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Sodium hydroxide

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Synonyms & Trade Names
Caustic soda, Lye [Sodium hydroxide], Soda lye, Sodium hydrate
CAS No.
1310-73-2
RTECS No.
WB4900000
DOT ID & Guide
1823 154(dry, solid)
1824 154(solution)
Formula
NaOH
Conversion
IDLH
10 mg/m3
See: 1310732
Exposure Limits
NIOSH REL
C 2 mg/m3
OSHA PEL
TWA 2 mg/m3 See Appendix G
Measurement Methods
NIOSH 7401
See: NMAM or OSHA Methods
Physical Description
Colorless to white, odorless solid (flakes, beads, granular form).
Molecular Weight
40.0
Boiling Point
2534°F
Melting Point
605°F
Solubility
111%
Vapor Pressure
0 mmHg (approx)
Ionization Potential
NA
Specific Gravity
2.13
Flash Point
NA
Upper Explosive Limit
NA
Lower Explosive Limit
NA
Noncombustible Solid, but when in contact with water may generate sufficient heat to ignite combustible materials.
Incompatibilities & Reactivities
Water; acids; flammable liquids; organic halogens; metals such as aluminum, tin & zinc; nitromethane [Note: Corrosive to metals.]
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
irritation eyes, skin, mucous membrane; pneumonitis; eye, skin burns; temporary loss of hair
Target Organs
Eyes, skin, respiratory system
Personal Protection/Sanitation
(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated
Remove:When wet or contaminated
Change:Daily
Provide:Eyewash, Quick drench
First Aid
(See procedures)
Eye:Irrigate immediately
Skin:Water flush immediately
Breathing:Respiratory support
Swallow:Medical attention immediately
Respirator Recommendations

NIOSH/OSHA

Up to 10 mg/m3:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode£/


(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters. 


(APF = 25) Any powered, air-purifying respirator with a high-efficiency particulate filter.£
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator with a full facepiece

Emergency or planned entry into unknown concentrations or IDLH conditions:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:


(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters. 


Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 0360   MEDICAL TESTS: 0210
Page last reviewed: October 30, 2019
Content source: National Institute for Occupational Safety and Health