Sodium Hydroxide 50% Solution ACS Grade

Product Identifier

Sodium Hydroxide 50% Solution ACS Grade

Grade

ACS Grade

Concentration

50%

CAS Number

1310-73-2

Manufacturer

Alliance Chemical
204 South Edmond Street, Taylor, TX 76574

Emergency Phone

Chemtel 1-800-255-3924 (24/7)

Synonyms

Caustic soda solution; lye; sodium hydrate

Recommended Use

Laboratory and analytical reagent (ACS grade); pH adjustment and neutralization; cleaning and degreasing.

Restrictions on Use

For industrial and professional use. Always add caustic slowly to water, never water to caustic.

Classification

• Corrosive to metals, Category 1
• Skin corrosion/irritation, Category 1
• Serious eye damage/eye irritation, Category 1

Signal Word

Danger

Hazard Statements

• H290May be corrosive to metals
• H314Causes severe skin burns and eye damage

Precautionary Statements

• P234Keep only in original packaging.
• P260Do not breathe dust, fume, gas, mist, vapors or spray.
• P264Wash hands and face thoroughly after handling.
• P280Wear protective gloves, protective clothing, and eye/face protection.
• P301+P330+P331IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
• P303+P361+P353IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
• P304+P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
• P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
• P310Immediately call a POISON CENTER or doctor.
• P321Specific treatment (see first-aid information on this label).
• P363Wash contaminated clothing before reuse.
• P390Absorb spillage to prevent material damage.
• P405Store locked up.
• P406Store in a corrosion resistant container with a resistant inner liner.
• P501Dispose of contents and container in accordance with local, regional, national, and international regulations.

Classification, hazard (H) and precautionary (P) statements and pictograms per OSHA HCS 2024 (29 CFR 1910.1200, Appendices A–C), aligned with GHS Rev. 7.

Concentrations are nominal; lot-specific values appear on the Certificate of Analysis. Components not contributing to classification are omitted.

Eyes

Rinse with plenty of water for at least 15 minutes. Remove contact lenses if present and easy to do. Continue rinsing. Seek medical attention immediately.

Skin

Immediately flush with plenty of water for at least 15 minutes while removing contaminated clothing. Wash with soap. Get medical attention immediately.

Inhalation

Move person to fresh air and keep comfortable for breathing. If breathing is difficult, give oxygen. If not breathing, give artificial respiration. Get medical attention immediately.

Ingestion

Do Not Induce Vomiting! Never give anything by mouth to an unconscious person. If conscious, wash out mouth with water. Get medical attention immediately.

Most Important Symptoms and Effects

• Causes burns to the skin, eyes and mucous membranes; eye contact may cause permanent damage including blindness; ingestion burns the mouth, throat and stomach.

Immediate Medical Attention and Special Treatment

• Immediate medical attention is required after eye or skin contact or ingestion; tissue damage may continue after exposure ends.

Suitable Extinguishing Media

Dry chemical, CO2, water spray. Use water spray to cool containers.

Unsuitable Extinguishing Media

Do not use a solid water stream as it may scatter and spread fire.

Specific Hazards Arising from the Chemical

Fire may release corrosive and toxic gases. Containers may rupture when heated.

Protective Equipment

Wear self-contained breathing apparatus and full protective clothing.

Hazardous Combustion Products

Sodium oxide and corrosive vapors on strong heating. Contact with metals releases flammable hydrogen gas.

Personal Precautions

Use PPE as described in Section 8. Ensure adequate ventilation. Evacuate personnel to safe areas.

Hazard-Specific Precautions

Do not touch spilled material without protective equipment. Neutralize residue only with a method suitable for the material, then collect.

Environmental Precautions

Prevent leakage or spillage from entering drains, sewers, or waterways.

Containment & Cleanup

Absorb with inert material. Collect in appropriate waste container. Dispose per applicable regulations.

Safe Handling

Use with adequate ventilation. Avoid contact with skin, eyes, and clothing. Wash thoroughly after handling. Keep container closed when not in use.

Safe Storage

Store in a cool, dry, well-ventilated area. Use corrosion-resistant containers. Keep away from incompatible materials (see Section 10). Keep containers tightly closed.

Specific Storage Precautions

Store above 15 °C (59 °F): 50% caustic crystallizes at about 12 °C (54 °F). Use steel, polyethylene or polypropylene containers, never aluminum, zinc, tin or galvanized metal. Keep away from acids.

Occupational Exposure Limits

Engineering Controls

Use adequate ventilation. Provide eyewash stations and quick-drench showers accessible to areas of use.

Eye/Face Protection

Wear chemical safety goggles or face shield.

