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NEBOSH HSE PSM EXAM BRAND
NEW OFFICIAL QUESTIONS WITH
ANSWERS.
Mechanisms of Heat Transfer: - correct answer -Conduction.
Convection.
Radiation.
Typical ignition sources - correct answer -Smoking.
Sparking.
Naked flames.
Electrical discharges.
Hot surfaces.
Mechanical friction.
Lighting.
Zoning/hazardous area classification - correct answer -For
flamable vapors:
Zone 0: A place in which an explosive atmosphere is present
continously.
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Zone 1: A place in which an explosive atmosphere is likely to
occur.
Zone 2: A place in which and explosive atmosphere is not likely to
occur in normal operation.
For flammable dusts: An explosive atmosphere in the form of a
cloud of combustible dust in air: Zone 20, Zone 21, Zone 22.
Conditions for dust to become explosive - correct answer -Particle
size.
Dispersal.
Explosive concentrations. Dust has indicative values like LEL 25-
50 g per cubic meter and UEL ten times the LEL.
Ignition energy.
Heat and humidity.
Dust Explosion Pentagon - correct answer -Oxygen
Heat
Fuel
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Dispersion
Confinement
Hierarchy of actions to prevent dust explosions - correct answer -
Eliminate the Risk.
Use controls to prevent explosions.
Provide controls to mitigate the risk.
Prevention of Dust Explosions - correct answer -Risk
Assessment.
Elimination and reduction of dust as source.
Inerting.
Dust extraction systems.
Good housekeeping.
Avoidance of ignition sources.
NEBOSH HSE PSM EXAM BRAND
NEW OFFICIAL QUESTIONS WITH
ANSWERS.
Mechanisms of Heat Transfer: - correct answer -Conduction.
Convection.
Radiation.
Typical ignition sources - correct answer -Smoking.
Sparking.
Naked flames.
Electrical discharges.
Hot surfaces.
Mechanical friction.
Lighting.
Zoning/hazardous area classification - correct answer -For
flamable vapors:
Zone 0: A place in which an explosive atmosphere is present
continously.
, Page | 2
Zone 1: A place in which an explosive atmosphere is likely to
occur.
Zone 2: A place in which and explosive atmosphere is not likely to
occur in normal operation.
For flammable dusts: An explosive atmosphere in the form of a
cloud of combustible dust in air: Zone 20, Zone 21, Zone 22.
Conditions for dust to become explosive - correct answer -Particle
size.
Dispersal.
Explosive concentrations. Dust has indicative values like LEL 25-
50 g per cubic meter and UEL ten times the LEL.
Ignition energy.
Heat and humidity.
Dust Explosion Pentagon - correct answer -Oxygen
Heat
Fuel
, Page | 3
Dispersion
Confinement
Hierarchy of actions to prevent dust explosions - correct answer -
Eliminate the Risk.
Use controls to prevent explosions.
Provide controls to mitigate the risk.
Prevention of Dust Explosions - correct answer -Risk
Assessment.
Elimination and reduction of dust as source.
Inerting.
Dust extraction systems.
Good housekeeping.
Avoidance of ignition sources.
