|
DISSOLVED ACETYLENE
Source: Canadian Centre for Occupational Health and Safety
CHEMINFO
*** SECTION1. CHEMICAL IDENTIFICATION ***
CHEMINFO RECORD NUMBER : 49
CCOHS CHEMICAL NAME :Acetylene
SYNONYMS :
*ETHYNE
*ETHINE
*NARCYLEN
*ACETYLENE
GAS REGISTRY NUMBER : 74-86-2
PIN (UN/NA NUMBER(S) : 1001
RTECS NUMBER(S) :AO9600000
CHEMICAL FAMILY : Unsaturated aliphatic hydrocarbon /
alkyne
MOLECULAR FORMULA : C2-H2
STRUCTURAL FORMULA : H-C#C-H (# denotes a triple bond)
*** SECTION 2. DESCRIPTION ***
APPEARANCE AND ODOUR:
Pure acetylene is a colorless, odourless gas. Technical and
commercial grades have a garlic odour due to the presence of
impurities(5)
ODOUR THRESHOLD:
240 MG/M3 (226 PPM) (DETECTION) (4); 657 MG/M3 (620 PPM) (NOT
SPECIFIED) (8)1300-2750 MG/M3 (1222-2585 PPM) (NOT SPECIFIED)
(4)
WARNING PROPERTIES:
NOT RELIABLE - odour threshold about the same magnitude as the
NIOSH recommended exposure limit.
COMPOSITION/PURITY:
Crude acetylene and some commercial grades contain traces of
ammonia,arsine,hydrogen sulfide, and phosphine. A number of case
reports of injury or death following acetylene exposure have been
attributed to the presence of toxic impurities such as
phosphine.(1) (See CHEMINFO record 716E for information on
phosphine) Acetylene is normally shipped in cylinders under
pressure as a solution in acetone with a porous filler. (See
CHEMINFO record 30E for information on acetone).
USES AND OCCURRENCES:
Primarily used as a raw material in the production of chemicals
such as acetaldehyde, acetic acid, acrylonitrile, perchloroethy
lene, vinyl chloride,and trichloroethylene. Also used for oxyace
tylene welding, cutting and heat-treating. Small amounts used
for lighting purposes in buoys and beacons, and as a fuel in
atomic absorption instruments.
:2:
*** SECTION 3. HAZARDS IDENTIFICATION ***
** EMERGENCY OVERVIEW **
Colourless gas with no or slight garlic-like odour depending on
purity.FLAMMABLE GAS. Can be ignited by static discharge or
friction. May decompose with explosive violence at elevated
temperature[ and pressures.
COMPRESSED GAS. Forms very sensitive explosive metallic salts.
Simple asphyxiant. May reduce oxygen available for breathing.
High concentrations may accumulate in confined spaces.
** POTENTIAL HEALTH EFFECTS **
EFFECTS OF SHORT-TERM (ACUTE) EXPOSURE:
INHALATION:
At concentrations below the lower explosive limit (LEL) OF 2.5%
(25000 ppm),acetylene is essentially non-toxic.(1.3) At higher
concentration, it has anesthetic action and at even higher levels
is a simple asphyxiant. Its narcotic action is about 1.5 times
that of ethylene.(3) The main health concern of acetylene is that
it can displace oxygen in the atmosphere and cause suffocation
due to lack of oxygen (asphyxiation). In one case, a person
working in a process generating acetylene became unconscious
rapidly and died after he put his head inside a calcium carbide
feed hopper where it is believed there was an oxygen deficiency
and a high (up to 80%) acetylene concentration.(9) For every5%
(50000 ppm) increase in acetylene in the atmosphere, there is
about a 1% decrease in oxygen content. Normal atmospheric cont
ent of oxygen is 21.5%. Oxygen content in the atmosphere must
not fall below 18% or effects of oxygen deficiency will occur. It
is unlikely that enough acetylene will escape and accumulate in
an open workplace to significantly displace oxygen in the at
mosphere. However, in a confined space, it is possible for high
concentrations of acetylene to accumulate. In such an event,a
significant amount of oxygen may be displaced. Effects of oxygen
deficiency are as follows: 12-16% oxygen content can cause the
breathing and pulse rate to increase and muscular coordination
can be slightly disturbed; 10-14% oxygen content can cause emo
tional upset, abnormal fatigue and disturbed respiration; 6-10%
oxygen content can cause nausea, vomiting, collapse or loss of
consciousness; oxygen content below 6% can cause convulsive
movements, possible respiratory collapse and death.(12) Acetylene
produces varying degrees of temporary narcosis when administered
with oxygen at concentrations of 100,000 ppm(10%) or greater.In
an experiment, in which volunteers were exposed to high concen
trations of acetylene in an atmosphere where oxygen content was
artificially maintained, central nervous system(CNS) effects were
observed.(6) phosphine and arsine, two very toxic gases, are
sometimes present in acetylene at low concentrations. There are
case reports of injury and death attributed to the impurities in
acetylene.(9) For more information on phosphine, see CHEMINFO
record 716E.
