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| SECTION 1. CHEMICAL IDENTIFICATION |
 Appearance and Odour:
- White,
odourless, non-volatile pellets, flakes, beads, chips, sticks, lumps or
solid cake. Deliquescent (absorbs moisture from the air and forms wet
solutions).(3,21,25)
- Odour Threshold:
- Odourless (3)
- Warning Properties:
- POOR - sodium hydroxide has no odour.
- Composition/Purity:
- Sodium
hydroxide is produced mainly in three forms: 50% and 73% aqueous
solutions, and anhydrous sodium hydroxide in the form of solid cakes,
flakes or beads. The major impurities include sodium chloride, sodium
carbonate, sodium sulfate, sodium chlorate, potassium and heavy metals
such as iron and nickel.(25,35) This record reviews the information
relevant to the solid form. CHEMINFO record 5 reviews information
relevant to solutions.
- Uses and Occurrences:
- The
main uses of sodium hydroxide are in chemical manufacturing (pH
control, acid neutralization, off-gas scrubbing and catalyst); pulp and
paper manufacturing; in petroleum and natural gas industry (removing
acidic contaminants in oil and gas processing); manufacture of soap and
detergents and other cleaning products; and cellulosics, such as rayon,
cellophane and cellulose ethers; cotton mercerizing and scouring. Other
uses include water treatment, food processing, flue-gas scrubbing,
mining, glass making, textile processing, refining vegetable oils,
rubber reclamation, metal processing, aluminum processing, metal
degreasing, adhesive preparations, paint remover, disinfectant, rubber
latex stabilizer and stabilization of sodium hypochlorite.(25,35)
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| SECTION 3. HAZARDS IDENTIFICATION |
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- EMERGENCY OVERVIEW:
- White,
odourless, non-volatile solid. Commonly used as clear solution.
Deliquescent. Will not burn. Highly reactive. Can react violently with
water and numerous commonly encountered materials, generating enough
heat to ignite nearby combustible materials. Contact with many organic
and inorganic chemicals may cause fire or explosion. Reaction with
metals releases flammable hydrogen gas. EXTREMELY CORROSIVE. Can cause
blindness, permanent scarring and death. Aerosols can cause lung
injury--effects may be delayed.
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Effects of Short-Term (Acute) Exposure
- Inhalation:
- Sodium
hydroxide does not readily form a vapour and inhalation exposure is
only likely to occur to aerosols since the solid is deliquescent and
not likely to form a dust. Three case reports suggest that sodium
hydroxide aerosols may cause severe irritation of the respiratory
tract. In one case, permanent lung injury resulted. Due to its
corrosive nature, sodium hydroxide aerosols could cause pulmonary edema
(severe, life-threatening lung injury).
A worker, exposed to hot
mists of sodium hydroxide in a confined space, experienced tightness of
chest, dyspnea (difficult breathing) and cough during each exposure.
The symptoms resolved when exposure stopped.(32) Irreversible
obstructive lung disease resulted when an individual applied about 5 L
of a 5% sodium hydroxide solution with a brush in a small room with
very limited ventilation.(33) Severe lung injury occurred in a man who
inhaled an aerosol given off when water was poured on sodium hydroxide
pellets.(18)
- Skin Contact:
- Sodium
hydroxide is extremely corrosive and is capable of causing severe burns
with deep ulceration and permanent scarring. It can penetrate to deeper
layers of skin and corrosion will continue until removed. The severity
of injury depends on the concentration (solutions) and the duration of
exposure. The solid absorbs moisture from the skin, air and water used
for removal and can also cause severe burns. Burns may not be
immediately painful; onset of pain may be delayed minutes to hours.
Several
human studies and case reports describe the corrosive effects of sodium
hydroxide. A 4% solution of sodium hydroxide, applied to a volunteer's
arm for 15 to 180 minutes, caused damage which progressed from
destruction of cells of the hard outer layer of the skin within 15
minutes to total destruction of all layers of the skin in 60
minutes.(6) Solutions as weak as 0.12% have damaged healthy skin within
1 hour.(5) Sodium hydroxide dissolved the hair and caused reversible
baldness and scalp burns when a concentrated solution (pH = 13.5)
dripped onto a worker's head and treatment was delayed for several
hours.(7)
- Eye Contact:
- Sodium
hydroxide is extremely corrosive. The severity of injury increases with
the concentration (for solutions), the duration of exposure, and the
speed of penetration into the eye. The solid will absorb moisture from
the eye, or water being used for removal, forming a highly concentrated
solution. Damage can range from severe irritation and mild scarring to
blistering, disintegration, ulceration, severe scarring and clouding.
Conditions which affect vision such as glaucoma and cataracts are
possible late developments. In severe cases, there is progressive
ulceration and clouding of eye tissue which may lead to permanent
blindness.(8,9,10,11)
- Ingestion:
- There
are no reported cases of industrial workers ingesting sodium hydroxide.
Non-occupational ingestion has produced severe corrosive burns to the
esophageal tissue, which has in some cases progressed to stricture
formation. Should ingestion occur, severe pain; burning of the mouth,
throat and esophagus; vomiting; diarrhea; collapse and possible death
may result.
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Effects of Long-Term (Chronic) Exposure
- SKIN: Owing to its corrosive
nature, repeated or prolonged skin contact would be expected to cause
drying, cracking, and inflammation of the skin (dermatitis).
