PRODUCT Properties
| Melting point: | -102.7 °C (lit.) |
| Boiling point: | -23.2 °C (lit.) |
| Density | 0.6070 |
| vapor pressure | 204.6 mm Hg ( −49.5 °C) |
| refractive index | 1.3863 |
| Flash point: | -51 °C |
| solubility | Soluble in alcohol, benzene, and chloroform (Weast, 1986) |
| form | gas |
| color | Colorless, flammable gas with a sweet odor |
| Water Solubility | 3,640 mg/L at 20 °C (quoted, Verschueren, 1983) |
| Henry's Law Constant | 0.11 at 25 °C (Hine and Mookerjee, 1975) |
| Exposure limits | NIOSH REL: TWA 1,000 ppm (1,650 mg/m3), IDLH 1,700 ppm; OSHA PEL:
TWA 1,000 ppm; ACGIH TLV: TWA 1,000 ppm (adopted). |
| InChIKey | MWWATHDPGQKSAR-UHFFFAOYSA-N |
| CAS DataBase Reference | 74-99-7(CAS DataBase Reference) |
| NIST Chemistry Reference | Propyne(74-99-7) |
| EPA Substance Registry System | Propyne (74-99-7) |
Description and Uses
Methyl acetylene is a flammable, colorless gas with a sweet odor. Molecular weight= 40.07;Boiling point=23.3℃; Freezing/Melting point=102.8℃; Vapor pressure= 5.2 atm; Relative vapor density (air= 1)= 1.41. Explosive limits: LEL= 1.7%; UEL= 11.7%. Hazard Identification (based on NFPA-704 M Rating System): Health 2, Flammability 4, Reactivity 2. A fuel that is shipped as a liquefied compressed gas. Practically insoluble in water; solubility 0.4%.
Propyne is produced by thermal or catalytic pyrolysis of propene. Like acetylene, propyne is used as a welding torch fuel, as a specialty fuel, and chemical intermediate.
Safety
| Symbol(GHS) |    GHS02,GHS04,GHS07 |
| Signal word | Danger |
| Hazard statements | H220-H280-H335 |
| Precautionary statements | P210-P410+P403 |
| Hazard Codes | F,Xi |
| Risk Statements | 11-37-43 |
| Safety Statements | 16-36-38-37 |
| RIDADR | UN 1954 2.1 |
| OEB | A |
| OEL | TWA: 1000 ppm (1650 mg/m3) |
| WGK Germany | - |
| RTECS | UK4250000 |
| HazardClass | 2.1 |
| PackingGroup | II |
| HS Code | 2901290000 |
| Hazardous Substances Data | 74-99-7(Hazardous Substances Data) |
| IDLA | 1,700 ppm [10% LEL] |
