 PCO2

The pCO2, PCO2, formula_1or formula_2 is the partial pressure of carbon dioxide (CO2), often used in reference to blood but also used in oceanography to describe the partial pressure of CO2 in the ocean and in life support systems engineering and underwater diving to describe the partial pressure in a breathing gas.Usually, the arterial blood is the relevant context; the symbol for formula_2 in arterial blood is formula_4.