INHALATION:
A worker, exposed for 2 hours daily over 20 years to mists from boiling
a solution of sodium hydroxide in 2 large containers in a small room
with inadequate ventilation, developed severe obstructive airway
disease. It was concluded that the massive and prolonged exposure
induced irritation and burns to the respiratory system eventually
leading to the disease. The authors noted that chronic exposure had not
previously been reported, probably since the strong and immediate
irritation would normally deter workers from further exposure.(32)
Actual exposures to sodium hydroxide aerosols were not measured and the
authors could not definitely exclude late onset asthma as a cause of
the man's condition.
A report of workers exposed to sodium hydroxide
aerosol for at least 16 months, was confounded by the presence of high
concentrations of Stoddard solvent and other solvent vapours, as well
as other chemicals.(2,4)
There was no trend of increased mortality
in relation to duration (up to 30 years) or intensity of exposure (0.5
mg/m3 to 1.5 mg/m3) among 291 workers exposed to sodium hydroxide dust
during the production of flakes or beads of concentrated sodium
hydroxide from chlorine cell effluent.(12) This study is limited by the
small population size.
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- Carcinogenicity:
-
- Sodium
hydroxide has been implicated as a cause of cancer of the esophagus in
individuals who have ingested it. The cancer may develop 12 to 42 years
after the ingestion incident. Similar cancers have been observed at the
sites of severe thermal burns. These cancers may be due to tissue
destruction and scar formation rather than the sodium hydroxide
itself.(15,16,17)
A case-control study reported an association
between renal cancer and history of employment in the cell maintenance
area of chlorine production. The major exposures in this work were
presumed to be to asbestos and sodium hydroxide. An association was
made between renal cancer and sodium hydroxide exposure.(34) This study
is limited by factors such as small numbers of exposed workers,
multiple exposures, reliance on work histories and is not considered
sufficiently reliable.
-
- The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.
-
- The
American Conference of Governmental Industrial Hygienists (ACGIH) has
not assigned a carcinogenicity designation to this chemical.
-
- The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.
- Teratogenicity and Embryotoxicity:
- There is no human or animal information available.
- Reproductive Toxicity:
- There is no human or animal information available.
- Mutagenicity:
- There
are no reports of human or animal in vivo studies available. Short-term
testing (in vitro and bacterial) suggests that sodium hydroxide is not
mutagenic.
- Toxicologically Synergistic Materials:
- No information available.
- Potential for Accumulation:
- Does not accumulate.
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| SECTION 4. FIRST AID MEASURES |
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- Inhalation:
- Remove
source of contamination or move victim to fresh air. If breathing is
difficult, oxygen may be beneficial if administered by trained
personnel, preferably on a doctor's advice. DO NOT allow victim to move
about unnecessarily. Symptoms of pulmonary edema can be delayed up to
48 hours after exposure. Immediately transport victim to an emergency
care facility.
- Skin Contact:
- Avoid
direct contact with this chemical. Wear chemical protective clothing,
if necessary. Quickly and gently blot or brush away excess chemical. As
quickly as possible, remove contaminated clothing, shoes and leather
goods (e.g. watchbands, belts). Flush contaminated area with lukewarm,
gently flowing water for at least 60 minutes, by the clock. DO NOT
INTERRUPT FLUSHING. If necessary, keep emergency vehicle waiting.
Transport victim to an emergency care facility immediately. Discard
contaminated clothing, shoes and leather goods.
- Eye Contact:
- Avoid
direct contact. Wear chemical protective gloves, if necessary. Quickly
and gently blot or brush away excess chemical. Immediately flush the
contaminated eye(s) with lukewarm, gently flowing water for at least 60
minutes, by the clock, while holding the eyelid(s) open. Neutral saline
solution may be used as soon as it is available. DO NOT INTERRUPT
FLUSHING. If necessary, keep emergency vehicle waiting. Take care not
to rinse contaminated water into the unaffected eye or onto the face.
Quickly transport victim to an emergency care facility.
- Ingestion:
- NEVER
give anything by mouth if victim is rapidly losing consciousness, is
unconscious or convulsing. Have victim rinse mouth thoroughly with
water. DO NOT INDUCE VOMITING. Have victim drink 240 to 300 mL (8 to 10
oz.) of water to dilute material in stomach. If milk is available, it
may be administered AFTER the water has been given. If vomiting occurs
naturally, repeat administration of water. Quickly transport victim to
an emergency care facility.
- First Aid Comments:
- Provide
general supportive measures (comfort, warmth, rest). Consult a doctor
and/or the nearest Poison Control Centre for all exposures except minor
instances of inhalation contact.
Some recommendations in the above
sections may be considered medical acts in some jurisdictions. These
recommendations should be reviewed with a doctor and appropriate
delegation of authority obtained, as required.
All first aid
procedures should be periodically reviewed by a doctor familiar with
the material and its conditions of use in the workplace.
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| SECTION 5. FIRE FIGHTING MEASURES |
- Flash Point:
- Not combustible (does not burn)
- Lower Flammable (Explosive) Limit (LFL/LEL):
- Not applicable
- Upper Flammable (Explosive) Limit (UFL/UEL):
- Not applicable
- Autoignition (Ignition) Temperature:
- Not applicable
- Sensitivity to Mechanical Impact:
- Not sensitive; stable material.
- Sensitivity to Static Charge:
- Not applicable. Not combustible.
- Combustion and Thermal Decomposition Products:
- Sodium oxide fumes can be generated by thermal decomposition at elevated temperatures.(25)
- Fire Hazard Summary:
- Sodium
hydroxide will not burn or support combustion. However, reaction of
sodium hydroxide with water and a number of commonly encountered
materials (see Chemical Reactivity) can generate sufficient heat to
ignite nearby combustible materials. Sodium hydroxide can react with
metals, such as aluminum, tin and zinc, to form flammable hydrogen gas.
