH) is widely used as a developer or etchant in semiconductor and photoelectric industries. In addition to alkalinity-related chemical burn, dermal exposure to TMAH may also result in respiratory failure and/or sudden death. The latter toxic effect has been of great concern in Taiwan after the occurrence of three fatalities in recent years. To better understand the toxicity following dermal exposure to TMAH, we analyzed all cases with TMAH exposure reported to the Taiwan Poison Control Center (PCC-Taiwan). In total, there were 13 cases of such exposure, including three patients who died after being exposed to 25% TMAH. A worker also developed severe effects manifesting muscle weakness, dyspnea, hyperglycemia, and chemical burn (28% of total body surface area) shortly after an accidental exposure to 2.38% TMAH. He received endotracheal intubation with assisted ventilation for 2 days and survived. Skin corrosive injury related to the alkalinity of TMAH and the ganglionic toxicity of tetramethylammonium ion might contribute to the clinical manifestations that occurred after dermal TMAH exposure. Thorough skin decontamination followed by prompt respiratory support should be the mainstay in the management of dermal TMAH exposure. Preventive strategies are warranted as well to decrease future occupational TMAH exposures./CASE REPORTS/ The purpose of this study was to examine the cause of an accidental death from acute poisoning resulting from exposure to a cleaner containing tetramethylammonium hydroxide (TMAH) and to consider measures to prevent future cases. ... The victim was a 39-year-old male researcher with 7 years of work experience employed by a surfactant production company. The accident occurred when he was conducting a field test of a newly developed cleaner, containing 8.75% TMAH solution. The researcher spilled the cleaner on his work clothes in the area of both the hands/arms and legs. He was unconscious when discovered. An autopsy found no damage or injury that could have resulted in death other than burns to 12% of his body, and the cause of death was found to be acute poisoning by TMAH. TMAH is widely used in the electronics industry as a developer or cleaner. It is a dangerous material, causing neurotoxicity leading to respiratory failure by ganglion block that occurs through skin absorption, and no antidote has been developed yet. For this reason, it is best to completely prevent exposure by wearing proper personal protective equipment. Despite this fatal toxicity of TMAH, it is not classified in Korea as a "chemical requiring legal control". For this reason, it is urgent to raise awareness of the toxic properties of TMAH to prevent additional cases of TMAH poisoning./CASE REPORTS/ A 22 year old male engineer was accidentally drenched with concentrated tetramethylammonium hydroxide solution (TMAH) (25%, pH13.5) while conducting routine examination of the pipe system in a plant manufacturing thin film transistor liquid crystal displays (TFT0LCDs). He was wearing a clean room suit with plastic goggles, but not a mask. As TMAH sprayed over his head, he closed the valve and took a shower at the nearby emergency shower facility immediately for decontamination. When he was found by a co-worker about 15 minutes later, he suffered from general weakness and moderate salivation but was still conscious enough to describe the accident. the paramedical team arrived about 30 minutes after the accident and found the patient losing his consciousness with a Glasgow coma scale of 6 (E1V2M3). His pulse was weak and noted as 8-10 times per minute, and miosis was also noted. he lost vital signs about half an hour later on the way to the hospital. He was diagnosed as dead on arrival at the hospital, as neither pulse nor breath was foundno electroactivity was shown by the electrocardiogram, and miosis without reaction to light was noted. Multiple glossy and erythematous erosive wounds were noted over his perineum, all four limbs, and face except for the nares and mouth. After cardiopulmonary resuscitation with 2 mg epinephrine bolus injection and 500 mL normal saline challenge intravenously, his heart beats and blood pressure were restored, but he still needed invasive mechanical ventilation. Laboratory tests on the day of the accident revealed leukocytosis, hyperglycemia, and metabolic acidosis, but levels of aspartate aminotransferase (AS), alanine aminotransferase (ALT), blood urea nitrogen (BUN), creatinine, and electrolytes were all within normal limits. The results of chest X-ray examinations on admission and during follow-up excluded the diagnoses of inflammation airway and aspiration pneumonia. According to his family, he did not have any systemic diseases before this accident. Because he had second-degree chemical burns on 24% of the total body surface area (TBSA) and third-degree burns on 5% of the TBSA, he was admitted to the burn center for further management. He never regained consciousness and suffered from hypothermia, seizure, and electrolyte imbalance. He passed away eight days later. |