SKIN CONTACT:
Gas is not irritating. Some sources report that the liquid could
cause frostbite. However, this is not possible because acety
lene cylinders contain acetylene gas dissolved in acetone. Any
skin contact liquid would be with acetone since the acetylene
would be rapidly released. Acetone is a slight skin irritant.
EYE CONTACT:
Gas is not irritating. Some sources report that the liquid could
cause frostbite. However, this is not possible because acetylene
cylinders contain acetylene gas dissolved in acetone. Any eve
contact with liquid would be with small amounts of acetone,since
the acetylene would be rapidly released. Acetone is a moderate
eye irritant.
INGESTION:
Not applicable. Acetylene is a gas.
EFFECTS OF LONG-TERMS(CHRONIC) EXPOSURE:
None reported
CARCINOGENICITY:
No information available
TERATOGENICITY AND EMBRYOTOXICITY:
No information available
REPRODUCTIVE TOXICITY:
No information available
ITAGENICITY:
No information available
TOXICOLOGICALLY SYNERGISTIC MATERIALS:
No information available
POTENTIAL FOR ACCUMULATION:
Does not accumulate
*** SECTION 4. FIRST AID MEASURES ***
INHALATION:
This product is flammable. Take proper precautions (e.g remove
any sources of ignition). Also, take proper precautions to ensure
your own safety before attempting rescue, (e.g. wear appropriate
protective equipment, use the "buddy" system). Remove source of
contamination or move victim to fresh air. If breathing has
stopped, properly trained personnel should begin artificial
respiration or cardiopulmonary resuscitation(CPR) immediately.
Oxygen may be beneficial if administered by a person trained in
its use,preferably on a doctor's advice. Obtain medical atten
tion immediately.
SKIN CONTACT:
Not applicable for gas. If skin contact occurs with liquid from
cylinders of acetylene dissolved in acetone, immediately flush
with lukewarm, gently flowing water for at least 5 minutes, or
until the chemical is removed. Remove contaminated clothing,
shoes and leather goods (e.g. watchbands,belts). If irritation
persists.repeat flushing. Obtain medical advice immediately.
Completely decontaminate clothing,shoes and leather goods before
reuse or discard.
EYE CONTACT:
Not applicable for gas. If eye contact occurs with liquid from
cylinders of acetylene dissolved in acetone, immediately flush
the contaminated eye(s) with lukewarm,gently flowing water for 10
minutes, or until the chemical is removed, while holding the
eyelids open. Obtain medical advice immediately.
INGESTION:
Not applicable to gas.
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 if inhalation or skin 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 obtained, as
required. All first aid procedures should be periodically re
viewed by a doctor familiar with he material and its condition of
use in the workplace.
*** SECTION 5. FIRE FIGHTING MEASURES ***
FLASH POINT:
Flammable gas
LOWER FLAMMABLE (EXPLOSIVE) LIMIT (LFL/LEL):
2.5% (7)
UPPER FLAMMABLE (EXPLOSIVE)LIMIT (UFL/UEL)
81% (2); 100% if there is a substantial energy ignition source,
and under certain conditions of pressure, container size and
shape.(5)
AUTO IGNITION(IGNITION) TEMPERATURE:
305 deg C (581 deg F) (7); 406-440 deg C (763-824 deg F ) (2)
EXPLOSION DATA - SENSITIVITY TO MECHANICAL IMPACT:
Information not available
EXPLOSION DATA - SENSITIVITY TO STATIC CHARGE:
Acetylene gas is extremely flammable and can be readily ignited
by static discharge if concentration exceeds lower explosive
limit.
COMBUSTION AND THERMAL DECOMPOSITION PRODUCTS:
Carbon monoxide (CO), carbon dioxide (CO2)
FIRE HAZARD COMMENTS:
Flammable gas. Can readily form explosive mixtures with air over
a very wide range. Explosion hazard in confined spaces. Pure
acetylene can explode under certain conditions of elevated pres
sure and temperature and container size.(5) Reacts with active
metals to form explosive acetylene compounds.