- Extinguishing Media:
- Use
extinguishing media suitable for the surrounding fire. If water is
used, care should be taken, since it can generate heat and cause
spattering if applied directly to sodium hydroxide.
| NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) HAZARD IDENTIFICATION |
| NFPA - Health: |
3 - Short exposure could cause serious temporary or residual injury. |
| NFPA - Flammability: |
0 - Will not burn under typical fire conditions. |
| NFPA - Instability: |
1
- Normally stable, but can become unstable at elevated temperatures and
pressures, or may react vigorously, but non-violently with water. |
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| SECTION 6. ACCIDENTAL RELEASE MEASURES |
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- Spill Precautions:
- Restrict access to area. Provide adequate protective equipment and ventilation.
Remove chemicals which can react with the spilled material.
Notify occupational health and safety and environmental authorities.
- Clean-up:
- Contain
spill or leak. Do not allow entry into sewers or waterways. Shovel or
sweep up dry sodium hydroxide for recycling or disposal. Neutralize the
final traces and flush area with water.
Solutions should be
contained by diking with inert material, such as sand or earth.
Solutions can be recovered or carefully diluted with water and
cautiously neutralized with acids such as acetic acid or hydrochloric
acid.
Large spills: contact fire and emergency services and supplier for advice.
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| SECTION 7. HANDLING AND STORAGE |
- Handling:
- This
material is EXTREMELY CORROSIVE. Before handling, it is very important
that engineering controls are operating and that protective equipment
requirements and personal hygiene measures are being followed. People
working with this chemical should be properly trained regarding its
hazards and its safe use.
Use the smallest possible amounts in an
area separate from the storage area. Immediately report leaks, spills
or failures of the engineering controls. Inspect containers for damage
or leaks before handling. Use the type of containers recommended by the
manufacturer.
Unprotected persons should avoid all contact with this
chemical including contaminated equipment. Do not use with incompatible
materials such as strong acids, nitroaromatic, nitroparaffinic or
organohalogen compounds. See Incompatibilities - Materials to Avoid
section for more information.
Avoid generating dusts. Prevent the
release of dusts into the workplace air. Transfer solids using tools or
equipment which are corrosion-resistant. Cautiously, transfer into
sturdy containers made of compatible materials. Never return
contaminated material to its original container.
Never add water to
a corrosive. Always add corrosives to water. When mixing with water,
stir small amounts in slowly. Use cold water to prevent excessive heat
generation. In general, keep solid sodium hydroxide away from water.
Post "DO NOT USE WATER" signs in area of use to prevent accidental
contact.
Label containers. Avoid damaging containers. Keep
containers tightly closed when not in use. Follow handling precautions
on Material Safety Data Sheet. Have suitable emergency equipment for
fires, spills and leaks readily available. Practice good housekeeping.
Maintain handling equipment. Comply with applicable regulations.
- Storage:
- Store in a cool, dry, well-ventilated area. Keep quantity stored as small as possible.
Store
away from incompatible materials such as strong acids, nitroaromatic,
nitroparaffinic or organohalogen compounds. Take measures to ensure
storage area cannot be contaminated with water. See Incompatibilities -
Materials to Avoid section for more information.
Inspect all
incoming containers to make sure they are properly labelled and not
damaged. Always store in original labelled container, or in the type of
container recommended by the manufacturer/supplier. Protect the label
and keep it visible. Keep containers tightly closed when not in use and
when empty. Protect from damage.
Storage area should be clearly
identified, clear of obstruction and accessible only to trained and
authorized personnel. Keep storage area separate from work areas. Post
warning signs. Inspect periodically for damage or leaks. Floors should
be watertight and without cracks.
Have appropriate fire
extinguishers and spill clean-up equipment in storage area. Follow any
special instructions for storage on Material Safety Data Sheet (e.g.
maximum storage quantities).
Keep empty containers in separate storage area. Empty containers may contain hazardous residues. Keep closed.
Avoid
any dust build-up by frequent cleaning and suitable construction of
storage area. Provide raised sills or ramps at doorways or create a
trench which will contain any carried or dissolved solids and also
prevent accidental water contamination.
Use corrosion-resistant structural materials and lighting and ventilation systems in the storage area.
Containers made of nickel alloys are preferred. Steel containers are acceptable if temperatures are not elevated.
Storage tanks for solutions should be above ground and surrounded with dikes capable of holding entire contents.
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| SECTION 8. EXPOSURE CONTROLS/PERSONAL PROTECTION |
-
- NOTE:
Exposure to this material can be controlled in many ways. The measures
appropriate for a particular worksite depend on how this material is
used and on the extent of exposure. This general information can be
used to help develop specific control measures. Ensure that control
systems are properly designed and maintained. Comply with occupational,
environmental, fire, and other applicable regulations.
- Sampling and Analysis:
- Use
appropriate instrumentation and sampling strategy (location, timing,
duration, frequency, and number of samples). Interpretation of the
sampling results is related to these variables and the analytical
method. Sampling should be carried out by trained personnel.
- OSHA Analytical Methods:
- *NOTE:
The method described below has been reported for metal and metalloid
particulates and may also be suitable for sodium hydroxide solid. OSHA
Method ID-121 - OSHA Analytical Methods Manual, 2nd ed. (39). Metal and
Metalloid Particulates in Workplace Atmospheres (Atomic Absorption).
