Carbon dioxide (CO₂) and carbon monoxide (CO) are two gaseous compounds containing carbon and oxygen. Yet, they differ significantly in their chemical structures, formation pathways, biological roles, environmental impacts, and effects on living organisms. Both gases are commonly present in the environment and play important roles in atmospheric chemistry, combustion processes, respiration, and metabolic cycles.
Carbon dioxide is a naturally occurring gas essential to biological processes such as photosynthesis and respiration, and to the regulation of Earth’s temperature through the greenhouse effect. In contrast, carbon monoxide is a toxic gas formed primarily from the incomplete combustion of carbon-based fuels. It interferes with oxygen transport in the bloodstream and poses serious health risks. Carbon dioxide (CO₂) is a colourless, odourless, and non-flammable gas composed of one carbon atom bonded to two oxygen atoms. It is naturally produced through respiration, decomposition, volcanic activity, and combustion.
Carbon dioxide contributes to:
Carbon monoxide (CO) is a colourless, odourless, and highly toxic gas consisting of one carbon atom and one oxygen atom. It is mainly formed during the incomplete combustion of carbon-containing substances.
Exposure to high levels may result in:
(Session 2026 - 27)