- Methyl acetylene
Colorless gas with a sweetish odor.
Welding torch fuel, chemical synthesis.
Registry Numbers and Inventories.
S 9 16 23 33
Swiss Giftliste 1
Japan ENCS (MITI)
Melting point, °C
Boiling point, °C
Vapor pressure, mmHg
3876 (20 C)
Vapor density (air=1)
0.6447 g/cm3 (-1 C)
Solubility in water
8.4x10-3 MPa-s (25 C)
22.61 g/s2 (-37 C)
1.3863 (-40 C)
Partition coefficient, pKow
Heat of vaporization
Heat of combustion
Hazards and Protection.
Outside storage in cool, well-ventilated area is advised.
Store and handle in accordance with all current regulations and standards. Subject to storage regulations: U.S. OSHA 29 CFR 1910.101. Keep separated from incompatible substances.
Wear appropriate clothing to prevent any reasonable probability of skin contact. Wear eye protection to prevent any possibility of eye contact.
Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive pressure mode. Any supplied-air respirator with a full face piece and operated in pressure-demand or other positive pressure mode in combination with an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive pressure mode. Any appropriate escape-type, self-contained breathing apparatus.
Make no contact with the spilled material. ELIMINATE all ignition sources, combustibles and ground all equipment. Take up with sand or other noncombustible absorbent material and place into containers for later disposal.
React vigorously with strong oxidizing materials, reaction with silver nitrate forms acetylide igniting at 150 C.
Can decompose explosively at 4.5 To 5.6 atmospheres of pressure.
Upper exp. limit, %
Lower exp. limit, %
Stop flow of gas
Dangerous, when exposed to heat or flame induced decomposition of the endothermic hydrocarbon leads to flame propagation in absence of air above minimum pressures of 3. 4 And 2. 1 Bar at 20 and 120 C, respectively.
Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Containers may explode when heated.
Toxic gases and vapors (such as carbon monoxide) may be released in a fire involving methyl acetylene.
TLV: 1000 ppm; 1640 mg/m3 (ACGIH 1996). OSHA PEL: TWA 1000 ppm (1650 mg/m3) NIOSH REL: TWA 1000 ppm (1650 mg/m3) NIOSH IDLH: 1700 ppm LEL
Rapid breathing and rapid heart rate are common. In severe cases abnormally low blood pressure, apnea, and cardiac arrest develop. Various disturbances including headache, dizziness, mood disturbances, numbness of the extremities, sleepiness, mental confusion, poor judgement and coordination, and memory loss may occur. Prolonged or severe hypoxia results in unconsciousness. Prolonged asphyxia may produce CNS injury. Hemiparesis has been reported with volatile substance abuse. Cerebral edema with brainstem herniation may occur. Seizures have been reported following intentional inhalation.
Nausea, vomiting, and gastrointestinal hemorrhage may develop.
Hyperventilation may develop.
Dermal exposure may cause frostbite injury. Severe tissue burns have been reported.
Decreases in night vision, visual acuity, and visual fields (tunnel vision) may occur. Frothy mucous may be seen.
Seek medical assistance.
Administer 100% humidified supplemental oxygen with assisted ventilation as required. If hypoxia has been severe or prolonged, carefully evaluate for neurologic sequelae and provide supportive treatment as indicated. Pulmonary edema (noncardiogenic): maintain ventilation and oxygenation and evaluate with frequent arterial blood gas or pulse oximetry monitoring. E
Rewarming and a variety of topical treatments are indicated for frostbite injury. See main section for more information.
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.
USCG CHRIS Code