Validated method. Collection on mixed cellulose ester membrane filter.
Extraction with de-ionized water. Analysis by atomic absorption
spectrophotometry or by atomic emission spectrophotometry. Detection
limit: 0.009 ug/mL (analytical) and 0.0002 ug/mL (qualitative).
- NIOSH Analytical Methods:
- *NOTE:
The method described below has been reported for alkaline dusts
including sodium hydroxide solid. NIOSH METHOD 7401, Issue 2 - NIOSH
Manual of Analytical Methods. 4th ed. (40). Alkaline Dusts. Fully
evaluated method. Collection on PTFE membrane filter. Extraction with
0.01N hydrochloric acid. Analysis by acid-base titration with 0.01N
sodium hydroxide under nitrogen with endpoint by pH electrode.
Estimated LOD: 0.03 mg per sample (as sodium hydroxide).
- Colorimetric Detector Tubes:
- Not commercially available.
- Engineering Controls:
- Engineering
methods to control hazardous conditions are preferred. General methods
include mechanical ventilation (dilution and local exhaust), process or
personnel enclosure, control of process conditions and process
modification (e.g., substitution of a less hazardous material).
Administrative controls and personal protective equipment may also be
required.
Use a corrosion-resistant ventilation system separate
from other exhaust ventilation systems. Exhaust directly to the
outside. Use local exhaust ventilation, and process enclosure if
necessary, to control airborne dust and mist. Supply sufficient
replacement air to make up for air removed by exhaust systems.
- Personal Protective Equipment:
- If
engineering controls and work practices are not effective in
controlling exposure to this material, then wear suitable personal
protective equipment including approved respiratory protection. Have
appropriate equipment available for use in emergencies such as spills
or fire.
If respiratory protection is required, institute a
complete respiratory protection program including selection, fit
testing, training, maintenance and inspection. Refer to the CSA
Standard Z94.4-93, "Selection, Use, and Care, of Respirators,"
available from the Canadian Standards Association, Rexdale, Ontario,
M9W 1R3.
- Respiratory Protection Guidelines:
- NIOSH RECOMMENDATIONS FOR SODIUM HYDROXIDE CONCENTRATIONS IN AIR (3):
UP
TO 10 mg/m3: SAR operated in a continuous-flow mode; or full-facepiece
respirator with high-efficiency particulate filter(s); or powered air-
purifying respirator with dust and mist filter(s); or full-facepiece
SCBA; or full-facepiece SAR.
EMERGENCY OR PLANNED ENTRY INTO
UNKNOWN CONCENTRATIONS OR IDLH CONDITIONS: Positive pressure,
full-facepiece SAR; or positive pressure, full-facepiece SAR with an
auxiliary positive pressure SAR.
ESCAPE: Full-facepiece respirator with high-efficiency particulate filter(s); or escape-type SCBA.
NOTE: The IDLH concentration for sodium hydroxide is 10 mg/m3.
NOTE:
The purpose of establishing an IDLH value is to ensure that the worker
can escape from a given contaminated environment in the event of
failure of the most protective respiratory protection equipment. In the
event of failure of respiratory protective equipment every effort
should be made to exit immediately.
NOTE: Substance causes eye irritation or damage; eye protection needed.
Air-purifying respirators do not protect against oxygen-deficient atmospheres.
ABBREVIATIONS:
SAR = supplied-air respirator; SCBA = self-contained breathing
apparatus. IDLH = Immediately Dangerous to Life or Health.
The respirator use limitations specified by the approving agency and the manufacturer must be observed.
Recommendations apply only to NIOSH approved respirators.
- Eye/Face Protection:
- Chemical safety goggles. A face shield may also be necessary.
- Skin Protection:
- Chemical protective gloves, coveralls, boots and/or other resistant protective clothing.
Have a safety shower/eye-wash fountain readily available in the immediate work area.
- Resistance of Materials for Protective Clothing:
- Guidelines for sodium hydroxide, 30-70% (38):
RECOMMENDED (resistance to breakthrough longer than 8 hours): Butyl rubber, Natural rubber, Neoprene rubber,
Nitrile rubber, Polyethylene, Polyvinyl chloride, Viton(TM), Viton(TM)/Butyl rubber, Barrier (PE/PA/PE)
Silver Shield/4H(TM) (polyethylene/ethylene vinyl alcohol), Responder(TM), Trellchem(TM) HPS, Tychem(TM) BR/LV,
Tychem(TM) SL, Tychem(TM) TK.
NOT RECOMMENDED for use (resistance to breakthrough less than 1 hour): Polyvinyl alcohol.
Guidelines for sodium hydroxide, greater than 70% (38):
RECOMMENDED (resistance to breakthrough longer than 8 hours): Neoprene rubber, Polyvinyl chloride,
Trellchem(TM) HPS, Tychem(TM) BR/LV.
There is evidence that this material can cause serious skin injury (e.g. corrosion or absorption hazard).
Recommendations are NOT valid for very thin Natural rubber, Neoprene, Nitrile and PVC gloves (0.3 mm or less).
Resistance
of specific materials can vary from product to product. Breakthrough
times are obtained under conditions of continuous contact, generally at
room temperature. Evaluate resistance under conditions of use and
maintain clothing carefully.
- Personal Hygiene:
- Remove
contaminated clothing promptly. Keep contaminated clothing in closed
containers. Discard or launder before rewearing. Inform laundry
personnel of contaminant's hazards.
Do not eat, drink or smoke in work areas. Wash hands thoroughly after
handling this material. Maintain good housekeeping.