EXTINGUISHING MEDIA:
Dry chemical, carbon dioxide, water spray, fog, foam.
FIRE FIGHTING INSTRUCTIONS:
Move containers from fire area if it can be done without risk.
For fires involving flammable gases, the best procedure is to
stop the flow of gas before attempting to extinguish the fire.
The gas could form explosive mixture and reignite. If this
cannot be done, let fire burn. Isolate materials not yet in
volved in the fire and protect personnel. Keep cooling streams
of water on fire-exposed tanks or containers. Caution must be
used in approaching the fire and applying water. Containers may
explode violently in fire. Stay away from ends of tanks. Fight
fires from a location protected from the effects of an explosion.
For massive fire in large area, use unmanned hose holder or
monitor nozzles; if this is not possible, withdraw from area and
allow fire to burn. Withdraw immediately in case of rising sound
from venting safety device or any discolouration of tank due to
fire. Acetylene, itself, is only slightly hazardous to health.
However, it can displace oxygen, in the air,reducing the amount
available for breathing. As in any fire, wear self-contained
breathing apparatus(SCBA),
pressure-demand,(MSHA/NIOSH approved or equivalent) and full
protective equipment (Bunker Gear).
** NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)
HAZARD INDEX **
NFPA - HEALTH :1 - Exposure would cause irrita
tion but only minor residual
injury.
NFPA - FLAMMABILITY : 4 - Will rapidly or completely
vaporize,or readily disperse
in air and burn.
NFPA - REACTIVITY : 3 - Capable of detonation or
explosive decomposition or
reaction but requires a strong
initiating source, or must be
preheated under confinement, or
reacts explosively with water.
*** SECTION 6. ACCIDENTAL RELEASE MEASURES
PRECAUTIONS :
Restrict access to area until completion of cleanup. Ensure
cleanup is conducted by trained personnel only. Provide adequate
personal protective equipment. Ventilate area. Eliminate all
ignition sources. NEVER test for a leak with an open flame.
CLEAN-UP :
Stop leak if you can do it without risk. If leak cannot be
stopped, move the cylinder to an open space away from all sources
of ignition. Open the valve slightly and allow acetylene to
escape slowly. Place a sign warning persons not to approach the
area with cigarettes or other sources of ignition. Isolate area
until gas has dispersed.
*** SECTION 7. HANDLING AND STORAGE ***
HANDLING :
Use in minimal quantities in a well-ventilated area separate
from the storage area. practice good housekeeping and good per
sonal hygiene. Maintain handling equipment. Have suitable
emergency equipment for fires,spills and leaks readily available.
Document and practice your emergency plan. Do not use with
incompatible materials, such as soft metals (e.g. brass), halons
(e.g. chlorine), oxidizers (e.g. nitric acid). Use standard
precautions if gas is used for welding. Leave cylinder cap in
place until cylinder is secured and ready for use. Always chain
or otherwise securely restrain cylinders in an upright position
to a wall, rack or other solid structure when they are being
used. Do not open cylinder if damaged. Never use excessive
force when opening. Use the appropriate pressure regulator.
Ensure equipment is compatible with cylinder pressure and cont
ents. Follow supplier recommendations. Open cylinder valve
slowly to prevent rapid compression and damage to valve seat.
Shut flow off at cylinder valve and not at regulator when not in
use. Avoid damaging cylinders. Use a hand cart or other mechan
ical moving device to transport cylinders. Do not roll, drop or
strike cylinders together. Do not lift cylinders by the cap or a
lifting magnet. Keep empty cylinders under slightly positive
pressure. Follow supplier/manufacturer recommendations on han
dling this material. Avoid all ignition sources. Post "no-
smoking" signs in area of use. Keep all areas where this materi
al is handled or used clear of materials which can burn. Use non-
sparking ventilation systems, approved explosion-proof equipment
and intrinsically safe electrical systems in areas of use. Use
spark-resistant tools. Ground all cylinders and storage vessels.
STORAGE:
Storage area should be clearly identified, well-illuminated,
clear of obstruction and accessible only to trained and author
ized personnel. Inspect all incoming containers before storing to
ensure they are undamaged and properly labeled. Store in a cool,
dry, well-ventilated area out of direct sunlight. Store away
from incompatible materials, such as halogens (e.g. chlorine),
oxidizers (e.g.nitric acid). Follow any special instructions for
storage on supplier/manufacturer Material Safety Data sheet
(e.g.maximum storage quantities and temperature requirements).
