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CHEMCO exit exam questions and answers — Set 2

Set 2 of the Advanced Training for Chemical Tanker Cargo Operations (CHEMCO) exit exam bank — 30 of 377 questions, with the correct option marked and a one-line explanation for every one. Read it end to end, jump to a single set, or search it — then sit the same bank as a timed paper. The real DG Shipping exit exam is 30 marks with 15 to pass.

These are the bank's original groupings. Practising deals the whole bank out again every time you reshuffle, so a practice “Set 3” is a different 30 questions each time — the set numbers below are the source file's, and are only used here so the key stays navigable. Options are listed in their original order with fixed letters; when you practise, those move too.

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Set 2 — 30 CHEMCO exit exam questions with answers

1. What is the function of inert gas on chemical tankers carrying cargoes with flashpoints below 60°C?

  • A. Change color
  • B. Dissolve fumes
  • C. Maintain oxygen concentration below 8% to prevent flammability
  • D. Heat cargo
Answer: C — Maintain oxygen concentration below 8% to prevent flammability
Inerting reduces oxygen below 8%, eliminating explosion hazards in flammable chemical tanks.

2. What hazard is associated with Benzene cargo exposure?

  • A. Turns skin blue
  • B. Known human carcinogen causing leukemia and bone marrow damage
  • C. Heavy metal poisoning
  • D. Non-toxic
Answer: B — Known human carcinogen causing leukemia and bone marrow damage
Benzene is a aromatic hydrocarbon with severe chronic carcinogenic toxicity.

3. What is closed gauging on a chemical tanker?

  • A. Opening tank lids
  • B. Measuring by draft
  • C. Eye sight measuring
  • D. Measuring cargo level using vapor-tight devices without releasing toxic vapors
Answer: D — Measuring cargo level using vapor-tight devices without releasing toxic vapors
Closed gauging prevents crew exposure to toxic chemical fumes during level checks.

4. What chemical condition causes Phenol to solidify at temperatures below 40°C?

  • A. Nitrogen reaction
  • B. High melting point (~41°C) requiring continuous heating during transit
  • C. High water content
  • D. Evaporation
Answer: B — High melting point (~41°C) requiring continuous heating during transit
Phenol freezes at ~41°C; heating systems keep it liquid above 50°C.

5. How frequently must operational drills and practical checks for regulatory compliance and STCW code requirements be conducted for Advanced Chemical Tanker?

  • A. Once every 5 years during special survey
  • B. Only when requested by port State control inspectors
  • C. At least monthly or as mandated by SOLAS and shipboard safety management system (SMS)
  • D. Annually prior to vessel drydocking
Answer: C — At least monthly or as mandated by SOLAS and shipboard safety management system (SMS)
Regular drills maintain crew emergency readiness and satisfy SOLAS requirements.

6. What documented record must be maintained on board following completion of tasks related to regulatory compliance and STCW code requirements in Advanced Chemical Tanker?

  • A. Entry in the official Deck or Engine Logbook recording date, time, and operational parameters
  • B. No written record is required
  • C. Verbal update to port agent without logging
  • D. Unsigned note on the shipboard notice board
Answer: A — Entry in the official Deck or Engine Logbook recording date, time, and operational parameters
Official logbook entries provide mandatory legal documentation of shipboard safety tasks.

7. What chemical cargo property is defined as the lowest temperature at which liquid emits flammable vapor?

  • A. Flashpoint
  • B. Auto-ignition temp
  • C. Pour point
  • D. Boiling point
Answer: A — Flashpoint
Flashpoint determines cargo flammability classification under SOLAS and IBC rules.

8. What is the function of a toxic vapor return line during chemical loading?

  • A. Return displaced toxic/flammable tank vapors to shore treatment plant
  • B. Supply fresh water
  • C. Return liquid cargo
  • D. Equalize electric grounds
Answer: A — Return displaced toxic/flammable tank vapors to shore treatment plant
Vapor return lines route displaced vapors to shore recovery systems.

9. What is the role of an Inhibitor Certificate for chemical cargoes prone to polymerization?

  • A. Certifies engine power
  • B. Waives safety checks
  • C. Authorizes high speed
  • D. Certifies inhibitor name, concentration, date added, duration of effectiveness, and temp limits
Answer: D — Certifies inhibitor name, concentration, date added, duration of effectiveness, and temp limits
Shippers must provide inhibitor certificates verifying cargo stability during sea transit.