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THRESHOLD LIMIT VALUES (TLVs) / AMERICAN CONFERENCE OF GOVERNMENTAL INDUSTRIAL HYGIENISTS (ACGIH) / 2005
| Ceiling Exposure Limit (TLV-C): |
2 mg/m3 |
| TLV Basis - Critical Effect(s): |
Irritation |
- TLV Comments:
- NOTE:
In many jurisdictions, exposure limits are similar to the ACGIH TLVs.
Since the manner in which exposure limits are established, interpreted
and implemented can vary, obtain detailed information from the
appropriate government agency in each jurisdiction.
|
PERMISSIBLE EXPOSURE LIMITS (PELs) / FINAL RULE LIMITS / US OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION (OSHA)
| Ceiling Exposure Limit (PEL-C): |
2 mg/m3 |
-
- NOTE:
The OSHA PEL Final Rule Limits are currently non-enforceable due to a
court decision. The OSHA PEL Transitional Limits are now in force.
|
PERMISSIBLE EXPOSURE LIMITS (PELs) / TRANSITIONAL LIMITS / US OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION (OSHA)
| Time-Weighted Average (PEL-TWA): |
2 mg/m3 |
- Transitional Limit PEL Comments:
- These Permissible Exposure Limits are taken from 29 CFR 1910.1000 Table Z - 1.
|
EMERGENCY RESPONSE PLANNING GUIDELINES (ERPGs) / AMERICAN INDUSTRIAL HYGIENE ASSOCIATION (AIHA) / 2005
| ERPG-1: |
0.5 mg/m3 |
| ERPG-2: |
5 mg/m3 |
| ERPG-3: |
50 mg/m3 |
-
- The
ERPG-1 is the maximum airborne concentration below which it is believed
that nearly all individuals could be exposed for up to 1 hr without
experiencing other than mild transient adverse health effects or
perceiving a clearly defined, objectionable odor.
-
- The
ERPG-2 is the maximum airborne concentration below which it is believed
that nearly all individuals could be exposed for up to 1 hr without
experiencing or developing irreversible or other serious health effects
or symptoms which could impair an individual's ability to take
protective action.
-
- The
ERPG-3 is the maximum airborne concentration below which it is believed
that nearly all individuals could be exposed for up to 1 hr without
experiencing or developing life-threatening health effects.
-
- NOTE: Users of the ERPG values are strongly encouraged to consult the documentation before use.
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| SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES |
| SECTION 10. STABILITY AND REACTIVITY |
- Stability:
- Normally stable. Sodium hydroxide rapidly absorbs carbon dioxide from the air (forming sodium carbonate).(25)
- Hazardous Polymerization:
- Does not occur
- Incompatibility - Materials to Avoid:
-
NOTE: Chemical reactions that could result in a hazardous situation
(e.g. generation of flammable or toxic chemicals, fire or detonation)
are listed here. Many of these reactions can be done safely if
specific control measures (e.g. cooling of the reaction) are in
place. Although not intended to be complete, an overview of
important reactions involving common chemicals is provided to assist
in the development of safe work practices.
Sodium hydroxide reacts vigorously, violently or explosively with
many organic and inorganic chemicals, such as strong acids,
nitroaromatic, nitroparaffin and organohalogen compounds, glycols and
organic peroxides.
Reacts violently with water generating significant heat and dangerously spattering corrosive sodium hydroxide.
Violently polymerizes acetaldehyde, acrolein or acrylonitrile.
Produces flammable and explosive hydrogen gas if reacts with sodium tetrahydroborate or metals, such as aluminum, tin, or zinc.
Can form spontaneously flammable chemicals upon contact with 1,2- dichloroethylene, trichloroethylene or tetrachloroethane.
Can produce carbon monoxide upon contact with solutions of sugars, such as fructose, lactose and maltose.
References 21 and 36 provide more complete lists of chemicals that may react hazardously with sodium hydroxide.
- Hazardous Decomposition Products:
- None reported
- Conditions to Avoid:
- Water, moisture, air
- Corrosivity to Metals:
- Corrosive
to aluminum, tin, zinc, copper, brass and bronze. Corrosive to steel at
elevated temperatures (above 40 deg C). Not corrosive to nickel.(35,37)
|
| SECTION 11. TOXICOLOGICAL INFORMATION |
-
- Standard animal toxicity values are not available.
Toxicological
information for solutions has been included, since sodium hydroxide
purchased in solid form is commonly used in solution.
- Eye Irritation:
- Sodium
hydroxide has been extensively studied in animals because of its
ability to cause severe injury to the eyes. Factors which determine the
extent and reversibility of the injury include physical state (solid or
solution), concentration of solution, the amount of sodium hydroxide
which comes into contact with the tissue and the duration of contact.
Effects can range from mild irritation to severe corrosion with tissue
destruction, and may include blindness, permanent scarring and
death.(2,8,20) The following studies are typical of the research
available for sodium hydroxide.
- Application
of a 1% solution of sodium hydroxide produced necrosis covering about
3/4 of the cornea, or a more severe necrosis covering a smaller area (a
score of greater than 5.0 out of 10) in a standard Draize test with
rabbits.(24)
- Skin Irritation:
- Sodium
hydroxide has been extensively studied in animals because of its
ability to cause severe injury to the skin. Factors which determine the
extent and reversibility of the injury include physical state (solid or
solution), concentration of solution, the amount of sodium hydroxide
which comes into contact with the tissue and the duration of contact.