Consider leak detection and alarm equipment for storage area.
Store compressed gas cylinders in compliance with occupational
health and safety regulations and fire and building codes apply
ing to your workplace. Avoid storage of cylinders for more than
six months. Protect cylinders from corrosion by keeping surface
of storage area dry. Always check cylinder valve for evidence of
damage, rust or dirt which may inhibit operation before storage
and use. Check that the cylinder was last tested within the
required time. Store cylinders sway from flammable materials and
in a fire resistant area away from process and handling areas.
Always chain or otherwise securely restrain cylinders in an
upright position to a wall, rack or other solid structure when
they are stored. Check compatibility with other materials in
cluding other compressed gases and separate at the appropriate
distance. Store empty cylinders separate from full ones with
valves shut off,cap secure and labeled EMPTY or "MT".Follow
supplier/manufacturer recommendations on storage, quantity,tem
perature and other storage conditions.
Store away from all heat and ignition sources. Use non-sparking
ventilation systems, approved explosion-proof equipment and
intrinsically safe electrical systems. Keep quantity stored as
small as possible. Store away from process and production areas,
away from elevators, building and room exits or main aisles
leading to exits. Keep storage area clear of materials which can
burn. Have appropriate extinguishing capability in storage area
(e.g. sprinkler system, portable fire extinguishers). Ground all
cylinders and storage vessels.
***SECTION 8. EXPOSURE CONTROLS/PERSONAL PROTECTION ***
NOTE: Exposure to this material can be controlled in many ways.
The measures appropriate for a particular work site depend on how
this material is used and on the extent of exposure. This gener
al information an be used to help develop specific control meas
ures. 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). Interpreta
tion of the sampling results is related to these variables and
the analytical method. Sampling should be performed by trained
personnel.
CALORIMETRIC-INDICATING (DETECTOR) TUBES: Commercially available.
OSHA METHOD: IMIS0070 (not validated for acetylene).
DIRECT READING INSTRUMENTS: Commercially available devices in
clude: heat of combustion detector, infrared photometer, gas
chromatograph analyzer.
NOTE: Measure oxygen content in the workplace air when ever high
concentrations of acetylene could displace oxygen or create a
risk of fire.
ENGINEERING CONTROLS:
Engineering methods to control hazardous conditions are pre
ferred. Methods include mechanical ventilation (dilution and
local exhaust), process or personnel enclosure, control of pro
cess conditions, and process modification (e.g.substitution of a
less hazardous material). Administrative controls and personal
protective equipment may also be required. Acetylene gas is
unstable at high pressures. Generation, distribution through
hose or piping, or utilization of acetylene should be maintained
at a pressure less than 15 psi gauge (100 kpa gage).(7) For pres
sures greater than 15 psi gage specialized equipment is required.
Protect against lighting and static electricity.(7) Steel and
wrought iron are recommended for use with acetylene. Rolled,
forged, or cast steel, or malleable iron fittings may be used.
The use of cast iron fittings is not recommended. Unalloyed
copper,silver,mercury, 70-30 brass and aluminum-bronze should not
come in contact with acetylene due to the possible formation of
explosive acetylides.(2,5)provided sufficient local exhaust and
general (dilution) ventilation to maintain levels of airborne
acetylene below one tenth the lower explosive limit (one tenth of
the LEL of acetylene is 2500 ppm). Use a non-sparking grounded
ventilation system separate from other exhaust ventilation sys
tems. Exhaust directly to the outside, taking necessary precau
tions for environmental protection. Supply sufficient replacement
directly to make up for air removed by exhaust system. Where
conditions of use are such that phosphine or other impurities may
present a hazard to health, the composition of the acetylene
should be determined from the supplier or by analysis.
PERSONAL PROTECTIVE EQUIPMENT:
Respiratory protective equipment is not ordinarily required when
handling small quantities of acetylene. In areas of potential
oxygen deficiency or where equipment failure may cause an imme
diate high concentration of this material, approved respiratory
protective equipment should be readily available. If respiratory
protection is required, institute a complete respiratory protec
tion program including selection, fit testing, training, main
tenance, inspection, cleaning and evaluation. Refer to the CSA
Standard Z94.4-M1982,"Selection, Care, and Use of Respirators".
available from the Canadian Standards Association, Rex dale,On
tario, M9W 1R3.
