NICET Special Hazard Suppression Systems 3

Question 1

What does the acronym 'AFFF' stand for in fire suppression?

Accepted Answer

Aqueous Film Forming Foam

Answer

Automatic Fire and Foam Flow

Answer

Alcohol-Free Firefighting Foam

Answer

Advanced Fluorine Foam Formulation

Question 2

Class K fires, as defined by NFPA, involve which type of fuel?

Accepted Answer

Vegetable or animal cooking oils and fats in commercial cooking equipment

Answer

Combustible metals such as magnesium and sodium

Answer

Energized electrical equipment

Answer

Cryogenic liquids stored under pressure

Question 3

Which inert gas blend, designated IG-541, is marketed under the trade name 'Inergen' and consists of nitrogen, argon, and CO2?

Accepted Answer

IG-541 (52% N₂ / 40% Ar / 8% CO₂)

Answer

IG-01 (100% argon)

Answer

IG-55 (50% nitrogen / 50% argon)

Answer

IG-100 (100% nitrogen)

Question 4

In a CO2 total flooding system, the 'soaking period' refers to:

Accepted Answer

The duration the design CO2 concentration must be maintained after discharge to ensure complete fire extinguishment

Answer

The time required for CO2 to fully pressurize the cylinder bank before release

Answer

The mandatory pre-alarm warning time before agent release

Answer

The post-suppression ventilation period required before re-entry

Question 5

Regarding halon 1211 (bromochlorodifluoromethane) systems after the production phase-out under the Clean Air Act:

Accepted Answer

New halon 1211 systems are prohibited, but existing systems may be recharged with recovered or recycled halon

Answer

All existing halon 1211 systems must be immediately decommissioned

Answer

Halon 1211 production continues at reduced quotas for critical applications

Answer

Halon 1211 may only be used in marine vessel applications

Question 6

For a commercial cooking hood wet chemical system, nozzle placement must provide coverage of which combination of areas per NFPA 17A?

Accepted Answer

Cooking surface, hood plenum, and exhaust duct(s)

Answer

Cooking surface only

Answer

Exhaust duct and make-up air plenum only

Answer

Entire kitchen floor area and cooking surface

Question 7

What is the primary fire suppression mechanism of carbon dioxide (CO2) when used in a total flooding application?

Accepted Answer

Oxygen displacement — reducing O₂ concentration below the level that supports combustion

Answer

Chemical chain reaction interruption (breaking the fire tetrahedron)

Answer

Rapid cooling of the fuel surface below its ignition temperature

Answer

Physical barrier formation over the fuel surface