Effects can range from mild irritation to severe corrosion with tissue
destruction, and may include blindness, permanent scarring and
death.(2,8,20) The following studies are typical of the research
available for sodium hydroxide.
- Application
of 0.5 mL of 5, 10, 15 and 30% solutions of sodium hydroxide tested,
produced severe necrosis in 6/6 rabbits in 4 hours. The 15 and 30%
solutions produced severe ulcerative necrosis.(26) Application of 500
mg in a standard Draize test with rabbits produced severe damage to the
skin in 24 hours.(19)
- Effects of Short-Term (Acute) Exposure:
-
- Inhalation:
- In
one experiment, male rats were exposed to aerosols composed of sodium
hydroxide, sodium carbonate and their hydrated forms. Because sodium
hydroxide reacts rapidly with carbon dioxide in air to form sodium
carbonate which is less alkaline, the researchers maintained a high
concentration of sodium hydroxide by humidifying the air at 85%; later
they removed all carbon dioxide from the dilution air.(1) This
experiment is not considered relevant because of the combined exposure
and the extraordinary measures the researchers took to maintain the
sodium hydroxide aerosol. The researchers stated that the chemical
reaction between sodium hydroxide and carbon dioxide to form sodium
carbonate is so predominant, especially in the respiratory tract, the
toxicity of sodium carbonate may be the only factor worth considering".
Other historical studies on sodium hydroxide aerosol exposures have
also been criticized from this viewpoint.(4)
- Ingestion:
- Short-term
oral exposure in animals has produced severe corrosive damage to the
esophagus extending into surrounding tissues. In some cases, death has
resulted. In some cases, esophageal strictures have subsequently
developed in surviving animals.(27,28)
|
- Effects of Long-Term (Chronic) Exposure:
-
- Inhalation:
- Rats
were exposed to a finely dispersed aerosol of a 40% sodium hydroxide
solution twice weekly for 30 minutes for 2.5 months.(14) In a similar
study, 20 rats were exposed to an aerosol generated from a 5, 10, 20 or
40% sodium hydroxide solution, twice a week for 30 minutes for a month
before and a month after exposure to quartz dust for 3 days.(13) The
concentrations of sodium hydroxide aerosol achieved were not specified
for either study. In addition, neither study took into account the
reaction of sodium hydroxide with carbon dioxide in air and, in one
study the results are also confounded by the quartz exposure.
Therefore, no conclusions can be drawn.
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| SECTION 12. ECOLOGICAL INFORMATION |
-
- NOTE
: Inclusion of Ecological Information on an MSDS is optional under the
US Hazard Communication Standard and the Canadian Controlled Products
Regulations (WHMIS). In other jurisdictions, inclusion of Ecological
Information may be a requirement. For specific requirements, contact
the relevant regulatory authorities in the jurisdiction where the MSDS
is intended to be used.
The American National Standard for Hazardous Industrial
Chemicals - Material Safety Data Sheets - Preparation (ANSI
Z400.1-2004) provides advice on data that could be included in this
section.
Databases in CCOHS's CD-ROM and Web collection which contain useful Ecological Information include CESARS, HSDB® (Hazardous Substances Data Bank) and CHRIS (Chemical Hazards Response Information System).
|
| SECTION 13. DISPOSAL CONSIDERATIONS |
-
- Federal,
provincial and local regulations should be reviewed prior to disposal.
May be possible to neutralize, dilute and flush the material into a
sewer. May be possible to atomize dilute solutions in an approved
combustion chamber.
Harmful to aquatic life in high concentrations.
|
| SECTION 14. TRANSPORT INFORMATION |
| CANADIAN TRANSPORTATION OF DANGEROUS GOODS (TDG) SHIPPING INFORMATION |
-
| Shipping Name and Description: |
SODIUM HYDROXIDE, SOLID |
| UN Number: |
UN1823 |
| Class: |
8 |
 |
Packing Group/Risk Group: |
II |
|
Special Provisions: |
--- |
|
Passenger Carrying Road/Rail Limit: |
15 kg or L |
|
Marine Pollutant: |
--- |
-
- NOTE: This information incorporates the Transportation of Dangerous Goods Regulations SOR/2001-286, effective January 2, 2006.
|
| US DEPARTMENT OF TRANSPORT (DOT) HAZARDOUS MATERIALS SHIPPING INFORMATION (49 CFR) |
-
| Shipping Name and Description: |
SODIUM HYDROXIDE, SOLID |
| Hazard Class or Division: |
8 |
| Identification Number: |
UN1823 |
| Packing Group: |
II |
-
- NOTE:
This information was taken from the US Code of Federal Regulations
Title 49 - Transportation and is effective July 1, 2004.
|
|
| SECTION 15. REGULATORY INFORMATION |
| CANADIAN WORKPLACE HAZARDOUS MATERIALS INFORMATION SYSTEM (WHMIS) |
- CCOHS WHMIS Classification:
- E - Corrosive material
- WHMIS Health Effects Criteria Met by this Chemical:
- E - Corrosive to skin
E - TDG class 8 - corrosive substance
- WHMIS Ingredient Disclosure List:
- Included for disclosure at 1% or greater.
- Detailed WHMIS Classification According to Criteria:
- Class A - Compressed Gas:
- Does not meet criteria.
- Class B - Flammable and Combustible Material:
- Does not meet criteria.
Non- combustible (does not burn).
- Class C - Oxidizing Material:
- Does not meet criteria.
- Class D - Poisonous and Infectious Material. Division 1 - Immediate and Serious Toxic Effects:
- Insufficient information for classification.
