Calcium oxide

  • Quicklime
  • Lime
  • Burnt lime
  • Lime, unslaked
Formula
CaO
Structure
Description
White, greyish-white, pale yellow or pale gray lumps or granular powder. Commercial grade has a yellowish or brownish tint, due to the presence of iron.
Uses
In construction applications incl finishing & masons lime, in metallurgy, princpl as a flux in steel prodn, kraft paper pulp prodn, ammonia recovery in solvay process for sodium carbonate, treatment of sewage and trade waste, water purification and softening, misc applications.

Registry Numbers and Inventories.
CAS
1305-78-8
EC (EINECS/ELINCS)
215-138-9
EC Class
irritant
R 34 41
S 22 26 36/37/39 45
RTECS
EW3100000
RTECS class
Other
UN (DOT)
1910
Merck
13,1691
Beilstein/Gmelin
13649 (G)
EPA OPP
75604
Swiss Giftliste 1
G-1351
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
CaO
Formula mass
56.08
Melting point, °C
2580
Boiling point, °C
2850
Vapor pressure, mmHg
1.8E-6 (1455 C)
Vapor density (air=1)
1.9
Evaporization number
Not volatile
Odor Threshold Odor threshold Odorless
Density
3.38 g/cm3
Solubility in water
Reacts
Thermal expansion
3.92E-05 - 6.73E-05/K
Heat of fusion
53.78 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Do not store near combustible materials. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep away from water. Corrosives area. Store in glass containers.
E.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Minimize dust generation and accumulation. Keep container tightly closed. Avoid contact with clothing and other combustible materials. Do not get on skin or in eyes. Avoid ingestion and inhalation.
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 gloves to prevent skin exposure. Clothing: Wear a chemical apron. Wear appropriate clothing to prevent skin exposure.
Respirators
Wear a NIOSH/MSHA or European Standard EN 149 approved full-facepiece airline respirator in the positive pressure mode with emergency escape provisions.
Small spills/leaks
Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Remove all sources of ignition. Provide ventilation.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Reducing agents.
Decomposition
Irritating and toxic fumes and gases.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Strong oxidizer. Contact with combustible materials may cause a fire. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Substance is nonflammable. Use water with caution and in flooding amounts. Reacts violently with water. Extinguishing media: Use water spray to cool fire-exposed containers. Do NOT use carbon dioxide. Use extinguishing media most appropriate for the surrounding fire. Do NOT use halogenated agents. Use flooding quantities of water. Contact professional fire-fighters immediately.
Fire potential
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Hazards
Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars, etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases. Reaction with water may generate much heat which will increase the concentration of fumes in the air. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.
Combustion products
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Health
3
 
Flammability
0
 
 
Reactivity
1
 

Health.
Exposure limit(s)
TLV: 2 ppm; mg/m3 (ACGIH 1996). MAK: 5 ppm; mg/m3; (1996). OSHA PEL: TWA 5 mg/m3 NIOSH REL: TWA 2 mg/m3 NIOSH IDLH: 25 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. Repeated inhalation may cause perforation of the nasal septum.
   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.
   Inhalation
Causes respiratory tract irritation. May cause chemical bronchitis with coughing and difficulty in breathing. May cause acute pulmonary edema, asphyxia, chemical pneumonitis, and upper airway obstruction caused by edema.
   Skin
Contact with skin causes irritation and possible burns, especially if the skin is wet or moist. May cause deep, penetrating ulcers of the skin.
   Eyes
May result in corneal injury. Contact with liquid or vapor causes severe burns and possible irreversible eye damage. May cause conjunctivitis. May cause permanent corneal opacification.

First aid
 
   Ingestion
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. 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.
   Skin
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. 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
1910
Response guide
Hazard class
8
Packing Group
III
 
USCG CHRIS Code
CAO
 
HS Code
2825 90 19
 
Std. Transport #
4936357