What is the NOAEL for CF3I and why is it important?

The No-Observed-Adverse-Effect Level (NOAEL) is 0.2% by volume. It's the maximum concentration to which humans can be exposed without adverse effects, making it a critical safety limit for system design (Table B.1).

What is the maximum discharge time for a CF3I system?

For most hazards, the system must discharge 95% of the required agent quantity within 10 seconds (Clause 6.6.3).

Can this agent be used in normally occupied spaces?

Use in normally occupied spaces is highly restricted. The design concentration must remain below the very low NOAEL of 0.2%, which is often insufficient for fire suppression (Clause 5).

What is the typical design concentration for a Class A fire hazard?

A minimum design concentration of 3.2% by volume is specified for Class A surface fire hazards (Table 2).

IS 15821

: 2008

Gaseous fire extinguishing systems - Physical properties and system design - CF3I extinguishant

CurrentSpecializedCode of PracticeBIMFire Safety · Fire Fighting

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This standard specifies requirements for total flooding fire extinguishing systems using Iodotrifluoromethane (CF3I) as the extinguishing agent. It covers the agent's physical properties, system design criteria, safety precautions for personnel, installation procedures, and maintenance.

Gaseous fire extinguishing systems - Physical properties and system design - CF3I extinguishant

Quick Reference Values

No-Observed-Adverse-Effect Level (NOAEL)0.2% by volume

Lowest-Observed-Adverse-Effect Level (LOAEL)0.4% by volume

Boiling Point at 1.013 bar-22.5 °C

Design Concentration for Class A Surface Fire3.2% by volume

Maximum Discharge Time10 seconds

Agent Storage Pressure (typical)25 bar at 21°C

Key Formulas

W = (V/s) * [c / (100 - c)] — Agent weight calculation, where V is volume, s is specific volume factor, and c is design concentration.

Practical Notes

CF3I has a very low No-Observed-Adverse-Effect Level (NOAEL) of 0.2%, which severely restricts its application in normally occupied spaces.

A mandatory Room Integrity Test is crucial to verify that the protected enclosure can hold the required agent concentration for the specified soaking time.

CF3I is an environmentally acceptable Halon 1301 replacement (zero ODP) but is less commonly used than other clean agents like FK-5-1-12 or HFC-227ea due to its low toxicological safety margin.