RESPIRATORY PROTECTION GUIDELINES:
EMERGENCY OR PLANNED ENTRY INTO UNKNOWN CONCENTRATIONS OR INTO AN
AREA WHERE THERE IS LESS THAN 18% OXYGEN: Positive Pressure,
full-face piece self-contained breathing apparatus or positive
pressure, full-face piece supplied-air respirator with an auxili
ary positive pressure self-contained breathing apparatus.
ESCAPE: Escape-type self-contained breathing apparatus.
EYE-FACE PROTECTION:
No specific requirement, but it is good practice to wear chemi
cal safety goggles.
SKIN PROTECTION:
No specific requirement during normal use. However, fire-
resistant clothing is recommended in work areas where a signifi
cant release of flammable gas is possible (e.g.during some main
tenance activities) or during an emergency entry into a flammable
atmosphere.
RESISTANCE OF MATERIALS FOR PROTECTIVE CLOTHING:
Not applicable
EXPOSURE CONTROLS/PERSONAL PROTECTION COMMENTS:
Do not smoke in work area.
**EXPOSURE GUIDELINES **
*THRESHOLD LIMIT VALUES (TLVs)/COMMERCIAL CONFERENCE OF
GOVERNMENTAL INDUSTRIAL HYGIENISTS (ACGIH)/1992-93*
TIME-WEIGHTED AVERAGE (TLV-TWA) : Simple asphyxiant
TLV COMMENTS:
SIMPLE ASPHYXIANT: Primary health concern is displacement of
oxygen is air. Ensure that oxygen content remains above 18% by
volume. Keep gas concentration safely below lower explosive
limit. It is a good practice to maintain the concentration of a
flammable gas below one tenth of the lower explosive limit (LEL).
For acetylene, one tenth of the LEL is 2500 ppm(2663 mg/m3).
NOTE: In many Canadian jurisdictions, exposure limits are similar
to the ACGIH TLVs. Since the manner in which exposure limits are
established, interpreted, and implemented can vary, obtain de
tailed information from the appropriate government agency in each
jurisdiction.
*PERMISSIBLE EXPOSURE LIMITS (PELs)/
FINAL RULE LIMITS/ OCCUPATIONAL
SAFETY AND HEALTH ADMINISTRATION (OSHA) *
TIME WEIGHTED AVERAGE (PEL-TWA) : Not established
NOTE: The OSHA PEL Final Rule Limits are currently
non-enforceable due to a court decision. The OSHA PEL Transi
tional Limits are now in force.
*PERMISSIBLE EXPOSURE LIMITS (PELs)
TRANSITIONAL LIMITS/ OCCUPATIONAL
SAFETY AND HEALTH ADMINISTRATION (OSHA) *
time weighted average 9PEL-TWA) : Not established
*** SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES ***
MOLECULAR WEIGHT : 26.04
CONVERSION FACTOR:
1ppm = 1.065 mg/m3; 1 mg/m3 = 0.94 ppm at 25 deg C
MELTING POINT :-81 deg C(-113 deg F)
(triple point)
BOILING POINT :-84 DEG c (-119 deg F)
(sublimation point)
RELATIVE DENSITY (SPECIFIC GRAVITY)
Not applicable
SOLUBILITY IN WATER:
1.7 vol/vol at0 deg C (32 deg F ) and 1 atmosphere (101.kpa).(5)
SOLUBILITY IN OTHER LIQUIDS:
Soluble;e in many organic solvents (e.g.) acetone,benzene, etha
nol)slightly soluble in carbon disulphide.
