New Mexico CID MS-14 Dry Chemical Fire Protection Examination

Under NFPA 2001 (2008), a clean agent is best described as an extinguishing medium that:

• ALeaves a soapy film that must be washed from cooking equipment
• BIs electrically conductive and intended only for Class D metal fires
• CIs volatile or gaseous and leaves no residue that requires cleanup after discharge
• DIs a dry powder stored only in cartridge-operated hand extinguishers

Which standard is the primary design and installation reference for clean-agent fire-extinguishing systems on the MS-14 exam?

• ANFPA 12
• BNFPA 17
• CNFPA 2001
• DNFPA 13

Most listed clean-agent systems protect a room by which application method?

• ALocal application that coats only the burning surface
• BHose-stream application from a portable cylinder
• CLow-expansion foam discharge across an open tank
• DTotal flooding of an enclosure to a design concentration

Why does NFPA 2001 require a clean-agent hold time after discharge?

• ATo give the building sprinkler system time to start flowing water
• BTo keep the design concentration long enough to finish extinguishment and prevent reignit…
• CTo allow the abort switch to reset the cylinders automatically
• DTo cool the agent storage tanks before they can be refilled

In NFPA 2001 toxicology tables, NOAEL means:

• AThe lowest concentration at which an adverse effect has been observed
• BThe agent concentration remaining after a 10-minute hold time
• CThe minimum extinguishing concentration measured in a cup-burner test
• DThe highest concentration at which no adverse toxicological or physiological effect has b…

LOAEL for a clean agent is:

• AThe lowest concentration at which an adverse effect has been observed
• BThe maximum permitted leakage area of the enclosure
• CThe oxygen concentration remaining after an inert-gas discharge
• DThe factory-fill pressure of the agent cylinder

For a normally occupied enclosure, NFPA 2001 expects the clean-agent design concentration to:

• AExceed LOAEL so the fire is knocked down faster
• BEqual the cup-burner extinguishing concentration with no safety factor
• CRemain at or below the agent's NOAEL so occupants are not exposed above the no-effect lev…
• DBe at least 34 percent by volume regardless of the agent

How do inert-gas clean agents extinguish fire compared with typical halocarbon clean agents?

• AInert gases reduce oxygen in the enclosure; halocarbons absorb heat and interrupt the fla…
• BInert gases saponify grease; halocarbons freeze the fuel surface
• CBoth agents work only by coating the fuel with a dry powder
• DHalocarbons reduce oxygen to about 8 percent; inert gases leave a conductive film

What is the intended function of an abort switch on a clean-agent releasing system?

• APermanently silence the building fire-alarm horns
• BBypass supervision of the releasing circuit for the rest of the shift
• CClose the agent-cylinder valves after a completed discharge
• DDelay or prevent agent discharge only while the switch is held operated

A predischarge alarm on a clean-agent system is provided primarily to:

• AStart the kitchen exhaust fan
• BWarn occupants to leave before the agent discharges
• COpen pressure-relief vents after the hold time ends
• DReset cross-zoned smoke detectors

NFPA 2001 design concentration is obtained by:

• AUsing the raw cup-burner or extinguishing concentration with no increase
• BAlways using 34 percent by volume for every clean agent
• CIncreasing the extinguishing concentration by the standard's listed safety factor
• DMatching the cylinder fill ratio to the room's ceiling height only

For a typical clean-agent total-flooding enclosure, NFPA 2001 (2008) requires the agent concentration to be held for:

• A30 seconds, matching a halocarbon discharge time
• BOnly until the predischarge timer expires
• COne hour, regardless of the hazard
• DA minimum of 10 minutes, or a longer time if needed for trained personnel to respond, and…

A door-fan or room-integrity test on a clean-agent enclosure is performed to:

• AMeasure the hydrostatic test pressure of the agent cylinders
• BConfirm that enclosure leakage will still allow the required hold time at the design conc…
• CVerify that every nozzle orifice is drilled to the same diameter
• DCalibrate the abort-switch time-delay relay

On clean-agent discharge, HVAC systems serving the enclosure are generally required to:

• AShut down or close dampers so supply and exhaust air do not dump the agent out of the room
• BIncrease outdoor-air makeup so the agent mixes faster
• CSwitch to 100 percent exhaust for the entire 10-minute hold time
• DKeep running at design airflow because clean agents need continuous ventilation

Under NFPA 2001 (2008), how do required discharge times compare for halocarbon and inert-gas clean agents?

• ABoth agent families must reach 95 percent of design concentration in not more than 10 sec…
• BBoth agent families are allowed 10 minutes to discharge
• CInert-gas agents must discharge in 10 seconds; halocarbons are allowed 60 seconds
• DHalocarbon agents must reach 95 percent of design concentration in not more than 10 secon…

Why might a clean-agent enclosure need pressure-relief venting?