10. What type of personal protective suit provides complete gas-tight isolation against fatal chemical atmospheres?

  • A. Raincoat
  • B. Leather jacket
  • C. Gas-tight Type 1 (Level A) chemical suit with internal SCBA
  • D. Cotton boiler suit
Answer: C — Gas-tight Type 1 (Level A) chemical suit with internal SCBA
Level A gas-tight suits provide complete isolation against severe toxic chemical gases.

11. What is the maximum allowed discharge rate of Category Y cargo residues under MARPOL Annex II outside Special Areas?

  • A. Direct at jetty
  • B. Ship speed min 7 knots, below waterline discharge, distance > 12 nm from coast, water depth > 25 m
  • C. Any speed in port
  • D. 100 knots
Answer: B — Ship speed min 7 knots, below waterline discharge, distance > 12 nm from coast, water depth > 25 m
MARPOL Annex II specifies strict en-route discharge requirements for chemical tank washings.

12. What material coating is ruined if cleaned using high-pressure hot water above 60°C containing alkaline soaps?

  • A. Teak wood deck
  • B. Stainless steel
  • C. Epoxy tank coatings
  • D. Copper piping
Answer: C — Epoxy tank coatings
Hot water and strong alkalis cause blistering and degradation of epoxy linings.

13. What is the function of a cargo tank cofferdam on a chemical tanker?

  • A. Stores drinking water
  • B. Collects rainwater
  • C. Isolates chemical cargo tanks from accommodation, machinery spaces, or incompatible liquid tanks
  • D. Holds spare engine pistons
Answer: C — Isolates chemical cargo tanks from accommodation, machinery spaces, or incompatible liquid tanks
Cofferdams provide isolating void spaces preventing dangerous chemical cross-contamination.

14. What instrument measures relative humidity and dew point inside cargo tanks before loading moisture-sensitive chemicals?

  • A. Barometer
  • B. Chronometer
  • C. Anemometer
  • D. Electronic Hygrometer / Dew point meter
Answer: D — Electronic Hygrometer / Dew point meter
Hygrometers verify tank dryness before loading water-reactive chemical cargoes.

15. What action should be taken if Caustic Soda splashes into a seafarer's eye?

  • A. Immediately flush eye with clean fresh water at eyewash station for at least 15-20 minutes
  • B. Rub eye with rag
  • C. Apply engine oil
  • D. Close eye until tomorrow
Answer: A — Immediately flush eye with clean fresh water at eyewash station for at least 15-20 minutes
Immediate continuous water flushing prevents severe chemical alkali eye burns.

16. What is the function of high level and overfill alarms on chemical cargo tanks?

  • A. Provide audible/visual warnings at 95% and 98% capacity to prevent overflow
  • B. Measure ship roll
  • C. Signal pump room light
  • D. Indicate empty tank
Answer: A — Provide audible/visual warnings at 95% and 98% capacity to prevent overflow
High level (95%) and overfill (98%) alarms warn watchkeepers to prevent cargo overflows.

17. What type of personal protective equipment (PPE) is essential when handling regulatory compliance and STCW code requirements under Advanced Chemical Tanker guidelines?

  • A. High-visibility vest only
  • B. Basic cotton coveralls without eye or foot protection
  • C. Certified task-specific PPE meeting SOLAS/IMO performance standards
  • D. Standard street clothing with rubber gloves
Answer: C — Certified task-specific PPE meeting SOLAS/IMO performance standards
Approved PPE protects personnel against specific physical and chemical hazards.

18. What parameter must be verified prior to authorizing enclosed space entry for regulatory compliance and STCW code requirements related to Advanced Chemical Tanker?

  • A. Oxygen level at 15% with ventilation turned off
  • B. Temperature check only
  • C. Visual inspection through access hatch without gas testing
  • D. Atmospheric oxygen level at 20.9% and zero toxic/flammable gas concentration
Answer: D — Atmospheric oxygen level at 20.9% and zero toxic/flammable gas concentration
Enclosed space safety requires verified atmospheric gas testing prior to entry.

19. What is the primary danger of Nitrogen gas used for inerting chemical tanks?

  • A. Flammable explosion
  • B. Green skin
  • C. Acid burns
  • D. Oxygen displacement causing rapid asphyxiation and unconsciousness without warning
Answer: D — Oxygen displacement causing rapid asphyxiation and unconsciousness without warning
Nitrogen displaces air quietly, causing instant fatal oxygen deficiency.

