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OSHA/EPA Occupational Chemical Database

Chemical Identification
Chemical Name: SODIUM HYDROXIDE
CAS #: 1310-73-2 UN No: 1823 Formula: HNaO
Synonyms: Caustic soda; Lye; Soda lye; Sodium hydrate

Physical Properties
Physical Description: Colorless to white, odorless solid (flakes, beads, granular form).
BP: 2534ºF MW: 40.0 LEL: NA NFPA Fire Rating: 0
FRZ/MLT: MLT: 605ºF VP: 0 mmHg (approx) UEL: NA NFPA Health Rating: 3
FP: NA VD: NA NFPA Reactivity Rating: 1
Sp. GR: 2.13 IP: NA NFPA Sp. Inst.: NA

Exposure Limits
OSHA NIOSH Related Information
PEL-TWA ppm: NA REL-TWA ppm: NA AIHA Emergency Response Planning Guidelines - ERPG-1/ERPG-2/ERPG-3:
0.5 mg/m3/5 mg/m3/50 mg/m3
PEL-TWA mg/m3: 2 REL-TWA mg/m3: NA
PEL-STEL ppm: NA REL-STEL ppm: NA
PEL-STEL mg/m3: NA REL-STEL mg/m3: NA
PEL-C ppm: NA REL-C ppm: NA
PEL-C mg/m3: NA REL-C mg/m3: 2 Carcinogen Classifications: NA
Skin Notation: No Skin Notation: No
Notes: NA Notes: NA

IDLH ppm: NA

IDLH mg/m3: 10

IDLH Notes: NA

NIOSH Pocket Guide to Chemical Hazards (Current through June 2006)
Sodium hydroxide CAS: 1310-73-2
Formula: 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 Conversion: NA
Physical Description
Colorless to white, odorless solid (flakes, beads, granular form). 
MW: 40.0 BP: 2534F MLT: 605F Sol: 111%
VP: 0 mmHg (approx) IP: NA RGasD: NA Sp.Gr: 2.13
Fl.P: NA UEL: NA LEL: NA MEC: NA
Noncombustible Solid, but when in contact with water may generate sufficient heat to ignite combustible materials. (See flammable and combustible liquid classes)
Incompatibilities & Reactivities
Water; acids; flammable liquids; organic halogens; metals such as aluminum, tin & zinc; nitromethane [Note: Corrosive to metals.]
Measurement Methods
NIOSH 7401
Personal Protection & Sanitation First Aid
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contam
Remove: When wet or contam
Change: Daily
Provide: Eyewash, Quick drench
Eye: Irr immed
Skin: Water flush immed
Breath: Resp support
Swallow: Medical attention immed
(See procedures)
NIOSH Respirator Recommendations
NIOSH/OSHA 10 mg/m3: SA:CF/HiEF/PAPRDM/SCBAF/SAF : SCBAF:PD,PP/SAF:PD,PP:ASCBA Escape: HiEF/SCBAE
(See symbols and codes)
Exposure Routes
Inh Ing Con
Symptoms
Irrit eyes, skin, muc memb; pneuitis; eye, skin burns; temporary loss of hair
(See abbreviations)
Target Organs
Eyes, skin, resp sys
(See abbreviations)

