Carbon dioxide
Carbon dioxide is a one-carbon compound with formula CO2 in which the carbon is attached to each oxygen atom by a double bond. A colourless, odourless gas under normal conditions, it is produced during respiration by all animals, fungi and microorganisms that depend directly or indirectly on living or decaying plants for food. It has a role as a vasodilator agent, an anaesthetic, a solvent, an antagonist, a mouse metabolite, a Saccharomyces cerevisiae metabolite, a member of greenhouse gas, an Escherichia coli metabolite, a human metabolite, a member of food packaging gas, a food propellant and a refrigerant. It is a gas molecular entity, a carbon oxide and a one-carbon compound.
IUPAC: carbon dioxide
PubChem
Physical & Chemical Properties
| Melting Point | -109.3 °F (USCG, 1999) |
| Boiling Point | Sublimes (NIOSH, 2024) |
| Density | 1.56 at -110.2 °F (USCG, 1999) - Denser than water; will sink |
| Solubility | 0.2 % at 77 °F (NIOSH, 2024) |
| Flash Point | Not applicable |
| Vapor Pressure | 56.5 atm (NIOSH, 2024) |
| pH | The pH of saturated CO2 solutions varies from 3.7 at 101 kPa (1 atm) to 3.2 at 2370 kPa (23.4 atm) |
| Appearance | Carbon dioxide appears as a colorless odorless gas at atmospheric temperatures and pressures. Relatively nontoxic and noncombustible. Heavier than air and may asphyxiate by the displacement of air. Soluble in water. Forms carbonic acid, a mild acid. Under prolonged exposure to heat or fire the container may rupture violently and rocket. Used to freeze food, to control chemical reactions, and as a fire extinguishing agent. |
Data: PubChem · Last updated: 4/20/2026
GHS Classification
No GHS classification data available.
Classification data is sourced from ECHA.
Regulatory Compliance
Listed
note: Status based on EPA TSCA Active Inventory · inventory name: TSCA Chemical Substance Inventory
View sourceGlobal Trade Intelligence
No trade flow data available for this chemical.
HS Code(s): 2811
Data: UN Comtrade
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