Sulfuric Acid

Classification

Skin corrosion, Category 1A

Hazard statements

• H314 Causes severe skin burns and eye damage.

Key precautionary statements

• P260 Do not breathe mist or vapors.
• P264 Wash hands thoroughly after handling.
• P280 Wear protective gloves, protective clothing, eye protection and face protection.
• P301+P330+P331 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
• P303+P361+P353 IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
• P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
• P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
• P310 Immediately call a POISON CENTER or doctor.

OSHA and NIOSH both set 1 mg/m³ as an 8-hour (NIOSH: 10-hour) TWA. ACGIH sets a much lower TLV of 0.2 mg/m³, measured as the thoracic particle fraction, because the main inhalation hazard is acid mist. No skin notation is assigned, but contact with concentrated acid causes severe burns. NIOSH advises an eyewash and quick drench shower where solutions stronger than 1% are used. State OSHA plans may set different limits.

• Appearance: Colorless to dark-brown, oily liquid. Often used as a water solution.
• Odor: Odorless
• Molecular weight: 98.1
• Boiling point: 554°F (290°C)
• Freezing point: 51°F (11°C); the pure compound is a solid below this temperature
• Flash point: Not applicable (noncombustible liquid)
• Explosive limits: Not applicable
• Vapor pressure: 0.001 mmHg
• Specific gravity: 1.84 (96–98% acid)
• Water solubility: Miscible; mixing with water releases a lot of heat

Inhalation

Mist irritates the nose and throat and can cause bronchitis. High exposure can cause fluid buildup in the lungs (pulmonary edema), a medical emergency that may be delayed.

Skin

Concentrated acid causes severe burns. Weaker solutions and repeated contact can cause irritation and dermatitis.

Eyes

Causes severe burns and conjunctivitis, and can cause permanent eye damage or blindness.

Ingestion

Causes severe burns of the mouth, throat and stomach. Get medical attention immediately.

Target organs

Eyes, skin, respiratory system, teeth

Long-term effects

Repeated exposure to acid mist can erode tooth enamel and cause mouth inflammation, emphysema and chronic lung problems. Occupational exposure to strong inorganic acid mists containing sulfuric acid is linked to cancer of the larynx, so exposure should be kept as low as possible.

Gloves

The New Jersey Department of Health lists butyl, Viton, Silver Shield/4H and Barrier as glove materials with more than 8 hours of breakthrough time.

Eyes and face

Chemical splash goggles and a face shield when pouring or handling concentrated acid.

Respiratory

Not normally needed with good ventilation. Where mist exceeds limits, NIOSH lists respirators with acid gas cartridges plus N100, R100 or P100 filters, or a powered air-purifying respirator with acid gas cartridges and HEPA filter, up to 15 mg/m³. Use a pressure-demand SCBA for emergencies or unknown concentrations.

Clothing

Acid-resistant apron, sleeves and boots; acid-resistant suits such as Tychem for large transfers or spills. Remove clothing promptly if wet or contaminated. Keep an eyewash and quick drench shower nearby.

Store in tightly closed, acid-resistant containers in a cool, dry, well-ventilated corrosives area. Keep away from water, moist air, organic materials and metals.

When diluting, always add acid slowly to water while stirring, never water to acid, because the reaction can boil and spatter. Use a fume hood or local exhaust where mist may form, and wash hands after handling.

Keep away from

• Water (violent reaction with heat release)
• Organic materials
• Chlorates
• Carbides
• Fulminates
• Powdered metals (and most metals, which release flammable hydrogen gas)

• Evacuate the area, keep people upwind and control entry.
• Wear acid-resistant gloves, clothing, goggles and face shield; use respiratory protection for mist.
• Do not use water on the spilled acid.
• Contain and neutralize with crushed limestone, soda ash or lime, or soak up with inert absorbent, and place residue in sealed containers.
• Keep out of drains, sewers and waterways, and ventilate the area.
• For larger incidents, refer to ERG Guide 137.

Suitable extinguishing media

• Use the agent best suited to the surrounding fire (sulfuric acid does not burn)
• Carbon dioxide, dry chemical or dry sand
• Do not put water directly on the acid

Special hazards

Noncombustible, but it can ignite finely divided combustible materials such as wood, paper and oil. Reacts with most metals to release flammable hydrogen gas. Fires produce toxic sulfur oxides, and containers may burst in heat. Firefighters should wear SCBA and full protective gear.

• OSHA Hazard Communication (29 CFR 1910.1200): Hazardous chemical; labels, safety data sheets and worker training required.
• OSHA Air Contaminants (29 CFR 1910.1000 Table Z-1): PEL 1 mg/m³ TWA.
• CERCLA hazardous substance (40 CFR 302.4): Reportable quantity 1,000 lb (454 kg).
• EPCRA Section 302 extremely hazardous substance (40 CFR 355 Appendix A): Threshold planning quantity 1,000 lb; reportable quantity 1,000 lb.
• EPCRA Section 313 / TRI (40 CFR 372.65): Listed for acid aerosols only (mists, vapors, gas, fog and other airborne forms).
• Clean Air Act 112(r) RMP (40 CFR 68.130): Sulfuric acid itself is not listed. Oleum (fuming sulfuric acid) is listed with a 10,000 lb threshold.
• DOT Hazardous Materials (49 CFR 172.101): UN1830 Sulfuric acid, Class 8, PG II.

• NIOSH Pocket Guide: Sulfuric acid
• PubChem: Sulfuric acid GHS classification
• Fisher Scientific SDS: Sulfuric acid
• NJ Department of Health Hazardous Substance Fact Sheet: Sulfuric acid
• eCFR: 40 CFR Part 355 Appendix A (EPCRA extremely hazardous substances)