| Artificial Pollution Sources | Tetramethylammonium hydroxide's production and use as an etchant in circuit board production(1) and as a buffering agent, titrant, chemical reagent, and in digestion of biological samples(2) may result in its release to the environment through various waste streams(SRC). |
| Environmental Biodegradation | AEROBIC: Tetramethylammonium hydroxide, present at 100 mg/L, reached 96% of its theoretical BOD in 2 weeks using an activated sludge inoculum at 30 mg/L in the Japanese MITI test(1). |
| Environmental Bioconcentration | An estimated BCF of 3 was calculated in fish for tetramethylammonium hydroxide(SRC), using an estimated log Kow of -2.47(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC). |
| Volatilization from Water/Soil | The Henry's Law constant for tetramethylammonium hydroxide is estimated as 4.36X10-16 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that tetramethylammonium hydroxide is expected to be essentially nonvolatile from water surfaces(2). Tetramethylammonium hydroxide is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.2X10-6 mm Hg(SRC), determined from a fragment constant method(3). |
| Non-Human Toxicity Excerpts | /LABORATORY ANIMALS: Acute Exposure/ /The purpose of this study was/ to establish a rat model to investigate the effects of dermal exposure to TMAH. ... The 4-hour lethal dose (LD50) of tetramethylammonium hydroxide (TMAH) was determined by applying solutions mimicking the two most common industrially used concentrations (2.38% and 25%) of TMAH to the skin of Sprague-Dawley rats. Exposure of the rat's skin to 2.38% or 25% TMAH generated LD50 values of 85.9 mg/kg and 28.7 mg/kg, respectively. Application of either concentration of TMAH to the skin produced a rapid, significant increase in the rate of respiration. The serum concentrations of tetramethylammonium (TMA) also changed significantly with time of exposure to both concentrations of TMAH. The level of blood urea nitrogen decreased significantly in rats exposed to the 2.38% TMAH, and rats exposed to the 25% solution had a significant decrease in the serum concentration of sodium. Injection of atropine after 5 minutes of exposure did not significantly overcome any of the toxic effects observed with either solution of TMAH. The preliminary results in the rat model indicated that the lethality of TMAH cannot be fully explained by the severity of the patients' chemical burns, and the physiologic effects on respiratory and kidney functions were probably involved./OTHER TOXICITY INFORMATION/ To evaluate the role of the chemical burns caused by hydroxide ion in the fatal effects of tetramethylammonium ion (TMA) in dermal exposure to tetramethylammonium hydroxide (TMAH), /the researchers/ conducted a rat study consisting of two-step treatments with dermal exposure to NaOH and tetramethylammonium chloride (TMACl). In the first step, NaOH or saline was administered in the gauze on the shaved skin for 5 min, and in the second step, TMAH, TMACl, or saline was administered in the same way. The mean blood pressure (MBP), heart rate (HR), and survival in rats were compared among seven groups. Dermal exposure to saline and then 2.75 M TMACl introduced limited and temporary non-fatal effects. Exposure to 2.75 M NaOH and then saline had almost no effects and caused no deaths. Treatments with more concentrated NaOH or TMACl resulted in suppressions of MBP and HR, and deaths were observed after the dosing of TMACl. The toxicity of dermal exposure to TMA alone is limited, but fatal effects can be introduced by pre-treatment with hydroxide ion. Therefore, the chemical burn caused by hydroxide ion plays an essential role in the toxicity, implicating that effective neutralizing may help decreasing the fatality rate. |
