What is the minimum purity of CO2 specified by IS 15222?

The minimum purity required is 99.5 percent by volume (Clause 4.2).

What is the maximum allowed water content in fire-grade CO2?

The maximum water content is 0.015 percent by mass, which is equivalent to 150 parts per million (ppm) (Clause 4.3).

Which standard should the CO2 storage cylinders comply with?

The cylinders must conform to IS 7285 for seamless steel gas cylinders and be approved by the Chief Controller of Explosives (Clause 5.1).

Is CO2 extinguishing agent safe for use in occupied areas?

No, it is not breathable and displaces oxygen. It is considered life-threatening at extinguishing concentrations and requires stringent safety measures like pre-discharge alarms and evacuation time delays for use in occupied spaces.

IS 15222

: 2002

Carbon Dioxide as Fire Extinguishing Media for Fire Protection -Specification

CurrentSpecializedSpecificationFire Safety · Fire Fighting

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This standard specifies the requirements for carbon dioxide used as a fire extinguishing medium in fire protection systems. It covers the essential properties of the gas, such as purity, water content, and oil content, along with guidelines for its storage in cylinders, marking, and testing procedures.

Carbon Dioxide as Fire Extinguishing Media for Fire Protection -Specification

Quick Reference Values

Minimum CO2 Purity99.5 % by volume

Maximum Water Content0.015 % by mass (150 ppm)

Maximum Oil Content5 ppm by mass

Cylinder Filling Ratio0.667 kg/litre (for tropical climates)

Cylinder Test Pressure250 kgf/cm² (as per IS 7285)

Practical Notes

The maximum permissible water content (150 ppm) is critical to prevent the formation of carbonic acid (which is corrosive) and to avoid freezing of discharge nozzles during operation.

CO2 is an asphyxiant at the concentrations used for fire suppression (typically >34%). Therefore, systems in normally occupied spaces must include safety interlocks, pre-discharge alarms, and time delays to allow for safe evacuation.

Cylinders must be periodically inspected and hydrostatically tested as mandated by the Gas Cylinder Rules, administered by the Chief Controller of Explosives (CCOE/PESO).