VAPOUR DENSITY : 0.908 (AIR = 1) (2,5)
VAPOUR PRESSURE : 4479 kpa(44.2 ATM) AT 21.1 DEG c
(2); 4378 kpa (43.2 atm (5)
SATURATION VAPOUR CONCENTRATION: Not applicable
EVAPORATION RATE : Not applicable
PH VALUE : Not applicable
CRITICAL TEMPERATURE : 35.2 DEG c(95.36 DEG f(2); 36.0
DEG C (97 DEG F) (5)
COEFFICIENT OF OIL/WATER DISTRIBUTION (PARTITION COEFFICIENT):
Not available
OTHER PHYSICAL PROPERTIES:
CRITICAL PRESSURE: 6190 kpa (61.1 atm (2); 6250 kpa 61.7 atm (5)
*** SECTION 10 STABILITY AND REACTIVITY
STABILITY:
Stable at standard temperature and pressure. Gaseous acetylene
may decompose explosively to hydrogen and carbon at elevated
temperatures and pressures. The higher the pressure, the easier
it is for an explosion to occur. Pressures below 15 psi gage (100
kpa gage) are regarded as safe. (5,7)
HAZARDOUS POLYMERIZATION:
Can occur when heated or compressed
CONDITIONS TO AVOID:
statics DISCHARGE, FRICTION.HAZARDOUS DECOMPOSITION PRODUCTS:
hydrogen
INCOMPATIBILITY - MATERIALS TO AVOID:
Brass - in the presence of wet acetylene and ammonia, brass with
more than 60% copper can react readily to produce explosive
acetylides.(7) CALCIUM HYPOCHLORITE - can react to produce
explosive chloroacetylenes.(10) COPPER MERCURY AND SILVER SALTS -
produce acetylene from ammonia Cal solutions. The dried ace
tylides are extremely sensitive and can explode
violently.(7)HALOGENS (e.g. bromine,chlorine, iodine,fluorine) -
can react explosively.(7,10) HEAVY METALS
(E.G.COPPER,MERCURY,SILVER): REACT to produce explosive ace
tylides.(7,10) HYDRIDED (E.G) sodium hydride, cesium hydride,
rubidium hydride)- reach vigorously if moisture is present.(7)
LIQUID NITROGEN - can react explosively.(10) NITRIC ACID - con
tact with acetylene in the presence of mercury salts can produce
explosive trinitromethane.(10) OXYGEN- produces explosive mix
tures (10) OZONE reacts explosively (10) PERCHLORIC ACID - explo
sions have occurred in atomic absorption spectrometers using
acetylene-nitrous oxide flames when sample solutions containing
perchloric acid were used.(10) POTASSIUM- molten potassium ig
nites, then explodes in acetylene.(10)
CORROSIVITY TO METALS:
Not corrosive
*** SECTION 11. TOXICOLOGICAL INFORMATION ***
EFFECTS OF SHORT-TERM INHALATION EXPOSURE: Animals have shown
tolerance at 10 per cent acetylene. In studies with dogs, cats
and rabbits,acetylene acts as an anesthetic (causes drowsiness
and unconsciousness) at concentrations about 20 per cent (200,000
ppm). Recovery may occur if oxygen content of atmosphere is
maintained. In an oxygen-deficient atmosphere (50 per cent acety
lene) in air, death may occur after 5-10 minutes.(1)
Rodents exposed to 25, 50 and 80 percent acetylene in oxygen for
1-2 hours daily up to 93 hours, showed no organ weight changes or
cellular injuries. 80% acetylene/20% oxygen mixture caused a rise
in blood pressure in the cat.(3)
*** SECTION 12. ECOLOGICAL INFORMATION ***
Not: This section is under development.
***SECTION 13. DISPOSAL CONSIDERATIONS ***
Allow gas to dissipate safely into the atmosphere or use as fuel.
*** SECTION 14. TRANSPORT INFORMATION ***
** TRANSPORTATION OR DANGEROUS GOODS (TDG) SHIPPING INFORMATION
SHIPPING NAME AND DESCRIPTION: Acetylene, liquefied
PRODUCT IDENTIFICATION NUMBER (PIN): --
CLASSIFICATION: --
SPECIAL PROVISIONS: 47:NO person shall handle, offer for trans
port or transport this article, product or substance.'
IMO CLASSIFICATION: --
ICAO CLASSIFICATION: ---
PACKING GROUP: ---
SHIPPING NAME AND DESCRIPTION: Acetylene, dissolved or Acetylene
PRODUCT IDENTIFICATION NUMBER (PIN): 1001
CLASSIFICATION: 2.1 - Flammable gas
SPECIAL PROVISIONS: 46,48,56,102,90,100,110
IMO CLASSIFICATION: 2.1
ICAO CLASSIFICATION: 2,3
PACKING GROUP: X
*** SECTION 15. REGULATORY INFORMATION ***
** WORKPLACE HAZARDOUS MATERIALS INFORMATION SYSTEM (WHMIS) **
PROPOSED WHMIS CLASSIFICATION:
A- Compressed gas
Bi - Flammable and combustible material - Flammable gas
WHMIS HEALTH EFFECTS:
Does not meet criteria
WHMIS INGREDIENT DISCLOSURE LIST:
Does not meet criteria
DETAILED WHMIS CLASSIFICATION ACCORDING TO CRITERIA:
CLASS A - COMPRESSED GAS: Meets criteria; critical temperature:
36 deg C
CLASS B - FLAMMABLE & COMBUSTIBLE MATERIAL: Meets criteria for
"Flammable gas'; explosive limits 2.5-81%; tdg class 2.1
CLASS C - OXIDIZING MATERIAL: Does not meet criteria
CLASS D - POISONOUS AND INFECTIONS MATERIALS. DIVISION 1 - IMME
DIATE AND SERIOUS TOXIC EFFECTS: Does not meet criteria
Acute Lethality: Foes not meet criteria. Simple asphyxiant.