- Acute Lethality:
- Insufficient information.
- Class D - Poisonous and Infectious Material. Division 2 - Other Toxic Effects:
- Does not meet criteria.
See detailed evaluation below.
- Chronic Health Effects:
- Insufficient information.
- Carcinogenicity:
- Does not meet criteria. Not included in standard reference lists.
- Teratogenicity and Embryotoxicity:
- Insufficient information.
- Reproductive Toxicity:
- Insufficient information.
- Mutagenicity:
- Insufficient information.
No in vivo studies reported.
- Respiratory Tract Sensitization:
- Does not meet criteria.
Not reported as human respiratory sensitizer.
- Skin Irritation:
- Corrosive materials are not also classified as irritants.
- Eye Irritation:
- Corrosive materials are not also classified as irritants.
- Skin Sensitization:
- Insufficient information.
- Class E - Corrosive Material:
- Meets criteria.
Corrosive to animal skin and aluminum; TDG Class 8
- Class F - Dangerously Reactive Material:
- Does not meet criteria.
|
| US OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION (OSHA) HAZARD COMMUNICATION STANDARD (29 CFR 1910.1200) |
- OSHA Hazard Communication Evaluation:
- Meets criteria for hazardous material, as defined by 29 CFR 1910.1200.
|
| EUROPEAN UNION (EU) CLASSIFICATION AND LABELLING INFORMATION |
- EU Classification:
- Corrosive. Causes severe burns. [C] (23)
- EU Risk Phrases:
- Causes severe burns [R35]
- EU Safety Phrases:
- Keep
locked up and out of reach of children.* In case of contact with eyes,
rinse immediately with plenty of water and seek medical advice. Wear
suitable gloves. Wear eye/face protection. In case of accident or if
you feel unwell, seek medical advice immediately (show label where
possible). [S:(1/2-)*26-37/39-45].
*This safety phrase can be omitted from the label when the substance or preparation is sold for industrial use only.
- EU Comments:
- CONCENTRATIONS LIMITS:
CONCENTRATION GREATER THAN OR EQUAL TO 5%: Corrosive. Causes severe burns. [C.; R35].
CONCENTRATION LESS THAN 5% AND GREATER THAN OR EQUAL TO 2%: Corrosive. Causes burns. [C; R34].
CONCENTRATION LESS THAN 2% AND GREATER THAN OR EQUAL TO 0.5%: Irritant. Irritant to eyes and skin. [Xi; R36/38].
Safety phrases relate to the highest concentration division indicated, but may also be applicable to lower concentrations.
|
|
| SECTION 16. OTHER INFORMATION |
- Selected Bibliography:
- (1)
Zwicker, G.M., et al. Toxicity of aerosols of sodium reaction products.
Journal of Environmental Pathology and Toxicology. Vol. 2 (1979). p.
1139-50
(2) National Institute for Occupational Safety and Health.
Criteria for a recommended standard: occupational exposure to sodium
hydroxide. Department of Health, Education and Welfare, 1975
(3) NIOSH pocket guide to chemical hazards. National Institute for Occupational Safety and Health, June 1994. p. 284-285
(4)
Cooper, D.W., et al. A critique of the US standard for industrial
exposure to sodium hydroxide aerosols. American Industrial Hygiene
Association Journal. Vol. 40, no. 5 (1979). p. 365-371
(5) Malten, K.E., et al. Injury to the skin by alkali and its regeneration. Dermatologica. Vol. 132 (1966). p. 124-130
(6)
Nagao, S., et al. The effect of sodium hydroxide and hydrochloric acid
on human epidermis: an electronmicroscopic study. Acta Dermatovener
(Stockholm). Vol. 52 (1972). p. 11-23
(7) Morris, G.E. Chemical
alopecia: a unique case. Archives of Industrial Hygiene and
Occupational Medicine. Vol. 6 (1952). p. 530-531
(8) Grant, W.M. Toxicology of the eye. 4th edition. Charles C. Thomas, 1993. p. 82-86, 1302-1310
(9)
Hughes, W.F. Jr. Alkali burns of the eye. I. Review of the literature
and summary of present knowledge. Archives of Ophthalmology. Vol. 92
(1946). p. 423-449
(10) Dennis, R.H. A simple procedure for
treatment of alkali burns of the eye. The Journal of the Maine Medical
Association. Vol. 45 (1954). p. 332-34
(11) Girard, L.J., et al.
Severe alkali burns. Transactions of the American Academy of
Ophthalmology & Otolaryngology. Vol. 74 (July-August, 1970). p.
788-803
(12) Ott, M.G., et al. Mortality among employees chronically
exposed to caustic dust. Journal of Occupational Medicine. Vol. 19, no.
12 (December, 1977). p. 813-861
(13) Vyskocil, J., et al. The effect
of aerosol inhalations of sodium hydroxide on the elimination of quartz
dust from lungs of rats: experimental studies of dust elimination from
the lungs: IVth communication. Scripta Medica. Vol. 39, no. 1 (1966).
p. 25-29
(14) Dluhos, M., et al. Experimental study of the effect of
aerosol inhalations of sodium hydroxide on the respiratory tract of
rats. Vnitrni Lekarstvi. Vol. 15, no. 1 (1969). p. 38-42 (English
translation: NIOSHTIC Control Number: 00048773).
(15) Benedict, E.B.