| Environmental Abiotic Degradation | The rate constant for the vapor-phase reaction of tetramethylammonium hydroxide with photochemically-produced hydroxyl radicals has been estimated as 5.1X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Tetramethylammonium hydroxide is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). Tetramethylammonium hydroxide does not contain chromophores that absorb at wavelengths >290 nm(2) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). |
| Probable Routes of Human Exposure | According to the 2006 TSCA Inventory Update Reporting data, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use of tetramethylammonium hydroxide is 1000 or greaterthe data may be greatly underestimated(1).NIOSH (NOES Survey 1981-1983) has statistically estimated that 6,413 workers (1,446 of these were female) were potentially exposed to tetramethylammonium hydroxide in the US(1). Occupational exposure to tetramethylammonium hydroxide may occur through inhalation and dermal contact with this compound at workplaces where tetramethylammonium hydroxide is produced or used. General population exposure should be low or non-existent since tetramethylammonium hydroxide is not present in consumer end-use products(SRC). |
| Environmental Fate/Exposure Summary | Tetramethylammonium hydroxide's production and use as an etchant in circuit board production and as a buffering agent, titrant, chemical reagent, and in digestion of biological samples may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 1.2X10-6 mm Hg at 25 °C indicates tetramethylammonium hydroxide will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase tetramethylammonium hydroxide will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicalsthe half-life for this reaction in air is estimated to be 2 days. Particulate-phase tetramethylammonium hydroxide will be removed from the atmosphere by wet and dry deposition. Tetramethylammonium hydroxide does not contain chromophores that absorb at wavelengths >290 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight. If released to soil, tetramethylammonium hydroxide is expected to have very high mobility based upon an estimated Koc of 8. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 4.6X10-16 atm-cu m/mole. Tetramethylammonium hydroxide is not expected to volatilize from dry soil surfaces based upon its vapor pressure. Utilizing the Japanese MITI test, 96% of the Theoretical BOD was reached in 2 weeks indicating that biodegradation is an important environmental fate process in soil and water. If released into water, tetramethylammonium hydroxide is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions (pH 5 to 9). Occupational exposure to tetramethylammonium hydroxide may occur through inhalation and dermal contact with this compound at workplaces where tetramethylammonium hydroxide is produced or used. General population exposure should be low or non-existent since tetramethylammonium hydroxide is not present in consumer end-use products. (SRC) |
| F | 4.4-10-34 |
| Wassergefährdungsklasse (WGK) | 1 |
| TSCA-Inventar-Status | TSCA listed |
| UN-Transportnummer | UN 3423 6.1/PG I (TETRAMETHYLAMMONIUM HYDROXIDE, SOLID) |
| Zollcode | 29239000 |
| RTECS-Nr. | PA0875000 |
| R-Sätze (R) | 24/25-34-20/21/22-39/23/24/25-23/24/25-10-21/22-25-21-11-67-36-52-48/24-27/28-23-35-36/38 |
| Gefahrensymbole | C,T,F,T+,Xn |
| Sicherheitshinweise (S) | 45-36/37/39-26-16-36/37-28 |
| Gefahrenklasse | 3Acute Tox. 2 DermalAcute Tox. 2 OralAcute Tox. 3 InhalationAquatic Chronic 3Eye Dam. 1Flam. Liq. 3Skin Corr. 1BSTOT RE 1 DermalSTOT SE 1 |
| Verpackungsgruppe | II |
| Lagerklasse | 3 - Flammable liquids |
| Gefahrstoffdaten | 75-59-2(Hazardous Substances Data) |
Anwendungen & Verwendung
Beschreibung
Tetramethylammonium hydroxide is a solid in the hydrated form or a colorless liquid with a strong ammonia-like odor. It is soluble in water, and corrosive to metals and tissue.
Verwenden
Tetramethylammonium hydroxide is used to produce tetramethyl-ammonium azide. It is used as an anisotropic etchant of silicon, basic solvent in the development of acidic photoresist in photolithography process, as surfactant in the synthesis of ferrofluid and as a polarographic reagent. It finds application in the production of organic silicon, where it is used for computer silicon wafer surface brightener and cleaning agent. It is also involved in the purification of some metallic elements.Tetramethylammonium hydroxide solution (25 wt.% solution in water) may be used as a base for pH adjustment to obtain hexagonal mesoporous aluminophosphate (TAP).