20. What chemical cargo term describes liquids that produce severe lung damage if vapors are inhaled?

  • A. Respiratory toxic / Pulmonary edema hazard
  • B. Mineral water
  • C. Viscous liquid
  • D. Sweet scent
Answer: A — Respiratory toxic / Pulmonary edema hazard
Vapors of chemicals like Phosgene or Nitric acid cause fatal lung fluid accumulation.

21. What type of sampling equipment is used when taking chemical samples without opening tank hatches?

  • A. Closed-loop vapor lock sampling valve with portable sampling bottle
  • B. Open bucket
  • C. Glass cup
  • D. Soup ladle
Answer: A — Closed-loop vapor lock sampling valve with portable sampling bottle
Vapor locks allow sealed sampling without exposing crew to toxic vapors.

22. What document lists compatibility restrictions when planning stowage of multiple chemical cargoes?

  • A. Engine manual
  • B. Suez pass
  • C. Load line certificate
  • D. USCG Chemical Compatibility Chart / IBC Code Matrix
Answer: D — USCG Chemical Compatibility Chart / IBC Code Matrix
Compatibility matrices prevent stowage of reactive chemical pairs in adjacent tanks.

23. What is the function of a tank washing machine on chemical tankers?

  • A. Sandblasting
  • B. Paint spraying
  • C. High-pressure rotary water jets to wash chemical residues off bulkheads
  • D. Bilge pumping
Answer: C — High-pressure rotary water jets to wash chemical residues off bulkheads
Rotary tank washing machines clean internal bulkhead surfaces thoroughly.

24. Why must cargo pumps and pipelines be thoroughly blown down with air/N2 after cargo discharge?

  • A. Increase pressure
  • B. Cool main engine
  • C. Clear liquid pockets from piping to prevent contamination and line freezing
  • D. Clean hull
Answer: C — Clear liquid pockets from piping to prevent contamination and line freezing
Line blowing empties piping systems completely, leaving lines clean and dry.

25. What is Short Term Exposure Limit (STEL)?

  • A. 1 year limit
  • B. 24 hour limit
  • C. Ignition temp
  • D. Maximum allowable concentration for continuous 15-minute exposure period
Answer: D — Maximum allowable concentration for continuous 15-minute exposure period
STEL defines the safe peak exposure concentration allowed over 15 minutes.

26. What system prevents static electricity accumulation during high-rate loading of non-conducting chemical solvents?

  • A. Max speed pumping
  • B. Spraying water
  • C. Restricting initial loading rate (flow velocity < 1 m/s) and grounding/bonding lines
  • D. Opening hatches
Answer: C — Restricting initial loading rate (flow velocity < 1 m/s) and grounding/bonding lines
Flow velocities under 1 m/s prevent static spark accumulation during initial loading.

27. What step is taken if a chemical cargo tank lining shows extensive breakdown and rust spots?

  • A. Fill with seawater
  • B. Paint household paint
  • C. Tank must be de-gassed, cleaned, grit-blasted, and re-coated before loading compatible cargo
  • D. Ignore rust
Answer: C — Tank must be de-gassed, cleaned, grit-blasted, and re-coated before loading compatible cargo
Damaged tank coatings contaminate cargoes and lead to rapid hull steel corrosion.

28. Who is responsible for supervising all chemical cargo operations and safety checks on board?

  • A. Chief Cook
  • B. Steward
  • C. Chief Officer / Designated Cargo Officer
  • D. Deck Cadet
Answer: C — Chief Officer / Designated Cargo Officer
The Chief Officer leads cargo operations and dangerous chemical safety compliance.

29. What key responsibility belongs to seafarers performing watchkeeping duties for regulatory compliance and STCW code requirements under Advanced Chemical Tanker?

  • A. Bypassing safety trips during routine operations
  • B. Leaving watchkeeping station unattended
  • C. Continuous monitoring of operational parameters and immediate reporting of anomalies
  • D. Operating equipment beyond design pressure limits
Answer: C — Continuous monitoring of operational parameters and immediate reporting of anomalies
Continuous vigilance and prompt communication are core watchkeeping duties under STCW.

30. Which document contains detailed hazard data and emergency handling instructions for substances involved in regulatory compliance and STCW code requirements during Advanced Chemical Tanker?

  • A. Crew List document
  • B. Ship's Cargo Manifest summary page
  • C. Safety Data Sheet (SDS) / Material Safety Data Sheet (MSDS)
  • D. Bill of Lading description
Answer: C — Safety Data Sheet (SDS) / Material Safety Data Sheet (MSDS)
Safety Data Sheets provide critical hazard identification, PPE requirements, and first aid response steps.

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