Skin Protection

Wear chemical-resistant gloves and protective clothing.

Respiratory Protection

Where mist, spray or dust is generated (e.g., spraying, atomization, pressure washing), use a NIOSH-approved half-face air-purifying respirator with combination acid gas / P100 cartridges. Ensure local exhaust ventilation.

Exposure limits sourced from NIOSH Pocket Guide, OSHA 29 CFR 1910.1000 and ACGIH TLVs.

Appearance

Clear, colorless liquid

Odor

Odorless

Odor Threshold

No data available

pH

13–14

Melting Point / Freezing Point

10 to 15 °C (50 to 59 °F), freezing point (aqueous solution)

Boiling Point

142 to 145 °C (288 to 293 °F) (aqueous solution)

Flash Point

No data available

Evaporation Rate

No data available

Flammability (solid, gas)

No data available

Upper/Lower Flammability or Explosive Limits

No data available

Vapor Pressure

1.2 hPa (0.9 mmHg); 6.3 mmHg at 40 °C

Vapor Density

No data available

Relative Density

1.520 - 1.545

Solubility

Completely miscible with water (strongly exothermic)

Partition Coefficient (n-octanol/water)

No data available

Auto-ignition Temperature

No data available

Decomposition Temperature

No data available

Viscosity

No data available

Particle Characteristics

Not applicable

Form

Liquid

Density

1.53 (50% w/w aqueous solution, 20 °C)

Values shown reflect product-specific canonical data. Lot-specific ranges may vary; see the Certificate of Analysis for the shipped lot.

Reactivity

May be corrosive to metals.

Chemical Stability

Stable under recommended storage conditions.

Possibility of Hazardous Reactions

None under normal processing conditions.

Conditions to Avoid

Temperatures below about 15 °C (crystallization), contact with incompatible materials, and adding water to the concentrate (violent heat release).

Incompatible Materials

Acids (violent reaction); aluminum, zinc, tin, magnesium and their alloys, including galvanized metal (releases flammable hydrogen); organic halogen compounds; nitro compounds; flammable liquids; strong oxidizers.

Hazardous Decomposition Products

Sodium oxide and corrosive vapors on strong heating. Contact with metals releases flammable hydrogen gas.

See below for route-specific acute toxicity data.

Likely Routes of Exposure

Inhalation, skin contact, eye contact, ingestion.

Symptoms

• Causes burns to the skin, eyes and mucous membranes; eye contact may cause permanent damage including blindness; ingestion burns the mouth, throat and stomach.

Delayed and Chronic Effects

• No delayed or chronic effects identified beyond the classification in Section 2.

Carcinogen Classification

Ecotoxicity

Daphnia EC50: 40.38 mg/L (48 h, Ceriodaphnia dubia (<24 h neonate) — pH-driven; 95% CI 34.59–47.13 mg/L); Fish LC50: 125 mg/L (96 h, Gambusia affinis (mosquitofish) — pH-driven)

Persistence & Degradability

Not applicable (inorganic; dissociates to Na⁺ and OH⁻)

Bioaccumulative Potential

Not Available

Mobility in Soil

Highly water-soluble

Dispose of contents/container in accordance with applicable federal, state, and local regulations. Do not dispose of into drains or waterways.

If discarded, this material may be a corrosive hazardous waste (EPA RCRA D002, 40 CFR 261.22): aqueous with pH ≤ 2 or ≥ 12.5, or a liquid that corrodes steel at more than 6.35 mm per year. The waste generator must make the final hazardous-waste determination.

US DOT (49 CFR)

UN Number

UN1824

Proper Shipping Name

Sodium hydroxide solution

Hazard Class

8

Packing Group

II

Additional US DOT Requirements

A package containing 1,000 lb or more of sodium hydroxide (about 2,000 lb or 160 gal of 50% solution, for example a 275-gal tote) is a hazardous substance: UN1824, Sodium hydroxide solution, 8, II, RQ (Sodium hydroxide). Not a marine pollutant.

IMDG / IATA classifications may differ from US DOT. Verify current regulations before international shipment.

CERCLA Reportable Quantity (RQ)

Sodium hydroxide (CAS 1310-73-2) 1,000 lb (454 kg), about 2,000 lb of 50% solution.

SARA 311/312 hazard categories correspond to the GHS classification in Section 2. Data retrieved as of: California Proposition 65 2026-10-02; US EPA TSCA Active Inventory 2026-10-02; EPCRA SARA 313 (TRI) 2026-10-02.

Revision Date

2026-10-07

Format

16-section format per OSHA HCS 2024 (29 CFR 1910.1200, Appendix D), aligned with GHS Rev. 7.