This standard specifies the requirements for the design, installation, operation, testing, and maintenance of IG-100 gaseous fire extinguishing systems. These systems use 100% Nitrogen to suppress fires by reducing the oxygen concentration in a protected enclosure, making them suitable for areas where water or other agents would damage sensitive assets.
Gaseous Fire Extinguishing Systems - IG 100 Extinguishing Systems
Quick Reference Values
Agent Composition100% Nitrogen (N2)
Typical Design Concentration (Class A Surface Fire)37.5% volume
Resulting Oxygen Concentration (at 37.5% IG-100)13.1% volume
NOAEL (No Observed Adverse Effect Level)43% concentration (12% O2)
LOAEL (Lowest Observed Adverse Effect Level)52% concentration (10% O2)
Maximum Discharge Time (Surface Fires)60 seconds
Minimum Concentration Holding Time10 minutes
Key Formulas
W = (V/S) * [C / (100 - C)] — Formula for calculating the mass of extinguishing agent required, where V is volume, S is specific volume, and C is design concentration.
Practical Notes
Room integrity is critical for system effectiveness. A Door Fan Test (as described in Annex D) must be conducted to ensure the enclosure can hold the required gas concentration for a minimum of 10 minutes.
The system design must ensure the resulting oxygen concentration does not fall below 12% in normally occupied areas (NOAEL) to allow for safe egress of personnel.
Proper integration with building management systems is essential for automatically shutting down HVAC systems and closing dampers prior to gas discharge to prevent agent loss.