| Physical Description |
Ethylene appears as a colorless gas with a sweet odor and taste. It is lighter than air. It is easily ignited and a flame can easily flash back to the source of the leak. Under prolonged exposure to fire or heat the containers may rupture violently and rocket. Can cause explosion. |
| Color/Form |
Colorless gas |
| Odor |
Sweet |
| Taste |
Tasteless |
| Boiling Point |
-154.7 °F at 760 mmHg (USCG, 1999) |
| Melting Point |
-272.4 °F (USCG, 1999) |
| Flash Point |
-213 °F (approx.) (USCG, 1999) |
| Solubility |
In water, 131 mg/L at 25 °C |
| Density |
0.569 at -154.84 °F (USCG, 1999) - Less dense than water; will float |
| Vapor Density |
0.98 (Air = 1) |
| Vapor Pressure |
Vapor pressure 4,040 kPa (-1.5 °C) |
| LogP |
log Kow = 1.13 |
| Henry's Law Constant |
Henry's Law constant = 0.228 atm-cu m/mole at 25 °C |
| Stability/Shelf Life |
Stable under recommended storage conditions. |
| Autoignition Temperature |
842 °F (USCG, 1999) |
| Decomposition |
Hazardous decomposition products formed under fire conditions: Carbon oxides. |
| Viscosity |
0.01 mPa.s 20 °C |
| Corrosivity |
Ethylene is a noncorrosive gas. |
| Heat of Combustion |
-1411.2 kJ/mol (gas) |
| Heat of Vaporization |
13.53 kJ/mol at -103.77 °C |
| Surface Tension |
16 dynes/cm = 0.016 N/m at -104 °C |
| Polymerization |
Hazardous polymerization may occur. |
| Odor Threshold |
Odor Threshold Low: 17.0 [ppm] Odor Threshold High: 959.0 [ppm] [ACGIH] Detection odor threshold from AIHA (mean = 270 ppm) |
| Refractive Index |
Index of refraction: 1.363 at -100 °C/D |
| Kovats Retention Index |
178.1 164 166 158 178 166 166 165 165 165 165 165 188 |
| Other Experimental Properties |
Monoclinic prisms when it solidifies at -181 °C |
| Chemical Classes |
Toxic Gases & Vapors -> Simple Asphyxiants |
