Product Name: Tetramethylammonium Hydroxide
CAS Number: 75-59-2
Common Synonyms: TMAH, Tetramethylammonium hydrate
Product Use: Photoresist developer, etchant, laboratory reagent
Supplier: Listed chemical suppliers and distributors
Contact Information: Emergency phone numbers provided by supplier
Molecular Formula: (CH₃)₄NOH
Molecular Weight: 91.15 g/mol
Recommended Restrictions: Professional, industrial, and laboratory use only
Classification: Acute toxicity (Oral, Dermal, Inhalation); Skin corrosion/irritation; Serious eye damage
Signal Word: Danger
Hazard Statements: Fatal if swallowed, in contact with skin, or if inhaled. Causes severe skin burns and eye damage.
Precautionary Statements: Avoid contact with skin and eyes. Wash hands thoroughly after handling. Wear protective gear.
Health Hazards: Respiratory irritation, severe tissue damage, risk of death from systemic poisoning
Environmental Hazards: Highly toxic to aquatic life with long-lasting effects
Chemical Name: Tetramethylammonium Hydroxide
CAS Number: 75-59-2
Concentration: 20–25% in water for common solutions; solutions of other concentrations available
Other Components: Water (to balance), possible stabilizers or trace impurities
Inhalation: Remove victim to fresh air, keep at rest, seek immediate medical attention
Skin Contact: Remove contaminated clothing, rinse skin with plenty of water for at least 15 minutes, get medical help
Eye Contact: Rinse cautiously with water for at least 15 minutes, lift eyelids, seek immediate ophthalmological advice
Ingestion: Do not induce vomiting, rinse mouth, seek medical advice immediately
General Advice: Ensure rescuers wear appropriate protection, act swiftly as symptoms may appear rapidly
Suitable Extinguishing Media: Use dry chemical, CO₂, alcohol-resistant foam, or water spray
Special Hazards: May produce toxic fumes under fire conditions, including nitrogen oxides, methylamines
Protective Equipment: Firefighters should use self-contained breathing apparatus, chemical-resistant clothing
Firefighting Measures: Move containers from fire area if safe, cool unopened containers with water spray, avoid inhaling fumes
Personal Precautions: Ventilate area, evacuate unnecessary personnel, use appropriate PPE
Environmental Precautions: Prevent entry to sewers, soil, waterways
Methods for Containment: Absorb spill with non-combustible material like sand or vermiculite, place in labeled containers for disposal
Clean-Up Procedures: Neutralize with diluted acid if possible, avoid splashing or direct contact, ventilate area thoroughly
Handling: Work in fume hood, avoid breathing vapors, prevent contact with skin and eyes, no eating or drinking in work area
Safe Storage Conditions: Store in tightly closed containers, in cool, dry, well-ventilated area away from incompatible substances (acids, oxidizers, aluminum, copper)
Storage Incompatibilities: Strong acids, strong oxidizers, light metals
Recommended Materials for Containers: High-density polyethylene or glass with compatible sealing
Occupational Exposure Limits: No established national guidelines, minimize exposure as much as possible
Engineering Controls: Local exhaust ventilation, eye wash stations, safety showers in immediate area
Personal Protection: Chemical splash goggles, face shield, chemical-resistant gloves (nitrile or neoprene), full protective clothing, suitable respiratory protection for high concentrations
Hygiene Measures: Remove contaminated clothing, wash skin thoroughly after use, do not reuse contaminated clothing before cleaning
Appearance: Colorless to pale yellow liquid or solid, depends on concentration and temperature
Odor: Ammonia-like
pH: 13-14 (strongly alkaline in solution)
Melting/Freezing Point: Data varies with concentration (solution typically does not freeze at room temperature)
Boiling Point: Varies with concentration (about 100 ºC for aqueous solutions)
Solubility: Highly soluble in water and most polar solvents
Vapor Pressure: Low for solution at room temperature
Flash Point: Non-flammable in aqueous form
Density: About 1.01 – 1.04 g/cm³ (solution)
Chemical Stability: Stable under recommended storage conditions
Hazardous Reactions: Contact with acids produces heat, possible splattering; can react with oxidizers violently
Incompatible Materials: Acids, strong oxidizers, light metals (may form explosive mixtures with nitrites or react to cause corrosion and hydrogen evolution)
Hazardous Decomposition: Methylamines, nitrogen oxides, ammonia released on decomposition
Conditions to Avoid: Heat, ignition sources, incompatible materials, contact with air for extended periods
Routes of Exposure: Inhalation, skin absorption, ingestion, eye contact
Acute Toxicity: Extremely toxic, causes rapid onset of symptoms and high risk of fatality
Skin and Eye Contact: Corrosive to tissue, potential for permanent scarring or blindness
Inhalation: Can cause respiratory failure, pulmonary edema, or death
Chronic Effects: No sufficient chronic toxicity data available; repeated exposure worsens acute symptoms
Carcinogenicity, Mutagenicity, Reproductive Toxicity: Not classified as a carcinogen
Other Symptoms: Nausea, vomiting, headache, confusion, severe pain
Aquatic Toxicity: Very toxic to aquatic organisms, causes long-term adverse effects in aquatic environment
Mobility: Miscible with water; moves rapidly in aquatic systems
Persistence and Degradability: Not readily biodegradable
Bioaccumulation: Unlikely to bioaccumulate in aquatic organisms
Other Harmful Effects: Raises pH of water, potentially lethal to fish and invertebrates even at low concentrations
Disposal Methods: Do not discharge to sewer or environment. Send to licensed chemical disposal company.
Contaminated Packaging: Rinse containers thoroughly before recycling or disposal. Handle as hazardous waste.
Special Precautions: Consult local, regional, or national regulations for specific guidelines.
Recycle/Recovery: Strongly discouraged; TMAH should be neutralized and treated as hazardous waste.
UN Number: UN 3439
Proper Shipping Name: Tetramethylammonium Hydroxide, Solution
Hazard Class: 8 (Corrosive)
Packing Group: I (high danger)
Labels: Corrosive, Toxic (if concentration triggers acute toxicity entries)
Special Precautions for Transport: Protect from mechanical shock, only trained personnel may handle in transit, keep containers upright and sealed tightly
OSHA Status: Regulated as highly toxic and corrosive
TSCA: Listed in US Toxic Substances Control Act
SARA Title III: May be subject to reporting requirements
REACH Status (EU): Registered use restrictions; substance of concern
Other National Regulations: Subject to strict transport, storage, and disposal controls globally
Label Information: Hazard pictograms, signal words, and precautionary statements required by GHS
