Calcium hydroxide

  • Calcium dihydroxide
  • Calcium hydrate
  • Hydrated lime
  • Slaked lime
Formula Ca(OH)2
Structure
Description White crystals or soft powder or granules, impure material has gray or buff color, odorless, readily absorbs carbon dioxide from the air to form calcium carbonate.
Uses In lubricants, drilling fluid, pesticides, fireproofing coatings, water paint, as egg preservative, manufacture of paper pulp, in SBR rubber vulcanization, dehairing hides, in water treatment, in mortar, plaster, cement and other binding and paving materials.

Registry Numbers and Inventories.
CAS 1305-62-0
EC (EINECS/ELINCS) 215-137-3
EC Class irritant
EC Risk Phrase R 34
EC Safety Phrase S 26 36/37/39 45
RTECS EW2800000
RTECS class Agricultural Chemical and Pesticide; Mutagen; Primary Irritant
UN (DOT) 1759
Merck 13,1675
Beilstein/Gmelin 8815
EPA OPP 75601
Swiss Giftliste 1 G-1012
Canada DSL/NDSL DSL
US TSCA Listed
Austrailia AICS Listed
New Zealand Listed
Japan ENCS (MITI) Listed
Korea ECL Listed

Odor Threshold Odor threshold Odorless
Properties.
Formula CaH2O2
Formula mass 74.10
Melting point, °C 550
Vapor density (air=1) 2.6
Density 2.24 g/cm3
Solubility in water 0.18 g /100 ml
Refractive index 1.555
Thermal expansion 3.14E5/K (25 C)

Hazards and Protection.
Storage Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Corrosives area. Do not exceed 25-30C.
WHMIS E.
Handling Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Keep container tightly closed. Do not get on skin or in eyes. Do not ingest or inhale. Use only in a chemical fume hood.
Protection Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal. Avoid generating dusty conditions.
Disposal code 14
Stability Stable at room temperature in closed containers under normal storage and handling conditions. Readily absorbs carbon dioxide from air forming calcium carbonate.
Incompatibilities Phosphorus, maleic anhydride, nitromethane, nitroethane, nitroparaffins, nitropropane, polychlorinated phenols + postassium nitrate.
Decomposition Calcium oxide, forms chlorinated benzodioxins when mixed with polychlorinated phenols and potassium nitrate.

Fire.
Fire fighting Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Substance is nonflammable. Runoff from fire control or dilution water may cause pollution. Extinguishing media: Use dry chemical.
Fire potential Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Hazards Contact with metals may evolve flammable hydrogen gas.
Combustion products Fire may produce irritating, corrosive and/or toxic gases.
NFPA Health 3
  Flammability 0  
  Reactivity 0  

Health.
Exposure limit(s) TLV: 5 ppm; mg/m3 (ACGIH 1996). OSHA PEL: TWA 15 mg/m3 (total) 5 mg/m3 (resp) NIOSH REL: TWA 5 mg/m3
Poison_Class 4
Exposure effects Prolonged or repeated skin contact may cause dermatitis. Chronic inhalation and ingestion may cause effects similar to those of acute inhalation and ingestion. Prolonged or repeated exposure may cause corneal damage and the development of cataracts and glaucoma.
   Ingestion Causes gastrointestinal tract burns. May cause circulatory system failure. May cause perforation of the digestive tract. Causes severe pain, nausea, vomiting, diarrhea, and shock. Effects may be delayed.
   Inhalation Inhalation may be fatal as a result of spasm, inflammation, edema of the larynx and bronchi, chemical pneumonitis and pulmonary edema. Inhalation may produce burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea, and vomiting. Causes irritation of the mucous membrane and upper respiratory tract.
   Skin Causes severe skin irritation and burns. May be harmful if absorbed through the skin.
   Eyes May result in corneal injury. Contact with liquid or vapor causes severe burns and possible irreversible eye damage. May cause temporary corneal clouding.

First aid
 
   Ingestion Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Do not use mouth-to-mouth respiration if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device.
   Skin Get medical aid immediately. Wash clothing before reuse. Rinse area with large amounts of water for at least 15 minutes. Remove contaminated clothing and shoes.
   Eyes Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed.

Transport.
UN number 1759
Response guide 154
Hazard class 8
Packing Group I; II; III  
USCG CHRIS Code CAH  
USCG Compatatibility Group 5 Caustics
HS Code 2825 90 19  
IMO Chemical Code 18
IMO Pollution Category D