NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Sodium hydroxide

CAS
1310-73-2

NaOH

RTECS
WB4900000
Synonyms & Trade Names

Caustic soda, Lye, Soda lye, Sodium hydrate
DOT ID & Guide
1823 / 154 (dry, solid)
1824 / 154 (solution)

Exposure
Limits

NIOSH REL: C 2 mg/m3
OSHA PEL: TWA 2 mg/m3
IDLH
10 mg/m3 See: 1310732
Conversion
Physical Description
Colorless to white, odorless solid (flakes, beads, granular form).
MW: 40.0
BP: 2534°F
MLT: 605°F
Sol: 111%
VP: 0 mmHg (approx)
IP: NA

Sp.Gr: 2.13
Fl.P: NA
UEL: NA
LEL: 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.]
Measurement Methods
NIOSH 7401
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
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
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
See also: INTRODUCTION   See ICSC CARD: 0360   See MEDICAL TESTS: 0210