Chemical Datasheet
1-PROPYNE |
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Chemical Identifiers
The
Chemical Identifier fields
include common identification numbers, the
NFPA diamond
U.S. Department of Transportation hazard labels, and a general
description of the chemical. The information in CAMEO Chemicals comes
from a variety of
data sources.
CAS Number | UN/NA Number | DOT Hazard Label | USCG CHRIS Code |
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|
none | |
NIOSH Pocket Guide | International Chem Safety Card | ||
Methyl acetylene |
NFPA 704
Diamond | Hazard | Value | Description | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
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1 | Can cause significant irritation. | |||||||||
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4 | Burns readily. Rapidly or completely vaporizes at atmospheric pressure and normal ambient temperature. | ||||||||||
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3 | Capable of detonation or explosive decomposition or explosive reaction but requires a strong initiating source or must be heated under confinement before initiation. | ||||||||||
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(NFPA, 2010)
General Description
A colorless liquefied gas with a sweet odor. mp: -104°C, bp: -23.1°C. Insoluble in water, soluble in ethanol, chloroform and benzene. Moderately toxic by inhalation. Used as a specialty fuel. Denser than air. Vapors may ignite at distant sources of ignition and flash back.
Hazards
The
Hazard fields
include
special hazard alerts
air and water
reactions, fire hazards, health hazards, a reactivity profile, and
details about
reactive groups assignments
and
potentially incompatible absorbents.
The information in CAMEO Chemicals comes from a variety of
data sources.
Reactivity Alerts
- Highly Flammable
- Peroxidizable Compound
Air & Water Reactions
Highly flammable. PEROXIDE FORMING WHICH LEADS TO EXPLOSIONS
Fire Hazard
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966), Methane (UN1971) and Hydrogen and Methane mixture, compressed (UN2034) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. CAUTION: When LNG - Liquefied natural gas (UN1972) is released on or near water, product may vaporize explosively. (ERG, 2024)
EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966), Methane (UN1971) and Hydrogen and Methane mixture, compressed (UN2034) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. CAUTION: When LNG - Liquefied natural gas (UN1972) is released on or near water, product may vaporize explosively. (ERG, 2024)
Health Hazard
Excerpt from NIOSH Pocket Guide for Methyl acetylene
:
Exposure Routes: Inhalation, skin and/or eye contact (liquid)
Symptoms: Irritation respiratory system; tremor, hyperexcitability, anesthesia; liquid: frostbite
Target Organs: Respiratory system, central nervous system (NIOSH, 2024)
Exposure Routes: Inhalation, skin and/or eye contact (liquid)
Symptoms: Irritation respiratory system; tremor, hyperexcitability, anesthesia; liquid: frostbite
Target Organs: Respiratory system, central nervous system (NIOSH, 2024)
Reactivity Profile
1-PROPYNE is highly flammable. The liquid material in cylinders contains about 30% propadiene. Detonation may occur at 95°C [MCA Case History No. 632]. Reacts exothermically with many oxidizing agents and with some reducing agents as well. May react with silver, copper, and mercury salts in aqueous solution to give explosive acetylides. Incompatible with brass that contains more than 65% copper, with other copper-containing alloys, with Monel metal, with neoprene, polyethylene, and, to a lesser extent, with Teflon. May enflame in air in the presence of Co, Hg, Hg salts, K, Ag, Ag salts, RbH, CsH, halogens, HNO3, NaH. Can decompose explosively when compressed to 4.5 to 5.6 atmospheres. Moderate explosion hazard when exposed to heat or flame or by spontaneous chemical reaction. Has been known to decompose explosively at high pressures and moderate temperatures in the absence of air.
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents
Use caution: Liquids with this reactive group classification have been known to react with the absorbent listed below. More info about absorbents, including situations to watch out for...
- Dirt/Earth
Response Recommendations
The
Response Recommendation fields
include isolation and evacuation distances, as well as recommendations for
firefighting, non-fire response, protective clothing, and first aid. The
information in CAMEO Chemicals comes from a variety of
data sources.
Isolation and Evacuation
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
LARGE SPILL: Consider initial downwind evacuation for at least 800 meters (1/2 mile).
FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE - Safety Precautions" section. (ERG, 2024)
IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
LARGE SPILL: Consider initial downwind evacuation for at least 800 meters (1/2 mile).
FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. In fires involving Liquefied Petroleum Gases (LPG) (UN1075), Butane (UN1011), Butylene (UN1012), Isobutylene (UN1055), Propylene (UN1077), Isobutane (UN1969), and Propane (UN1978), also refer to the "BLEVE - Safety Precautions" section. (ERG, 2024)
Firefighting
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.).
SMALL FIRE: Dry chemical or CO2.
LARGE FIRE: Water spray or fog. If it can be done safely, move undamaged containers away from the area around the fire. CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.
FIRE INVOLVING TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)
DO NOT EXTINGUISH A LEAKING GAS FIRE UNLESS LEAK CAN BE STOPPED. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Hydrogen and Methane mixture, compressed (UN2034) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.).
SMALL FIRE: Dry chemical or CO2.
LARGE FIRE: Water spray or fog. If it can be done safely, move undamaged containers away from the area around the fire. CAUTION: For LNG - Liquefied natural gas (UN1972) pool fires, DO NOT USE water. Use dry chemical or high-expansion foam.
FIRE INVOLVING TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)
Non-Fire Response
Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:
ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors. Prevent spreading of vapors through sewers, ventilation systems and confined areas. Isolate area until gas has dispersed. CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning. (ERG, 2024)
ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. CAUTION: For LNG - Liquefied natural gas (UN1972), DO NOT apply water, regular or alcohol-resistant foam directly on spill. Use a high-expansion foam if available to reduce vapors. Prevent spreading of vapors through sewers, ventilation systems and confined areas. Isolate area until gas has dispersed. CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning. (ERG, 2024)
Protective Clothing
Excerpt from NIOSH Pocket Guide for Methyl acetylene
:
Skin: FROSTBITE - Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.
Eyes: FROSTBITE - Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.
Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift).
Remove: WHEN WET (FLAMMABLE) - Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100°F).
Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.
Provide: FROSTBITE WASH - Quick drench facilities and/or eyewash fountains should be provided within the immediate work area for emergency use where there is any possibility of exposure to liquids that are extremely cold or rapidly evaporating. (NIOSH, 2024)
Skin: FROSTBITE - Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.
Eyes: FROSTBITE - Wear appropriate eye protection to prevent eye contact with the liquid that could result in burns or tissue damage from frostbite.
Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift).
Remove: WHEN WET (FLAMMABLE) - Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100°F).
Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.
Provide: FROSTBITE WASH - Quick drench facilities and/or eyewash fountains should be provided within the immediate work area for emergency use where there is any possibility of exposure to liquids that are extremely cold or rapidly evaporating. (NIOSH, 2024)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
Excerpt from NIOSH Pocket Guide for Methyl acetylene
:
Eye: FROSTBITE - If eye tissue is frozen, seek medical attention immediately; if tissue is not frozen, immediately and thoroughly flush the eyes with large amounts of water for at least 15 minutes, occasionally lifting the lower and upper eyelids. If irritation, pain, swelling, lacrimation, or photophobia persist, get medical attention as soon as possible.
Skin: FROSTBITE - If frostbite has occurred, seek medical attention immediately; do NOT rub the affected areas or flush them with water. In order to prevent further tissue damage, do NOT attempt to remove frozen clothing from frostbitten areas. If frostbite has NOT occurred, immediately and thoroughly wash contaminated skin with soap and water.
Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible. (NIOSH, 2024)
Eye: FROSTBITE - If eye tissue is frozen, seek medical attention immediately; if tissue is not frozen, immediately and thoroughly flush the eyes with large amounts of water for at least 15 minutes, occasionally lifting the lower and upper eyelids. If irritation, pain, swelling, lacrimation, or photophobia persist, get medical attention as soon as possible.
Skin: FROSTBITE - If frostbite has occurred, seek medical attention immediately; do NOT rub the affected areas or flush them with water. In order to prevent further tissue damage, do NOT attempt to remove frozen clothing from frostbitten areas. If frostbite has NOT occurred, immediately and thoroughly wash contaminated skin with soap and water.
Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible. (NIOSH, 2024)
Physical Properties
The
Physical Property fields
include properties such as vapor pressure and
boiling point, as well as explosive limits and
toxic exposure thresholds
The information in CAMEO Chemicals comes from a variety of
data sources.
