An introduction about Clean Agent (FK-5-1-12) as a fire extinguishment gaseous system
Yasser Amer Ahmed, PMSFPE
FK-5-1-12 as a clean extinguishing agent
• is a ‘compartment’ and ‘local application’ fire protection system.
• must be designed to ensure extinguishment.
• performance greatly depends on the ventilation and sealing of the compartment it is protecting.
• has good environmental credentials.
• will produce hydrogen fluoride in a fire which can be harmful to personnel and damaged equipment.
What is (FK-5-1-12)?
(FK-5-1-12) was developed as a halon replacement and hydrofluorocarbon (HFC) alternative. It belongs to a family of chemicals called halocarbons, a group that includes HFCs and fluoro-ketones. (FK-5-1-12) is a C-6 Fluoro-ketone (full name: dodecafluoro-2-methylpentan-3-one) with a boiling point of 49.2°C.
(FK-5-1-12) systems can be used for compartment protection and local application on specific hazards.
How it works
In a typical total flooding system, the fluid is stored as a liquid in cylinders pressurized with nitrogen. (FK-5-1-12) has a discharge duration of around 10 seconds at a pressure of (10 bar).
(FK-5-1-12) is stored as a liquid but discharges as a gas. Storage of the liquid requires the storage cylinders to be in close proximity to the protected compartment/area.
(FK-5-1-12) works by distributing the gas uniformly throughout the enclosure, absorbing the heat output from the flames quicker than the fire can produce.
Systems may be automatically or manually activated. The system will be designed to shut down any air conditioning system, close openings, and doors, and control all sources of oxygen and fuel (energy) prior to discharge.
Challenges and considerations
(FK-5-1-12) can be an effective fire protection system that extinguishes fire and prevents re-ignition. The raw agent, at typical fire protection use concentrations, presents no risk to people or damage to equipment when engineered and installed by a competent qualified fire suppression systems installation company. The No Observable Adverse Effects Level (NOAEL) and Lowest Observable Adverse Effects Level (LOAEL) of the raw agent are 10% and >10% respectively. Under the action of fire, hydrogen fluoride, a highly toxic and corrosive acidic gas is a by-product of its extinguishing action. The amount of hydrogen fluoride is a function of the fire size and generated concentrations can be significant when considering human exposure and this must be appreciated in the fire safety management plan. Hydrogen fluoride forms a very aggressive corrosive acid when dissolved in water and can damage any exposed metals and/or glass. Similarly, the release of any gaseous agent within a fire compartment will cause the mixing of agents and fire products at all levels within the enclosure, which might impair escape through loss of visibility, acid gas irritation, and inhalation of toxic products such as CO and CO2.
Applicable Design Standards
• NFPA 2001:2018 Standard on clean agent fire extinguishing systems.
• F.M. Global D-S 4.9 Halocarbon and Inert gas (clean agent) Fire extinguishment systems 2019.
• UL 2166:2019 Standard for Halocarbon Clean Agent Extinguishing System Units.
• ISO 14520-1 International Standard
• VDS 2381 / CEA 4045
Effective for use with:
• Laboratories/telecommunication rooms
• Computer and server environments
• Control rooms/archive storage
• Halon replacement
• Conventional detection systems
• Class A, Class B, and Class C Fires
• Electrical equipment (non-conductive)
• Shipbuilding and oil platforms.
Has limitations in relation to:
• Class D Fires
• Combustible metals (Sodium, Potassium, Magnesium, etc.)
• Chemicals containing their own oxygen supply, such as cellulose nitrate
• Requires the enclosure to be gas tight
• Requires the air conditioning and openings to be closed/shut down on detection
• Where equipment is sensitive to acid gases (hydrogen fluoride)
• Pressure relief is required during discharge.
Best uses applications of (FK-5-1-12)
‘Asset protection’ – (FK-5-1-12) is generally designed as an extinguishing system for use in business-critical areas to protect specific assets from fire damage (e.g., server rooms and data centers).
‘Life Safety’ – Not installed for life safety, however, as a full system inclusive of the fire detection system, it can aid in early detection and evacuation.
‘Property protection’ – Will only be considered as an extinguishment system. Failure of extinguishment and the fire will rekindle and continue unopposed potentially producing prolific quantities of hydrogen fluoride.
Environmental credentials
(FK-5-1-12) has a global warming potential of 1 and an ozone depletion potential of 0. It has a 5-day atmospheric lifetime and a 30-year shelf life, satisfying current environmental and safety standards. (FK-5-1-12) does not fall under the European F-gas Regulations. At the end of the lifetime of the system, the fluid can be readily recovered and recycled.