CLASS D - POISONOUS AND INFECTIOUS MATERIAL. DIVISION 2- OTHER
TOXIC
EFFECTS: Does not meet criteria. Simple asphyxiant.
CLASS E - CORROSIVE MATERIAL: Does not meet criteria
CLASS F - DANGEROUSLY REACTIVE MATERIAL: Does not meet criteria
(acetylene dissolved in acetone in closed
cylinder); pure acetylene is unstable at high pressure and can
decompose violently when shocked or heated.
However, acetylene is normally transported, stored and handled in
a stable form which, in our opinion, does not meet criteria.
OSHA HAZARD COMMUNICATION EVALUATION:
Meet criteria for hazardous material, as defined by 29 CRF
1910.1200.
*** SECTION 16. OTHER INFORMATION ***
SELECTED BIBLIOGRAPHY:
(1) Criteria for a recommended standard. Occupational exposure to
acetylene. Washington, DC:U.S. Department of Health, Education,
and Welfare: Public Health Service; Centre for Disease Control;
National Institute for Occupational Safety and Health, 1976
(2) Braker, W.; Mossman, A.L. Acetylene. In: Matheson gas data
book. 6th edition. Lyndhurst, NJ,1980.p.1-8
(3) Sandmeyer E>E. Alipatic hydrocarbons. In: Clayton, G.D.;
Clayton,F.E., eds. Patty's industrial hygiene and toxicology. 3rd
revised edition. Vol.2B: toxicology. New York, NY; Toronto,
Ontario:John Wiley and Sons, Inc., 1982.p.3211-3213
(4) Verschueren K. Handbook of environmental data on organic
chemicals.
Van Nostrand Reinhold Company, 1983.p.154
(5) Handbook of compressed gases. 2nd ed. Van Nostrand Reinhold
Company, 1981. p. 247-254
(6) Davidson, B.M.Studies of intoxication II: the action of
acetylene.
Journal of Pharmacology and Experimental Therapeutics.
Vol.25,no.2(1925).p.119-135
(7) Fire protection guide to hazardous materials. 10th ed,Nation
al Fire Protection Association, 1991.p.49-17,325M-12,491M-9,491M-
9 491M-185,491M-183,491M-70,491M-129,491M-128,491M-127,491M-
110,491M-91,491M-67,491M-53,491M-181,491M50,491M-193,491M-35,491M-68,491M-135
(8)
Ruth, J.A. Odor thresholds and irritation levels of several
chemical substances: a review. Amercial Industrial Hygiene
Association. Vol.47(Mar.1985).p.A-142-A-143
(9) Jones, A.T. Fatal gassing in an acetylene manufacturing
plant.
Archives of Environmental Health. Voil.1(1960). p.417-421
(10) Bretherick, L. Bretherick's handbook of reactive chemical
hazards. 4th ed. Butterworths, 1990. p. 230-
234,953,214,1187,127,1419,1149,920,1342
(11) Patty's industrial hygiene and toxicology. 3rd ed. Vol.2C.
John Wiley & Sons, 1982.p.4054-4056
Information on chemicals reviewed in the CHEMINFO dtabase 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 : 1992-01-10
REVISION INDICATORS:
Acute exposure (inhalation): 1992-09
Emergency overview; 1992-09
NFPA(health); 1992-09
NFPA (flammability);1992-09
NFPA (reactivity); 1992-09
LEL; 1992-09
Auto temperature; 1992-09
Fire hazard comments; 1992-09
Fire fighting instructions; 1992-09
HANDLING AND STORAGE; 1992-09
PEL-TWA;1992-09
Sampling; 1992-09
Engineering controls; 1992-09
Respiratory guidelines; 1992-09
Stability; 1992-09
Conditions to avoid; 1992-09
TOXICOLOGICAL INFORMATION; 1992-09
WHMIS(proposed class);1992-09
OSHA EVALUATION; 1992-09
OTHER INFORMATION;1992-09
Trans PEL-TWA; 1993-04
ACETYLENE CYLINDERS IDENTIFICATION AND SOLVENTS
SAFETY WITH ACETYLENE
Description
When calcium carbide and water are mixed, acetylene and lime
sludge are produced.
