Title: Calcium Hydroxide
CAS Registry Number: 1305-62-0
Synonyms: Calcium hydrate; slaked lime
Molecular Formula: CaH2O2
Molecular Weight: 74.09
Percent Composition: Ca 54.09%, H 2.72%, O 43.19%
Line Formula: Ca(OH)2
Literature References: Contains at least 95% Ca(OH)2. Commercial prepn by hydration of lime: W. L. Faith
et al., Industrial Chemicals (John Wiley, New York, 3rd ed., 1965) pp 483-484. Laboratory prepn by treating an aq soln of a calcium salt with alkali: Ehrlich in
Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer (Academic Press, New York, 2nd ed., 1963) p 934. Toxicity study: Smyth
et al., Am. Ind. Hyg. Assoc. J. 30, 470 (1969).
Properties: Crystals or soft, odorless, granules or powder. Slightly bitter, alkaline taste. Readily absorbs CO2 from air forming CaCO3. Loses water when ignited; forms CaO. d 2.08-2.34. Slightly sol in water; sol in glycerol, sugar or NH4Cl solns; sol in acids with evolution of much heat. pH of aq soln satd at 25°: 12.4.
Keep well closed. LD50 orally in rats: 7.34 g/kg (Smyth).
Density: d 2.08-2.34
Toxicity data: LD50 orally in rats: 7.34 g/kg (Smyth)
CAUTION: Potential symptoms of overexposure are irritation of eyes, skin, upper respiratory system; eye and skin burns; skin vesiculation; cough, bronchitis, pneumonia.
See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 46.
Use: In mortar, plaster, cement and other building and paving materials; in lubricants, drilling fluids, pesticides, fireproofing coatings, water paints; as egg preservative; manuf of paper pulp; in SBR rubber vulcanization; in water treatment; dehairing hides.
Therap-Cat: Astringent.
Keywords: Astringent.
