Product Name: Caustic Soda
Chemical Names: Sodium Hydroxide
Synonyms: Lye, NaOH, Caustic Flake
CAS Number: 1310-73-2
Manufacturer Contact: Listed on shipment paperwork; 24-hour emergency phone lines often included.
Recommended Use: Cleaning agent, pH regulation, chemical manufacturing, water treatment.
Non-Recommended Use: Use outside advised industrial settings without proper training or protective equipment causes harm and is not supported by any responsible manufacturer.
Hazard Class: Strong Alkali; Corrosive to skin, eyes, respiratory tract.
GHS Label: Danger; includes pictogram with corrosive symbol.
Hazard Statements: Causes severe skin burns and eye damage; highly irritating to mucous membranes.
Routes of Exposure: Inhalation, skin contact, eye contact, ingestion.
Acute Symptoms: Burning pain, respiratory discomfort, visual disturbance.
Chronic Symptoms: Prolonged exposure results in dermatitis or permanent eye injury.
Precautionary Statements: Avoid breathing dust or mist; Use only outdoors or in well-ventilated area; Keep away from children.
Chemical Identity: Sodium Hydroxide
Concentration: Typically above 97% for industrial-grade solids; varies in solutions.
Impurities: Trace amounts of sodium carbonate, sodium chloride depending on manufacturer and grade.
Relevant Thresholds: Occupational standards for sodium hydroxide apply above 2 mg/m3 in air.
Inhalation: Remove from exposure immediately to fresh air. If breathing gets difficult, medical intervention comes next. Support breathing as required.
Skin Contact: Take off all contaminated clothing right away. Rinse skin thoroughly with plenty of water for 15 minutes; do not neutralize caustic with acids because heat increases tissue damage.
Eye Contact: Flush eyes gently but thoroughly for a full 20 minutes, use eyewash station if available. Removing contact lenses helps if easy to do; seek urgent medical attention.
Ingestion: Do not induce vomiting. Rinse mouth and drink small amounts of water if conscious and alert. Immediate medical attention is necessary; do not leave person unattended.
Flammability: Sodium hydroxide itself is not combustible, but reacts vigorously with certain metals, especially aluminum or zinc, producing hydrogen gas—creates a fire or explosion hazard.
Suitable Extinguishing Media: Use water spray, dry powder, or foam for surrounding materials burning. Avoid contact with water on concentrated dry caustic as it creates heat and hazardous splatter.
Hazardous Combustion Byproducts: Hydrogen gas, caustic fumes.
Personal Protective Equipment: Firefighters wear full turnout gear and self-contained breathing apparatus.
Personal Protection: Ensure all responders wear chemical-resistant gloves, goggles, boots, long sleeves. Respiratory protection recommended for airborne dust or mist.
Spill Response: Keep away from water sources that lead to public sewers. Contain using sand or inert absorbent; small spills swept up into suitable container.
Cleanup: Neutralize residue with dilute vinegar or acetic acid—controlled, slow addition reduces heat and vapor release. Decontaminate area with excess water only after initial cleanup.
Environmental Care: Prevent runoff into soil, groundwater or surface water; report significant spills to authorities.
Handling: Transfer carefully with designated, corrosion-resistant containers. Avoid physical contact; never eat, drink, or smoke near caustic soda use points. Keep containers tightly closed and labeled where necessary.
Storage: Keep in cool, dry, well-ventilated location. Use containers of high-density polyethylene or steel with protective lining. Store away from acids, metals, explosives, and flammable liquids. Store at ambient temperatures to keep solid from clumping and solutions from freezing or boiling over.
Special Considerations: Access limited to trained professionals. Emergency showers and eyewash stations remain nearby.
Occupational Exposure Limit: 2 mg/m3 Ceiling Value (OSHA/NIOSH).
Engineering Controls: Use strong local exhaust ventilation at points of dust, vapor, or solution splash. Implement systems for closed transfer whenever possible.
Personal Protection: Wear impervious gloves (nitrile, neoprene), chemical splash goggles, face shield, full suit or apron for skin protection. Appropriate respiratory protection (such as NIOSH-approved masks) needed in areas of high airborne dust or mist.
Hygiene Measures: Wash hands thoroughly after handling. Separate work clothes from street clothes; launder daily to avoid contamination outside the workplace.
Appearance: White, odorless solid (flakes, beads) or colorless, clear solution.
Molecular Formula: NaOH
Molecular Weight: 40.00 g/mol
Boiling Point: 1388°C (solid)
Melting Point: 318°C (solid)
Solubility: Highly soluble in water, releasing heat.
pH (1% Solution): About 14
Density: 2.13 g/cm3 (solid)
Odor: Odorless (but rapidly causes irritation on exposure)
Vapor Pressure: Negligible at room temperature; solutions release mist if handled at elevated temperatures.
Chemical Stability: Remains stable in air and water, reacts vigorously with acids, releases heat.
Incompatible Materials: Strong acids, ammonia, metals like aluminum, tin, and zinc (generate flammable hydrogen gas); halogenated organics.
Hazardous Decomposition: Hydrogen gas, excessive heat, possible formation of caustic mists during improper dilution.
Conditions to Avoid: Moisture in storage for solids, excessive heating of solutions, unprotected contact with incompatible materials.
Acute Toxicity: Causes severe tissue damage on direct contact. Oral LD50 (rat): 325 mg/kg (for anhydrous).
Inhalation: Severe irritation, possible damage to the respiratory tract.
Skin: Burns, ulceration, scarring.
Eyes: Permanent injury, blindness if not rapidly washed out.
Long-Term Effects: Scar tissue formation, narrowing of throat or esophagus if swallowed.
Carcinogenicity: Not classified as carcinogen by IARC, NTP, OSHA.
Other Toxicology Data: Prolonged exposure worsens symptoms and recovery time.
Aquatic Effects: Greatly raises water pH, proving toxic to fish and invertebrates at low concentrations. Disrupts ecosystems where released.
Soil Impact: Alters soil chemistry, increases salinity and pH, harming plant life.
Degradation: Not biodegradable; dissociates in water.
Bioaccumulation: Low potential, but high local impact due to pH shift.
Environmental Regulations: Strict discharge limits enforced in many regions.
Waste Handling: Neutralize with dilute acid under controlled conditions, confirm by pH testing before disposal. Never mix with incompatible waste.
Disposal Methods: Send to permitted hazardous waste facilities following all local, state, and federal requirements.
Container Rinsing and Recycling: Rinse thoroughly before recycling; never reuse containers for food or personal use.
Special Precautions: Do not allow residuals to enter public water systems or storm drains.
UN Number: UN1823 (solid); UN1824 (solution)
Proper Shipping Name: Sodium Hydroxide, Solid or Solution
Hazard Class: 8 (Corrosive Substances)
Packing Group: II
Labels: Corrosive placards must be visible during transport.
Special Transport Instructions: Ensure secure packaging; separate from acids and celebratory pyrotechnics. Emergency procedures must address leaks, spills, and exposure.
TSCA Status: Listed; legal for manufacture and distribution in the United States.
SARA Title III: Reportable under sections 302, 304, and 311/312 for large releases.
Workplace Regulation: OSHA covers Sodium Hydroxide under permissible exposure limits; annual safety training required.
Community Right-To-Know: Local fire and emergency response authorities require notification if stored in significant volume.
International Listings: Present in Canadian DSL, European EINECS, and most international chemical inventories.
Hazard Communication: Safety Data Sheets required at all points of use and sale; labeling follows GHS standards worldwide.