Acetylene
Acetylene is gas, often referred to as C2H2: when in cylinders it
is known as DA (dissolved acetylene). Acetylene is colourless,
invisible, slightly lighter than air, non-toxic and does not
support life: it can cause asphyxiation. Industrial acetylene,
because it is slightly impure, smells like garlic.
Acetylene burns in air with a smoky flame: when burning it devel
ops a lot of heat at high temperature. Mixtures of acetylene and
air are very easy to ignite or explode, for example by spark,
small flame or hot spot.
- ventilate areas where acetylene may be present
- do not smoke
- do not produce sparks
- do not produce hot spots
- use only explosion-proof electrical equipment
- do not tolerate acetylene leaks
- avoid producing air/acetylene mixtures
- do not allow air to enter acetylene circuits
- purge air from acetylene circuits with nitrogen before
admitting acetylene
- before beginning maintenance work, purge acetylene cir
cuits with nitrogen
*When heated or compressed above normal operating limits,
acetylene may explode as a result of violent decomposition
- open high pressure valves slowly
- never heat a pipe or vessel containing acetylene
- avoid sudden pressurisation of acetylene
* Only certain materials are suitable for use with acetylene:
check with your supervisor that any materials you use are ap
proved.
Acetylene may form explosive compounds when in contact with some
materials eg.copper, silver, mercury.
- never use copper,silver, or mercury in acetylene plants.
Acetylene is unstable and cannot be stored at high pressure in
the same way as other gases, like oxygen and nitrogen, in normal
gas cylinders.
An acetylene cylinder is a medium pressure container filled with
a porous mass: acetylene is dissolved in a solvent which is held
in the porous mass.
The illustrations below explain by way of well known examples the
principles involved.
-Sparkling water: carbon dioxide dissolves in water under
pressure. When the pressure is released the carbon dioxide bub
bles off and the gas escapes. A solution of acetylene in a
solvent behaves similarly.
-Sponge: the porous mass in an acetylene cylinder behaves like
a sponge: it absorbs the solvent and holds it evenly distribut
ed.
-Acetylene cylinder: imagine a sponge inside a steel container
being filled with sparkling water under pressure.
Identification
If any attempt is made to fill acetylene into a cylinder designed
for another gas, there will be an immediate risk of explosion
inside the cylinder. Positive identification of acetylene cylin
ders is, therefore, essential - See Appendix I
All cylinders are stamped on the shoulder, a reinforced part of
the neck ring, with identification marks which will be explained
to you by your supervisor.
- these marks must never be removed or defaced.
- cylinders can only be filled if they carry the correct
identification marks.
* Examination
Cylinders cannot be filled before they have been properly exam
ined
-Externally. A satisfactory cylinder is neither soiled nor shows
any damage on the outside of the shell.
This damage may consist of dents, gouges, scorch marks, rust or
attack by chemicals.
- check visually that the cylinder is free from these defects
and where neck rings and foot rings are fitted that they are in
good condition.
- check visually and operationally that the correct type of
valve is fitted and that it is in good condition especially that
there are no sign of soot in the outlet.
Internally. Cylinders can be misused by the customer-either by
withdrawing gas too fast or by using the cylinder on its side so
that it contains too little solvent.
-solvent content must be checked by comparing actual weight of
cylinder with the tare weight stamped on it, making allowance for
ambient temperature and gas content(as measured by pressure
gauge).
-internal examinations are carried out by specially trained
personnel at regular intervals: evidence of this examination is
given by a special ring fitted on the valve shank.
- cylinders must not be filled when they are due for internal
examination.
Solvent
The solvent used in PAMAROX acetylene cylinders is acetone.
Solvents can be hazardous when improperly handled.
The properties, it is necessary to know, are as follows.
Acetone is a colourless liquid, with fragrant mint like odour; it
is flammable and narcotic in high concentrations. Headaches and
sickness may occur from prolonged inhalation.
- ensure ventilation is not blocked in places like acetone
storage/handling area.
Keep acetone drums or containers closed when not in use.
Hazards
The main hazard with acetylene in cylinders is the possibility if
decomposition of acetylene inside the cylinder:
this can happen with or without an external cause.
If you detect a hot cylinder-close the valve, spray the cylinder
with water, advise your supervisor.
|