Carcinoma of the esophagus developing in benign stricture. New England
Journal of Medicine. Vol. 224, no. 10 (March 6, 1941). p. 408-412
(16)
Bigelow, N.H. Carcinoma of the esophagus developing at the site of lye
stricture. Cancer. Vol. 6 (November, 1953). p. 1159-1164
(17)
Kiviranta, U.K. Corrosion carcinoma of the esophagus: 381 cases of
corrosion and nine cases of corrosion carcinoma. Acta Otolaryngologica.
Vol. 42 (1952). p. 89-95
(18) Nash, P.E., et al. Pneumothorax
following inhalation of caustic soda fumes. Archives of Emergency
Medicine. Vol. 5, no. 1 (1988). p. 45-47
(19) RTECS record for sodium hydroxide. Date of last update: 9504
(20)
Pierce, J.O. Alkaline Materials. In: Patty s Industrial Hygiene and
Toxicology. 4th edition. Volume II. Toxicology. Part A. John Wiley
& Sons, Inc., 1993. p. 771-773, 779-781
(21) Fire protection
guide to hazardous materials. 13th ed. Edited by A.B. Spencer, et al.
National Fire Protection Association, 2002. NFPA 49; NFPA 491
(23) European Economic Community. Commission Directive 93/72/EEC. September 1, 1993
(24)
Carpenter, C.P., et al. Chemical burns of the rabbit cornea. American
Journal of Ophthalmology. Vol. 29 (1946). p. 1363-1372
(25) HSDB record for sodium hydroxide. Last revision date: 95-01-24.
(26)
Harton, E., et al. Toxicological and skin corrosion testing of selected
hazardous materials. Final Report 1973-1974. Report No.
DOT/MTB/OHMO-76/2. Office of Hazardous Materials Operations, U.S.
Department of Transportation, April, 1976. (National Technical
Information Service Report No. PB-264 975).
(27) Bosher, L.H., et
al. The pathology of experimentally produced lye burns and strictures
of the esophagus. The Journal of Thoracic and Cardiovascular Surgery.
Vol. 21 (1951). p. 483-489
(28) Krey, H. On the treatment of
corrosive lesions in the oesophagus: an experimental study. Acta
Oto-Laryngologica. Supplementum 102 (1952).
(29) Morita, T., et al.
Effects of pH in the in vitro chromosomal aberration test. Mutation
Research. Vol. 225 (1989). p. 55-60
(30) Demerec, M., et al. A
survey of chemicals for mutagenic action on E. Coli. The American
Naturalist. Vol. 85, no. 821 (March-April, 1951). p. 119-136
(31)
Martin, F.M. Summary review of the health effects associated with
sodium hydroxide: health issue assessment. Report No. EPA/600/8-88/081.
Office of Health and Environmental Assessment, U.S. Environmental
Protection Agency, June, 1988. (National Technical Information Service
Report No. PB88-231949).
(32) Rubin, A.E., et al. Obstructive airway
disease associated with occupational sodium hydroxide inhalation.
British Journal of Industrial Medicine. Vol. 49 (1992). p. 213-214
(33)
Hansen, K.S., et al. Obstructive lung injury after treating wood with
sodium hydroxide. Journal of the Society of Occupational Medicine. Vol.
41, no. 1 (1991). p. 45-46
(34) Bond, G.G., et al. A case-control
study of renal cancer mortality at a Texas chemical plant. American
Journal of Industrial Medicine. Vol. 7 (1985). p. 123-139
(35)
Curlin L.C., et al. Alkali and chlorine products. In: Kirk-Othmer
encyclopedia of chemical technology. 4th Edition. Volume 1. John Wiley
and Sons, 1991. p. 1004-1025
(36) Bretherick, L. Bretherick's
handbook of reactive chemical hazards. 4th edition. Butterworths, 1990.
p. 11-12, 31, 121, 133, 223, 247-248, 418- 419, 603-604, 1182-1184,
1472, 1474, 1489, 1695-1696
(37) Corrosion data survey: metals section. 6th edition. National Association of Corrosion Engineers, 1985. p. 118-119
(38) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002
(39)
Occupational Safety and Health Administration (OSHA). Metal and
Metalloid Particulates in Workplace Atmospheres (Atomic Absorption).
In: OSHA Analytical Methods Manual. Revision Date: Oct. 31, 2001.
Available at: <www.osha-slc.gov/dts/sltc/methods/toc.html>
(40)
National Institute for Occupational Safety and Health (NIOSH). Alkaline
Dusts. In: NIOSH Manual of Analytical Methods (NMAM(R)). 4th ed. Edited
by M.E. Cassinelli, et al. DHHS (NIOSH) Publication 94-113. Aug. 1994.
Available at: <www.cdc.gov/niosh/nmam/nmammenu.html>
-
- Information
on chemicals reviewed in the CHEMINFO database is drawn from a number
of publicly available sources. A list of general references used to
compile CHEMINFO records is available in the database Help.
| Review/Preparation Date: 1995-11-29 |
- Revision Indicators:
-
| Sampling |
1996-06-01 |
| Respiratory guidelines |
1996-06-01 |
| Resistance of materials |
1996-06-01 |
| US transport |
1998-03-01 |
| Resistance of materials |
1998-06-01 |
| Bibliography |
1998-06-01 |
| ERPG |
2001-03-01 |
| TDG |
2002-05-29 |
| Bibliography |
2003-04-15 |
| PEL transitional comments |
2003-11-18 |
| Resistance of materials for PPE |
2004-03-31 |
| Bibliography |
2005-03-20 |
| Sampling/analysis |
2005-03-20 |
|
|
|
 |
©2006 Canadian Centre for Occupational Health & Safety 
