What is Calcium Cyanamide?

Calcium cyanamide is a calcium compound with the molecular formula CaCN₂. It forms when calcium carbide reacts with nitrogen. It typically appears as glistening hexagonal crystals. Pure calcium cyanamide is non-volatile and non-combustible, but commercial grades may contain small amounts of calcium carbide. When calcium carbide decomposes in water, it produces highly flammable acetylene gas. Commercial grades often present as greyish-black powder or lumps.

Although calcium cyanamide is essentially insoluble in water, it undergoes partial hydrolysis to form calcium hydrogen cyanamide.

What is Calcium Cyanamide used for?

• Chemical Manufacturing: Used to produce calcium cyanide, melamine, and dicyandiamide
• Metal Hardening: Assists in hardening iron and steel
• Fertilizer: Serves as a nitrogen source for agricultural fertilizers
• Veterinary Medicine: Effective in eliminating parasitic worms
• Pesticidal Use: Previously registered as a pesticide but deregistered in California as of December 3, 1986

Sources & Routes of Exposure

Sources of Exposure

• Occupational exposure during manufacturing or application

Routes of Exposure

• Inhalation: Breathing dust or fumes
• Dermal Contact: Skin exposure during handling
• Ingestion: Accidental swallowing

Health Effect

Acute Effects

• Irritation: Affects eyes, skin, and respiratory tract
• Inhalation Exposure: May lead to gastritis, rhinitis, pharyngitis, laryngitis, and tracheobronchitis
• Oral Exposure: Can cause vasomotor reactions (facial flushing, headache, dizziness), nausea, vomiting, tachycardia, and hypotension
• Peripheral Neuropathy: Reported in rare cases following acute exposure
• Animal Studies: Demonstrate moderate to high acute toxicity from oral and dermal exposure

Chronic Effects

• Occupational Exposure: Chronic rhinitis and nasal septum perforation
• Dermal Exposure: Slow-healing ulcers
• Animal Data: Limited information; no Reference Concentration (RfC) or Dose (RfD) established by the EPA

Reproductive/Developmental Effects

• No available information in humans or animals

Cancer Risk

• No evidence of carcinogenic effects in humans
• National Toxicology Program studies in rats and mice found no carcinogenicity
• EPA has not classified calcium cyanamide regarding carcinogenicity

Calcium Cyanamide Safety

First Aid Measures

• Eye Contact: Flush with water for at least 15 minutes; seek immediate medical attention
• Skin Contact: Wash with water and cover with an emollient; seek medical attention
• Serious Skin Contact: Clean with disinfectant soap and cover with antibacterial cream; seek immediate medical attention
• Inhalation: Move to fresh air; administer artificial respiration or oxygen if needed; seek medical attention
• Serious Inhalation: Loosen clothing, administer oxygen, and seek medical attention
• Ingestion: Do NOT induce vomiting unless instructed by medical personnel; seek immediate medical attention

Exposure Controls & Personal Protection

Engineering Controls

• Use local exhaust ventilation and process enclosures to maintain safe air quality
• Ensure eyewash stations and safety showers are readily accessible

Personal Protection Equipment

• Standard Handling:
  • Splash goggles
  • Lab coat
  • Dust respirator (certified)
  • Gloves
• For Large Spills:
  • Splash goggles
  • Full protective suit
  • Dust respirator
  • Boots and gloves
  • Self-contained breathing apparatus (SCBA)
  • Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.

Regulation

United States

OSHA: The United States Occupational Safety & Health Administration has set an airborne permissible exposure limit (PEL) for calcium cyanamide of 5mg/m³ (as Cyanide) averaged over an 8-hour workshift.

NIOSH: The National Institute for Occupational Safety & Health has set a recommended airborne exposure limit for calcium cyanamide of 0.5mg/m³ averaged over a 10-hour workshift.

ACGIH: The American Conference of Governmental Industrial Hygienists has set a recommended airborne exposure limit for calcium cyanamide of 0.5mg/m³ averaged over an 8-hour workshift.

Australia

Safe Work Australia: Safe Work Australia has set a time weighted average concentration for calcium cyanamide of 0.5mg/m³ averaged over an 8-hour workshift.