NIOSH Pocket Guide to Chemical Hazards: Calcium Carbide (CaC₂)

Chemical Identification

Synonyms: Calcium acetylide

CAS Number: 75-20-7

Molecular Formula: CaC₂

Molecular Weight: 64.10 g/mol

Appearance: Grayish-black, lump solid with an odor of garlic.

Exposure Limits

OSHA PEL: No specific OSHA PEL

NIOSH REL: No specific NIOSH REL

ACGIH TLV: No specific ACGIH TLV

Physical and Chemical Properties

Boiling Point: Not applicable

Melting Point: 2,300°C (decomposes)

Solubility: Reacts with water to produce acetylene gas and calcium hydroxide.

Vapor Pressure: Not applicable

Specific Gravity: 2.22

Flammability: Reacts with water to form highly flammable acetylene gas.

Health Hazards

Routes of Exposure: Inhalation, ingestion, skin and eye contact.

Acute Effects: Exposure can cause irritation to the eyes, skin, and respiratory system. Inhalation of dust may lead to respiratory distress.

Chronic Effects: Prolonged or repeated exposure can cause chronic respiratory conditions.

Target Organs: Eyes, skin, respiratory system.

First Aid Measures

Inhalation: Remove to fresh air immediately. If breathing is difficult, administer oxygen. Seek medical attention if symptoms persist.

Skin Contact: Immediately wash with soap and water. Remove contaminated clothing. Seek medical attention if irritation persists.

Eye Contact: Rinse immediately with plenty of water for at least 15 minutes. Seek medical attention.

Ingestion: Do not induce vomiting. Rinse mouth thoroughly. Seek medical attention immediately.

Personal Protective Equipment (PPE)

Respiratory Protection: Use appropriate respiratory protection if exposure levels are exceeded.

Skin Protection: Wear protective gloves and clothing to prevent skin contact.

Eye Protection: Use safety glasses or goggles to protect eyes from dust and splashes.

Hygiene Measures: Wash hands thoroughly after handling. Do not eat, drink, or smoke while handling the material.

Handling and Storage

Handling: Handle in well-ventilated areas. Avoid creating dust and avoid contact with water.

Storage: Store in a cool, dry, well-ventilated area away from moisture and incompatible materials (e.g., acids).

Emergency Procedures

Spill/Leak Procedures: Avoid generating dust. Use non-sparking tools to collect material. Keep away from water sources.

Firefighting Measures: Use dry chemical, sand, or carbon dioxide. Do not use water. Evacuate area and fight fire from a safe distance.

Regulatory Information

DOT Classification: UN 1402, Calcium Carbide, Hazard Class 4.3 (Dangerous when wet)

EPA Regulations: Subject to reporting requirements under SARA Title III.

Additional Notes

Calcium carbide reacts violently with water, producing flammable acetylene gas and calcium hydroxide. Use caution when handling and ensure proper storage conditions to prevent accidental contact with water.

Disclaimer: This information is intended to serve as a guide for safe handling and exposure to calcium carbide. Users must ensure compliance with all applicable local, state, and federal regulations.