INTRODUCTION. The absorption of carbon dioxide is mandatory in closed and semi-closed circle breathing systems. The elimination of CO2 from exhaled gases is achieved through chemical neutralization in transparent canisters containingabsorbent granules. The IS Can is an easy to use disposable absorber that has been developed specifically for clinical use during anesthesia to absorb carbon dioxide within an anesthetic breathing system. The IS Can cartridge must be used in conjunction with inspiratory CO2 monitoring.