Note: For Vapor Density and Specific Gravity, comparing the value to 1.0 can tell you if the chemical will likely sink/rise in air or sink/float in fresh water (respectively). Short phrases have been added to those values below as an aid. However, make sure to also consider the circumstances of a release. The Vapor Density comparisons are only valid when the gas escaping is at the same temperature as the surrounding air itself. If the chemical is escaping from a container where it was pressurized or refrigerated, it may first escape and behave as a heavy gas and sink in the air (even if it has a Vapor Density value less than 1). Also, the Specific Gravity comparisons are for fresh water (density 1.0 g/mL). If your spill is in salt water (density about 1.027 g/mL), you need to adjust the point of comparison. There are some chemicals that will sink in fresh water and float in salt water.
Note: For Vapor Density and Specific Gravity, comparing the value to 1.0 can tell you if the chemical will likely sink/rise in air or sink/float in fresh water (respectively). Short phrases have been added to those values below as an aid. However, make sure to also consider the circumstances of a release. The Vapor Density comparisons are only valid when the gas escaping is at the same temperature as the surrounding air itself. If the chemical is escaping from a container where it was pressurized or refrigerated, it may first escape and behave as a heavy gas and sink in the air (even if it has a Vapor Density value less than 1). Also, the Specific Gravity comparisons are for fresh water (density 1.0 g/mL). If your spill is in salt water (density about 1.027 g/mL), you need to adjust the point of comparison. There are some chemicals that will sink in fresh water and float in salt water.
Chemical Formula: |
|
Flash Point: data unavailable
Lower Explosive Limit (LEL):
1.7 %
(NIOSH, 2024)
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point:
-153°F
(NIOSH, 2024)
Vapor Pressure:
5.2 atm
(NIOSH, 2024)
Vapor Density (Relative to Air):
1.41
(NIOSH, 2024)
- Heavier than air; will sink
Specific Gravity: data unavailable
Boiling Point:
-10°F
at 760 mmHg
(NIOSH, 2024)
Molecular Weight:
40.1
(NIOSH, 2024)
Water Solubility:
Insoluble
(NIOSH, 2024)
Ionization Energy/Potential:
10.36 eV
(NIOSH, 2024)
IDLH:
1700 ppm
; Based on 10% of the lower explosive limit.
(NIOSH, 2024)
AEGLs (Acute Exposure Guideline Levels)
No AEGL information available.ERPGs (Emergency Response Planning Guidelines)
No ERPG information available.PACs (Protective Action Criteria)
Chemical | PAC-1 | PAC-2 | PAC-3 | |
---|---|---|---|---|
Methyl acetylene (74-99-7) | 230 ppm | 2500 ppm ![]() |
15000 ppm ![]() |
LEL = 17000 ppm |


(DOE, 2024)
Regulatory Information
The
Regulatory Information fields
include information from
the U.S. Environmental Protection Agency's Title III Consolidated List of
Lists,
the U.S. Cybersecurity and Infrastructure Security Agency's Chemical Facility
Anti-Terrorism Standards,
and the U.S. Occupational Safety and Health Administration's
Process Safety Management of Highly Hazardous Chemicals Standard List
(see more about these
data sources).
EPA Consolidated List of Lists
Regulatory Name | CAS Number/ 313 Category Code |
EPCRA 302 EHS TPQ |
EPCRA 304 EHS RQ |
CERCLA RQ | EPCRA 313 TRI |
RCRA Code |
CAA 112(r) RMP TQ |
---|---|---|---|---|---|---|---|
1-Propyne | 74-99-7 | 10000 pounds | |||||
Propyne | 74-99-7 | 10000 pounds |
(EPA List of Lists, 2024)
CISA Chemical Facility Anti-Terrorism Standards (CFATS)
RELEASE | THEFT | SABOTAGE | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Chemical of Interest | CAS Number | Min Conc | STQ | Security Issue |
Min Conc | STQ | Security Issue |
Min Conc | STQ | Security Issue |
Propyne; [1-Propyne] | 74-99-7 | 1.00 % | 10000 pounds | flammable |
(CISA, 2007)
OSHA Process Safety Management (PSM) Standard List
No regulatory information available.Alternate Chemical Names
This section provides a listing of alternate names for this chemical,
including trade names and synonyms.
- ALLYLENE
- METHYL ACETYLENE
- METHYLACETYLENE
- PROPINE
- PROPYNE
- 1-PROPYNE