• ATo keep the wet-chemical tank at kitchen hood pressure
• BTo vent Halon 1301 to atmosphere after every annual inspection
• CTo limit peak enclosure pressure during the rapid agent discharge so walls, doors, or win…
• DTo provide makeup air while the hold time is running

Operating a listed manual-release station on a clean-agent system should:

• ASilence notification appliances and abort the release permanently
• BInitiate the release sequence, including required predischarge warning, unless the listin…
• COpen all HVAC dampers so the room can be purged
• DOnly illuminate a lamp on the cylinder rack

Cross-zoned smoke detection is used on many clean-agent releasing systems so that:

• AA single detector in alarm immediately dumps the entire agent bank
• BThe abort switch is no longer required
• CHeat detectors can be omitted from every NFPA 72 system
• DTwo independent detectors or zones must confirm the fire before the release sequence proc…

NMAC 14.6.6 MS-14 work includes incidental 24-volt controls. On a clean-agent or chemical system those controls most often:

• AEnergize listed solenoids or actuators that open container valves and trip safety shutoffs
• BReplace the need for a listed releasing control unit
• CAre permitted to be spliced with 120-volt lighting circuits in the same device box
• DProvide the only required supervision of agent quantity

For an existing Halon 1301 total-flooding system, NFPA 12A (2009) expects the contractor to:

• AVent unused Halon 1301 to atmosphere during every semiannual test
• BTreat the agent as an ozone-depleting substance that must be recovered and recycled, not…
• CConvert the cylinders to wet chemical and reuse the same nozzles over a fryer
• DIgnore enclosure integrity because Halon does not require a hold time

How is agent typically stored in the pressurized containers used on these systems?

• AHalocarbon clean agents as liquefied compressed gas, often superpressurized with nitrogen…
• BInert-gas agents as a premixed wet-chemical solution
• CHalocarbon agents as refrigerated bulk liquid at 0°F only
• DAll clean agents as dry powder with a cartridge of carbon dioxide

A clean-agent total-flooding system is a poor choice for which hazard?

• AAn enclosed server or control room that can be sealed
• BA normally occupied archives vault designed below the agent's NOAEL
• CAn unenclosed commercial fryer line that produces grease-laden vapors
• DA sealed telecommunication switch room

Agent-storage containers for a clean-agent system should be located so that:

• AThey are exposed to the highest temperature in the building to raise discharge pressure
• BThey remain within the temperature range stated on the nameplate and listing
• CThey are stored outdoors and uncovered in direct sun to simplify refill access
• DThey share a closet with the building's fuel-fired water heater for freeze protection

Entrances to a clean-agent or Halon 1301 protected enclosure should have:

• ANo signs, so occupants are not alarmed by the system
• BOnly a sprinkler-riser identification placard
• CSigns directing occupants to hold the abort switch until the fire department arrives
• DWarning signs that the space is protected by a total-flooding agent and that the enclosur…

After a clean-agent discharge, personnel should re-enter the enclosure only when:

• AThe space has been ventilated and it has been determined that the atmosphere is safe
• BThe predischarge horn has stopped, even if agent fog is still visible
• CTen minutes have elapsed, regardless of remaining concentration or combustion products
• DThe abort switch is taped in the operated position

On the MS-14 outline, Halon 1301 systems are treated as which kind of alternative to modern clean agents?

• AA water-based sprinkler alternative governed by NFPA 13
• BA legacy total-flooding gaseous system governed by NFPA 12A, with similar enclosure and a…
• CA portable Class K kitchen alternative governed by NFPA 10 only
• DA low-expansion foam alternative governed by NFPA 11

A sealed total-flooding enclosure measures 20 ft by 25 ft by 10 ft high. If the design concentration is 8 percent by volume, what volume of agent vapor at enclosure conditions is required before leakage and temperature corrections?

• A160 cu ft
• B1,000 cu ft
• C500 cu ft
• D400 cu ft

A clean-agent room has several unclosable openings into adjacent spaces. The correct design response is to:

• AIgnore the openings because clean agents are heavier than air and will stay in the room
• BAdd extra nozzles aimed at each opening and keep the same agent quantity
• CSeal what can be sealed and compensate remaining openings in the quantity and integrity c…
• DDisable the predischarge time delay so the agent dumps before it can leak

A proposed clean-agent design concentration is above NOAEL but below LOAEL. NFPA 2001 treats that space as:

• AAcceptable for unlimited occupancy with no exposure-time limit
• BAllowable for normally occupied use only if personnel exposure can be limited to the stan…
• CProhibited in every case, because any value above NOAEL is treated like a carbon-dioxide…
• DAcceptable only if the abort switch is removed

A door-fan test shows the clean-agent enclosure will not achieve the required hold time. The proper correction is to:

• ASeal cable penetrations, dampers, and other leakage paths, then recalculate or retest hol…
• BLeave the leaks and simply install a second, uncalculated cylinder
• CRemove the predischarge alarm so discharge starts sooner
• DConvert the system to local-application dry chemical using the same pipe

When a technician takes a clean-agent releasing circuit out of service for cylinder work, NFPA 72 releasing-service practice requires that the disconnect:

• ABe unsupervised so the panel does not trouble during the job
• BBe a supervised disconnect that indicates the impairment at the control unit
• CBe accomplished by taping the abort switch in the on position
• DBe accomplished by removing all smoke detectors from their bases

A technician holds the abort switch after the clean-agent cylinders have already begun to discharge. What should be expected?

