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Calcium hydroxide

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Synonyms & Trade Names
Calcium hydrate, Caustic lime, Hydrated lime, Slaked lime
CAS No.
1305-62-0
RTECS No.
EW2800000
DOT ID & Guide
Formula
Ca(OH)₂
Conversion
IDLH
N.D.
See: IDLH INDEX
Exposure Limits
NIOSH REL
TWA 5 mg/m3
OSHA PEL
TWA 15 mg/m3 (total) 5 mg/m3 (resp)
Measurement Methods
NIOSH 7020;
OSHA ID121
See: NMAM or OSHA Methods
Physical Description
White, odorless powder. [Note: Readily absorbs CO2 from the air to form calcium carbonate.]
Molecular Weight
74.1
Boiling Point
Decomposes
Melting Point
1076°F (Decomposes) (Loses H2O)
Solubility
(32°F): 0.2%
Vapor Pressure
0 mmHg (approx)
Ionization Potential
NA
Specific Gravity
2.24
Flash Point
NA
Upper Explosive Limit
NA
Lower Explosive Limit
NA
Noncombustible Solid
Incompatibilities & Reactivities
Maleic anhydride, phosphorus, nitroethane, nitromethane, nitroparaffins, nitropropane [Note: Attacks some metals.]
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
irritation eyes, skin, upper respiratory system; eye, skin burns; skin vesiculation; cough, bronchitis, pneumonitis
Target Organs
Eyes, skin, respiratory system
Personal Protection/Sanitation
(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated/Daily
Remove:When wet or contaminated
Change:Daily
Provide:Eyewash, Quick drench
First Aid
(See procedures)
Eye:Irrigate immediately
Skin:Soap flush immediately
Breathing:Respiratory support
Swallow:Medical attention immediately
Respirator Recommendations

Not available.

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 0408
Page last reviewed: October 30, 2019
Content source: National Institute for Occupational Safety and Health