DOT Emergency Response Guidebook (ERG 2004)
Guide Number: 154
154 Substances - Toxic and/or Corrosive (Non-Combustible)
POTENTIAL HAZARDS
HEALTH
*       TOXIC; inhalation, ingestion, or skin contact with material may cause
        severe injury or death.
*       Contact with molten substance may cause severe burns to skin and eyes.
*       Avoid any skin contact.
*       Effects of contact or inhalation may be delayed.
*       Fire may produce irritating, corrosive and/or toxic gases.
*       Runoff from fire control or dilution water may be corrosive and/or
        toxic and cause pollution.
FIRE OR EXPLOSION
*       Non-combustible, substance itself does not burn but may decompose upon
        heating to produce corrosive and/or toxic fumes.
*       Some are oxidizers and may ignite combustibles (wood, paper, oil,
        clothing, etc.).
*       Contact with metals may evolve flammable hydrogen gas.
*       Containers may explode when heated.
PUBLIC SAFETY
*       CALL Emergency Response Telephone Number on Shipping Paper first. If
        Shipping Paper not available or no answer, refer to appropriate
        telephone number listed on the inside back cover.
*       Isolate spill or leak area immediately for at least 25 to 50 meters
        (80 to 160 feet) in all directions.
*       Keep unauthorized personnel away.
*       Stay upwind.
*       Keep out of low areas.
*       Ventilate enclosed areas.
PROTECTIVE CLOTHING
*       Wear positive pressure self-contained breathing apparatus (SCBA).
*       Wear chemical protective clothing which is specifically recommended by
        the manufacturer. It may provide little or no thermal protection.
*       Structural firefighters' protective clothing provides limited
        protection in fire situations ONLY; it is not effective in spill
        situations.
EVACUATION
Spill
*       See the Table of Initial Isolation and Protective Action Distances for
        highlighted substances. For non-highlighted substances, increase, in
        the downwind direction, as necessary, the isolation distance shown
        under PUBLIC SAFETY.
Fire
*       If tank, rail car or tank truck is involved in a fire, ISOLATE for
        800 meters (1/2 mile) in all directions; also, consider initial
        evacuation for 800 meters (1/2 mile) in all directions.
EMERGENCY RESPONSE
FIRE
Small Fires
*       Dry chemical, CO2 or water spray.
Large Fires
*       Dry chemical, CO2, alcohol-resistant foam or water spray.
*       Move containers from fire area if you can do it without risk.
*       Dike fire control water for later disposal; do not scatter the
        material.
Fire involving Tanks or Car/Trailer Loads
*       Fight fire from maximum distance or use unmanned hose holders or
        monitor nozzles.
*       Do not get water inside containers.
*       Cool containers with flooding quantities of water until well after
        fire is out.
*       Withdraw immediately in case of rising sound from venting safety
        devices or discoloration of tank.
*       ALWAYS stay away from tanks engulfed in fire.
SPILL OR LEAK
*       ELIMINATE all ignition sources (no smoking, flares, sparks or flames
        in immediate area).
*       Do not touch damaged containers or spilled material unless wearing
        appropriate protective clothing.
*       Stop leak if you can do it without risk.
*       Prevent entry into waterways, sewers, basements or confined areas.
*       Absorb or cover with dry earth, sand or other non-combustible material
        and transfer to containers.
*       DO NOT GET WATER INSIDE CONTAINERS.
FIRST AID
*       Move victim to fresh air.
*       Call 911 or emergency medical service.
*       Apply artificial respiration if victim is not breathing.
*       Do not use mouth-to-mouth method if victim ingested or inhaled the
        substance; induce artificial respiration with the aid of a pocket mask
        equipped with a one-way valve or other proper respiratory medical
        device.
*       Administer oxygen if breathing is difficult.
*       Remove and isolate contaminated clothing and shoes.
*       In case of contact with substance, immediately flush skin or eyes with
        running water for at least 20 minutes.
*       For minor skin contact, avoid spreading material on unaffected skin.
*       Keep victim warm and quiet.
*       Effects of exposure (inhalation, ingestion or skin contact) to
        substance may be delayed.
*       Ensure that medical personnel are aware of the material(s) involved,
        and take precautions to protect themselves.

Additional Emergency Response Information (CAMEO Data)
Non-fire Spill Response: Keep material out of water sources and sewers. Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Water spill: Neutralize with dilute acid. ( AAR, 1999)
Firefighting: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Apply water from as far a distance as possible. ( AAR, 1999)
Reactivity: AIR AND WATER REACTIONS: Hydrolysis generates enough heat to ignite adjacent combustible material (Haz. Chem. Data 1966). Dissloves in water with liberation of heat, may steam and spatter. Solution is basic (alkaline).CHEMICAL PROFILE: Absorbs moisture readily forming caustic soln. which attacks aluminum and zinc. A violent polymerization of acetaldehyde results from the reactions of acetaldehyde with alkaline materials such as sodium hydroxide. Calcium oxide or sodium hydroxide react with phosphorus pentoxide extremely violently when initiated by local heating (Mellor 8 Supp.3:406 1971). Using potassium hydroxide to dry impure tetrahydrofuran, which contains peroxides, may be hazardous. Explosions have occurred in the past. Sodium hydroxide behaves in a similar way as potassium hydroxide (NSC Newsletter Chem. Soc. 1967). Mixing sodium hydroxide in equal portions with any of the following substances in a closed container caused the temperature and pressure to increase: glacial acetic acid, acetic anhydride, acrolein, chlorohydrin, chlorosulfonic acid, ethylene cyanohydrin, glyoxal, hydrochloric acid (36%), hydrofluoric acid (48.7%), nitric acid (70%), oleum, propiolactone, sulfuric acid (96%) (NFPA 1991). An extremely violent polymerization reaction of acrolein results from the contact with alkaline materials such as sodium hydroxide (Chem. Safety Data Sheet SD-85 1961). Alkali and other alkaline earth compounds such as potassium, lithium, calcium, barium, and magnesium compounds, as well as amines and other nitrogen compounds will cause explosive decomposition of maleic anhydride (MCA Case History 622 1960). Pentol, being fractionated under high vacuum, was accidentally contacted by caustic cleaning solution and a violent explosion resulted, MCA Case History 363(1964). In the manufacture of sodium salt of trichlorophenol, sodium hydroxide, methyl alcohol and trichlorobenzene were heated. During the heating process, the pressure suddenly increased rapidly and an explosion occurred (MCA Guide for Safety Appendix 3 1972). (REACTIVITY, 1999)
First Aid: Eye: If this chemical contacts the eyes, immediately wash the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Contact lenses should not be worn when working with this chemical. Skin: If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly. Breathing: If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform mouth-to-mouth resuscitation. Keep the affected person warm and at rest. Get medical attention as soon as possible. Swallow: If this chemical has been swallowed, get medical attention immediately. (NIOSH, 1997)




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