Substance profile
Propylene Oxide
Propylene Oxide is a colorless liquid with an odor is sweet, alcoholic, & like ether or benzene.
01 · Identification
What Propylene Oxide is
Propylene Oxide is a colorless liquid with an odor is sweet, alcoholic, & like ether or benzene. Its molecular formula is C3H6O and its molecular weight is 58.08 g/mol. It boils at 34.2 °C, melts at -112 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
Other names for Propylene Oxide
- 1,2-epoxypropane
- methyloxirane
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H224 | Extremely flammable liquid and vapour. |
| H350 | May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H340 | May cause genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H331 | Toxic if inhaled. |
| H311 | Toxic in contact with skin. |
| H302 | Harmful if swallowed. |
| H335 | May cause respiratory irritation. |
| H319 | Causes serious eye irritation. |
Precautionary statements: P201, P210, P233, P241, P242, P260, P264, P270, P271, P280, P301, P302, P304, P305, P308, P310, P312, P313, P330, P337, P338, P352, P403
03 · Physical and chemical properties
Propylene Oxide properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 34.23 °C (93.6 °F) | HSDB | |
| 34.44 °C (94 °F) | NIOSH | ||
| 34.23 °C (93.6 °F) | at 760 mmHg | CAMEO | |
| Melting point | -112.13 °C (-169.8 °F) | HSDB | |
| -112.22 °C (-170 °F) | NIOSH | ||
| Density | 0.8304 g/cm³ | HSDB | |
| 0.83 g/cm³ | NIOSH | ||
| Solubility | MISCIBLE WITH ACETONE, BENZENE, CARBON TETRACHLORIDE, METHANOL, & ETHER | HSDB | |
| Solubility of water in propylene oxide is 12.8% by wt at 20 °C. | at 20 °C | HSDB | |
| 40.5 wt% water @ 20 °C | at 20 °C | HSDB | |
| Vapor pressure | 445 mmHg | NIOSH | |
| 445 mmHg | at 20 °C | CAMEO | |
| 538 mmHg | at 25 °C | HSDB | |
| Flash point | -37.22 °C (-35 °F) | HSDB | |
| Autoignition temperature | 449 °C (840.2 °F) | HSDB | |
| 465 °C (869 °F) | CAMEO | ||
| 430 °C (806 °F) | ICSC | ||
| Lower explosive limit (LEL) | 2.3 % by volume | HSDB | |
| 2.1 % by volume | HSDB | ||
| Upper explosive limit (UEL) | 36 % by volume | HSDB | |
| 38.5 % by volume | HSDB | ||
| Vapor density | 2 (air = 1) | HSDB | |
| Odor threshold | Inasmuch as the detectable odor concn of propylene oxide is reported to be as high as 200 ppm, its odor cannot be reliably used as a warning. | HSDB | |
| Odor detection in air= 9.90x10+0 ppm | Purity not specified | HSDB | |
| Odor recognition in air= 3.50x10+1 ppm | Purity not specified | HSDB | |
| Critical temperature and pressure | 209.1 °C (408.4 °F) | HSDB | |
| Corrosivity | NONCORROSIVE TO METALS | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Propylene Oxide
Storage conditions
Use glass or metal containers sealed with nitrogen.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
No acetylide-forming metals such as copper or copper alloys should be in contact with propylene oxide.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
PROPYLENE OXIDE react with oxidizing agents and strong acids (NTP, 1992). Reacts with Grignard reagents and organolithium compounds. An explosion occurred when propylene oxide was added to an epoxy resin. It was concluded that polymerization was catalyzed by an amine accelerator in the resin [Bretherick, 5th Ed., 1995]. Underwent polymerization when mixed with sodium hydroxide causing ignition and explosion of a drum of the crude product. [Combust Sci. Technol., 1983].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Propylene Oxide in the storage compatibility matrix →