Substance profile
Morpholine
Morpholine is a colorless liquid with a characteristic amine odor.
01 · Identification
What Morpholine is
Morpholine is a colorless liquid with a characteristic amine odor. Its molecular formula is C4H9NO and its molecular weight is 87.12 g/mol. It boils at 128 °C, melts at -4.8 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
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 |
|---|---|
| H226 | Flammable liquid and vapour. |
| H332 | Harmful if inhaled. |
| H312 | Harmful in contact with skin. |
| H302 | Harmful if swallowed. |
| H314 | Causes severe skin burns and eye damage. |
Precautionary statements: P210, P233, P241, P242, P260, P270, P271, P280, P301, P302, P304, P310, P312, P330, P331, P352, P403
03 · Physical and chemical properties
Morpholine 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 | 128 °C (262.4 °F) | HSDB | |
| 128.89 °C (264 °F) | NIOSH | ||
| 128.89 °C (264 °F) | at 760 mmHg | CAMEO | |
| Melting point | -4.8 °C (23.4 °F) | HSDB | |
| -5 °C (23 °F) | NIOSH | ||
| -4.89 °C (23.2 °F) | CAMEO | ||
| Density | 1.007 g/cm³ | NIOSH | |
| 1.007 g/cm³ | at 20 °C | HSDB | |
| 0.9994 g/cm³ | at 20 °C | HSDB | |
| Solubility | Solluble in organic solvents | HSDB | |
| In water, 1.00X10+6 mg/L | miscible | HSDB | |
| Vapor pressure | 6 mmHg | NIOSH | |
| 6.6 mmHg | at 20 °C | CAMEO | |
| 10.1 mmHg | at 25 °C | HSDB | |
| Flash point | 35 °C (95 °F) | closed cup | HSDB |
| 36.67 °C (98 °F) | NIOSH | ||
| 37.78 °C (100 °F) | CAMEO | ||
| Autoignition temperature | 310 °C (590 °F) | anhydrous | HSDB |
| 310 °C (590 °F) | CAMEO | ||
| Lower explosive limit (LEL) | 1.4 % by volume | HSDB | |
| Upper explosive limit (UEL) | 11.2 % by volume | HSDB | |
| Vapor density | 3 (air = 1) | HSDB | |
| Odor threshold | Air: 0.01 ppm (v/v) | HSDB | |
| Odor Threshold Low: 0.01 [ppm] | Haz-Map | ||
| Critical temperature and pressure | 344 °C (651.2 °F) | HSDB | |
| Corrosivity | Corrosive to metals | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Source notes
Further notes on Morpholine
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Solubility
Immiscible with concn sodium hydroxide soln; miscible with acetone, benzene, ether, castor oil, methanol, ethanol, ethylene glycol, 2-hexanone, linseed oil, turpentine, pine oil; miscible with water with evolution of some heat
Source: HSDB
Odor
The absolute and recognition threshold odor index of 101 petrochemicals /were tested/ using a trained panel. During a 20 min exposure, 0.036 mg morpholine/cu m was recognized by 50% of the panel and 0.5 mg morpholine/cu m by all of the panel (giving an odor index of 65.9). It was described as an unpleasant fishy smell.
Source: HSDB
05 · Handling and storage
Storing and handling Morpholine
Storage conditions
Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Morpholine must be stored to avoid contact with strong acids, such as nitric acid, and strong oxidizers, such as chlorine dioxide, bromine, nitrates, and permanganates, since violent reactions occur.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Violent reaction and fire may result when the product is mixed with oxidizing agents, such as perchlorates, nitrates, permanganates, chromates, nitric acid, halogens, peroxides, and some cleaning solutions containing acids.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
MORPHOLINE neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. May generate hydrogen, a flammable gas, in combination with strong reducing agents such as hydrides. Sensitive to moisture. Reacts readily with oxidizing agents (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Morpholine in the storage compatibility matrix →