More than 60 people, primarily children, were hospitalized in Bhopal following severe injuries sustained from the use of makeshift “calcium carbide guns” during Diwali celebrations.
About Calcium Carbide

• Calcium carbide (CaC2) is a chemical compound primarily used industrially for producing acetylene gas (C2H2) and calcium cyanamide.
• It appears as gray or brown lumps or crystalline powder with a garlic-like odor, especially in technical-grade form containing impurities like calcium oxide and calcium phosphide.
• Pure calcium carbide itself is colorless and crystalline.
• It is produced industrially by heating a mixture of coke (carbon) and lime (calcium oxide) in an electric furnace at high temperatures around 2200 °C.
• Calcium carbide reacts with water to release acetylene gas, which historically has been used in carbide lamps for lighting and is still important as a precursor in chemical synthesis.

Applications include:

• Manufacture of acetylene gas for welding and cutting metals.
• Steelmaking and metal desulfurization.
• Production of chemicals including calcium cyanamide used as fertilizer.
• Fruit ripening agent (though with health concerns).
• Catalyst in organic synthesis and waste rubber degradation.
• Handling needs caution as it reacts violently with water releasing flammable acetylene and has health hazards including irritation on contact.

Key properties:

• Chemical formula: CaC2
• Molar mass: 64.1 g/mol
• Melting point: About 2160 °C
• Boiling point: About 2300 °C
• Density: ~2.22 g/cm³

Calcium carbide thus serves as a versatile industrial chemical with significant utility in manufacturing, agriculture, and metalworking sectors but requires safety measures during handling due to its reactive nature and toxicity risks from impurities.
Calcium Carbide Health Impacts
Calcium carbide poses serious health risks, primarily due to the toxic impurities it often contains and the hazardous acetylene gas it produces when mixed with moisture. Used illegally to ripen fruit, calcium carbide has been linked to neurological damage, gastrointestinal problems, and an increased risk of cancer from contaminants. 
Short-term and immediate health effects
Exposure to calcium carbide can lead to both immediate and acute health issues: 

• Gastrointestinal distress: Consumption of fruits ripened with calcium carbide can cause stomach irritation, leading to abdominal pain, nausea, vomiting, and diarrhea. The chemical erodes the mucosal tissues of the stomach and can disrupt intestinal function.
• Respiratory problems: Inhaling acetylene gas, released when calcium carbide reacts with moisture, can irritate the respiratory system, causing coughing, wheezing, and shortness of breath. High levels of exposure can lead to pulmonary edema (fluid buildup in the lungs), a serious medical emergency.
• Neurological symptoms: Acetylene gas can cause prolonged hypoxia (oxygen deprivation), which may trigger headaches, dizziness, sleepiness, mood disturbances, confusion, and memory loss. In severe cases, it can cause cerebral edema (brain swelling) and seizures.
• Skin and eye irritation: Direct contact with the chemical can cause skin irritation, rashes, burns, and a burning sensation. If it contacts the eyes, it can cause redness, severe pain, and deep burns, with potential for permanent damage. 

Long-term health effects
Repeated or chronic exposure to calcium carbide, particularly through contaminated food, has been associated with more severe, long-term health consequences: 

• Cancer: Commercial-grade calcium carbide often contains traces of arsenic and phosphorus. Arsenic is a known carcinogen linked to an increased risk of cancer, especially of the skin, lungs, liver, and bladder.
• Organ damage: Chronic exposure to the arsenic and phosphorus found in calcium carbide can cause damage to the liver and kidneys.
• Neurological disorders: Long-term exposure to the neurotoxic compounds can lead to lasting neurological issues and impaired cognitive function. Animal studies have also demonstrated damage to the nervous system.
• Chronic respiratory issues: Continuous inhalation of acetylene gas can cause chronic bronchitis and other lung damage. 

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