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
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

Properties.
Formula
CaH2O2
Formula mass
74.10
Melting point, °C
550
Vapor density (air=1)
2.6
Odor Threshold Odor threshold Odorless
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.
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.
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
Hazard class
8
Packing Group
I; II; III
 
USCG CHRIS Code
CAH
 
HS Code
2825 90 19
 
IMO Chemical Code
18
IMO Pollution Category
D