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Product name: Calcium Hydroxide
Chemical formula: Ca(OH)₂
Common names: Slaked lime, hydrated lime
Appearance: Fine white powder or colorless crystals
Odor: No noticeable scent
Typical uses: Used in agriculture for soil acidity control, drinking water treatment, construction, food processing, and many other settings
CAS Number: 1305-62-0
Molar mass: 74.09 g/mol
Solubility in water: Moderately soluble, forming a basic solution
Physical hazards: Not combustible, but contact with moisture releases heat
Health risks: Causes severe skin and eye irritation, risk of serious eye damage, inhalation of dust may cause respiratory irritation, ingestion may cause gastrointestinal distress
Long-term effects: Prolonged breathing of dust can lead to chronic respiratory issues; repeat skin contact causes dermatitis
Environmental concerns: Harmful to aquatic life in high concentration due to pH change
Main component: Calcium Hydroxide at a high percentage (close to pure in most cases)
Impurities: Trace amounts of calcium carbonate, calcium oxide, magnesium oxide depending on source minerals and processing
Eye contact: Flush eyes gently with plenty of water for at least 15 minutes, seek medical attention immediately due to threat of permanent damage
Skin contact: Rinse thoroughly with soap and water, remove contaminated clothing, seek care if irritation persists
Inhalation: Move to fresh air, encourage deep breathing, seek care if coughing or shortness of breath develops
Ingestion: Rinse mouth, do not induce vomiting, drink water if person is alert, seek medical attention quickly
Flammability: Non-flammable, does not fuel fire
Explosion risk: None known under normal use, but reactions with acids or moisture can release heat
Extinguishing media: Use extinguishers suitable for surrounding fire, calcium hydroxide does not burn
Firefighting tips: Firefighters should wear appropriate protective gear to avoid dust inhalation and exposure
Personal precautions: Limit exposure to dust with face masks, gloves, goggles, and protective clothing
Containment: Avoid creating dust clouds, sweep up dry material carefully, avoid mixing with acids
Cleanup: Collect using non-sparking, non-combustible tools, place in secure, labeled containers
Environmental protection: Prevent spillage into waterways, avoid run-off into soil where crops or aquatic areas may be affected
Safe handling: Wear personal protective equipment before opening bags or containers, avoid skin and eye contact, never handle with wet hands
Storage conditions: Store in tightly sealed containers or bags, keep in dry and cool areas, avoid exposure to moisture or acids, keep away from food and animal feed
Special storage tips: Ensure easy access to eyewash stations and emergency showers nearby storage points
Incompatibility: Keep away from acids, ammonium salts, and aluminum, as dangerous reactions may occur
Exposure limits: Occupational regulators (like OSHA and ACGIH) set airborne limits for calcium hydroxide dust, generally in the range of 5 mg/m³
Engineering controls: Use local exhaust ventilation, process enclosures to control dust at the source
Personal protective equipment: Choose NIOSH-approved respirators for fine dust, chemical splash goggles for eye protection, gloves and full-coverage clothing for skin protection
Hygiene: Wash hands after handling, don’t eat or drink near work areas, remove contaminated clothing and launder before reuse
Form: White powder, crystalline
Melting point: Decomposes at ~580°C rather than melting
Solubility: Slightly soluble in water, forming a strongly alkaline solution
pH of solution: Alkaline, often about 12.4 in saturated water solution
Odor threshold: Not applicable; no odor
Boiling point: Does not boil, decomposes upon strong heating
Specific gravity: About 2.24 (water = 1)
Vapor pressure: Negligible
Particle size: Fine and lightweight, dust easily becomes airborne
Chemical stability: Stable under recommended storage and handling
Reactivity: Reacts vigorously with acids to form calcium salts and release heat, reacts with moisture to exothermically form calcium hydroxide from calcium oxide, attacks aluminum with hydrogen gas evolution
Conditions to avoid: Exposure to acids generates heat and potentially hazardous gases, excessive humidity or water exposure hardens product and may generate heat
Hazardous decomposition products: No dangerous gases under normal use, with acid produces calcium salts and water, hydrogen could evolve with aluminum
Routes of exposure: Inhalation, skin contact, eye contact, ingestion
Acute effects: Local irritation of skin and mucous membranes, caustic burns on contact, lung irritation with coughing, redness and burning
Chronic effects: Prolonged inhalation causes breathing difficulties and lung inflammation, repeated skin contact causes dermatitis
Toxicity data: Practically nontoxic in low quantities for healthy adults but the caustic alkalinity can injure tissues rapidly
Sensitization: Not generally considered an allergen, injuries relate to physical damage due to alkalinity
Environmental fate: Raises pH of surface waters, risk to aquatic life at high concentrations
Aquatic toxicity: Quickly causes increased alkalinity, affects fish and invertebrate health
Soil impact: Used in controlled amounts to neutralize acidic soils, can change microbial balance if overapplied
Persistence: Not likely to bioaccumulate, disperses with water movement and activity
Degradability: Dissolves and reacts with atmospheric CO₂ over time to form calcium carbonate
Product disposal: Dispose through licensed waste management, treat large amounts as chemical waste, avoid dumping in drains or natural water bodies
Container disposal: Empty containers should be rinsed thoroughly, recycling possible after decontamination
Special notes: Many localities restrict disposal to landfill or sewer, so consult local regulations before disposal
Shipping description: Calcium hydroxide is not regulated as a hazardous material by most transportation authorities for road, rail, or air
Packing needs: Use robust bags or tight drums to prevent dust leakage
Handling in transit: Keep dry during shipping, clearly label to avoid mishandling
Unloading tips: Limit dust exposure for handlers, prepare for cleanup of possible minor spills
Workplace safety: Most countries list it as hazardous due to the caustic properties, requiring proper labeling and worker education
Labeling: Strict hazard labels and warning statements apply in many regions
Environmental rules: Limits on water discharge, dust emissions, and soil application are enforced to protect ecosystems
Consumer regulations: Use in food, water treatment, and construction subject to extra quality and purity controls
Recordkeeping: Safety data, usage logs, and incident records are often mandated in workplaces
