Substance profile
Carbon Monoxide
Carbon Monoxide is a colorless gas and is odorless.
01 · Identification
What Carbon Monoxide is
Carbon Monoxide is a colorless gas and is odorless. It boils at -191 °C, melts at -205 °C, is soluble in water.
Under the GHS it carries the signal word Danger. It is classed as teratogens.
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 |
|---|---|
| H220 | Extremely flammable gas. |
| H360D | May damage the unborn child. |
| H331 | Toxic if inhaled. |
| H372 | Causes damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
Precautionary statements: P210, P233, P260, P270, P271, P304, P310, P314, P403
03 · Physical and chemical properties
Carbon Monoxide 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 | -191.5 °C (-312.7 °F) | HSDB | |
| -191.67 °C (-313 °F) | NIOSH | ||
| -191.5 °C (-312.7 °F) | at 760 mmHg | CAMEO | |
| Melting point | -205.02 °C (-337 °F) | HSDB | |
| -205 °C (-337 °F) | NIOSH | ||
| -198.89 °C (-326 °F) | CAMEO | ||
| Density | 0.301 g/cm³ | HSDB | |
| 0.7886 g/cm³ | HSDB | ||
| 0.929 g/cm³ | HSDB | ||
| Solubility | Soluble in benzene | HSDB | |
| 2% | NIOSH | ||
| Vapor pressure | 155000000 mmHg | at 25 °C | HSDB |
| 26600 mmHg | above this value | NIOSH | |
| Flash point | NA (Gas) | NIOSH | |
| Flammable gas | ICSC | ||
| Autoignition temperature | 700 °C (1292 °F) | HSDB | |
| 608.89 °C (1128 °F) | CAMEO | ||
| 605 °C (1121 °F) | ICSC | ||
| Lower explosive limit (LEL) | 12 % by volume | HSDB | |
| 12.5 % by volume | HSDB | ||
| Upper explosive limit (UEL) | 75 % by volume | HSDB | |
| 74.2 % by volume | HSDB | ||
| 74 % by volume | NIOSH | ||
| Vapor density | 0.968 (air = 1) | HSDB | |
| 0.97 (air = 1) | CAMEO | ||
| Critical temperature and pressure | -139 °C (-218.2 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Source notes
Further notes on Carbon Monoxide
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
Freely absorbed by a concentrated solution of cuprous chloride in hydrochloric acid or ammonium hydroxide; Appreciably soluble in some organic solvents, such as ethyl acetate, chloroform, acetic acid; solubility in methanol and ethanol about 7 times as great as in water.
Source: HSDB
05 · Handling and storage
Storing and handling Carbon Monoxide
Storage conditions
Store in a cool, dry, well-ventilated location.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
May react vigorously with oxygen, acetylene, chlorine, fluorine, nitrous oxide.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Carbon Monoxide in the storage compatibility matrix →