• AThe cylinder valves will reseat and the remaining agent will be saved
• BThe hold time will be cancelled and HVAC will restart immediately
• CThe system will automatically switch to local-application mode
• DAbort generally cannot stop a discharge that has already started

If the minimum anticipated temperature of a clean-agent enclosure is lowered in the design calculation, the required agent mass generally:

• ADecreases, because cold air needs less agent to reach the same volumetric percentage
• BStays exactly the same, because concentration is independent of temperature
• CIncreases, because colder air is denser and more agent mass is required to produce the sa…
• DDrops to the portable-extinguisher charge listed in NFPA 10

Compared with an NFPA 2001 clean-agent system, an existing NFPA 12A Halon 1301 system is most different because:

• AHalon 1301 is an ozone-depleting agent that must be recovered, and new installations are…
• BHalon 1301 systems never use detection, predischarge alarms, or enclosure integrity
• CHalon 1301 is a wet chemical listed for UL 300 fryers
• DHalon 1301 is stored only as a low-expansion foam concentrate

NFPA 11 (2005) low-expansion foam is foam whose expansion ratio does not exceed:

• A3 to 1
• B20 to 1
• C200 to 1
• D1,000 to 1

In NFPA 11 terminology, foam solution is:

• AFinished foam after it has been aerated at the discharge device
• BPlain water used to flush the proportioner
• CNeat foam concentrate as shipped in the storage tank
• DThe mixture of foam concentrate and water before air is added

A spill of a water-miscible (polar-solvent) flammable liquid should be attacked with:

• AOrdinary protein or AFFF concentrate that is not alcohol-resistant
• BAn alcohol-resistant foam concentrate listed for that fuel
• CHalon 1301 total flooding of the open diked area
• DA portable Class A water extinguisher only

A low-expansion foam system is proportioned at 3 percent. If the foam-solution flow is 200 gpm, the required concentrate flow is:

• A6 gpm
• B3 gpm
• C9 gpm
• D194 gpm

Subsurface foam injection is generally acceptable for which tank fire?

• AA polar-solvent (alcohol) storage tank
• BA commercial kitchen fryer vat
• CAn energized transformer vault with no liquid surface
• DA hydrocarbon (non-water-miscible) product tank listed for subsurface application

Aqueous film-forming foam (AFFF) extinguishes a hydrocarbon spill primarily by:

• ASaponifying animal or vegetable grease into a soapy foam
• BReducing enclosure oxygen to about 12 percent
• CForming an aqueous film that spreads on the fuel and a foam blanket that excludes air
• DFreezing the fuel with discharged carbon-dioxide snow

After a low-expansion foam system has discharged, the contractor should:

• ALeave concentrate in the solution piping so the next fire starts faster
• BFlush concentrate and solution piping and restore the concentrate supply to a ready condi…
• CRefill the tanks with wet-chemical kitchen agent
• DConvert the proportioner to a clean-agent cylinder without a listing change

In foam-application language, a Type II discharge device is one that:

• APlunges foam onto the fuel from a monitor or handline (Type III)
• BDischarges dry chemical simultaneously with the foam
• CInjects foam subsurface through the product for any polar solvent
• DDelivers foam gently onto the liquid surface, as with a foam chamber on a storage tank

A foam system discharges 150 gpm of 3 percent solution for 10 minutes. How many gallons of concentrate are used?

• A15 gallons
• B45 gallons
• C150 gallons
• D450 gallons

Finished-foam quality at the hazard depends most directly on:

• AAccurate proportioning plus air aspiration at the listed discharge device
• BPainting the concentrate tank red
• CUsing any leftover wet-chemical kitchen agent in the foam tank
• DKeeping the foam-water pump at the clean-agent cylinder pressure

Which standard governs pre-engineered wet-chemical extinguishing systems used over commercial cooking appliances?

• ANFPA 17
• BNFPA 17A
• CNFPA 12
• DNFPA 2001

Wet chemical extinguishes a hot cooking-oil fire primarily by:

• AReducing room oxygen to 12 percent
• BSaponifying the grease into a soapy foam blanket that smothers and cools the fuel
• CBlasting the oil out of the vat with a dry-chemical jet
• DFreezing the oil with carbon-dioxide snow

A listed wet-chemical kitchen system must be capable of being actuated:

• AAutomatically only, with no manual pull
• BOnly by the building sprinkler water-flow switch
• CBoth automatically and manually
• DManually only, after employees confirm a fire