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CHEMCO exit exam questions and answers — Set 1

Set 1 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 1 — 30 CHEMCO exit exam questions with answers

1. Which IMO Code regulates the carriage of dangerous chemicals in bulk on chemical tankers?

  • A. IMSBC Code
  • B. IGC Code
  • C. IBC Code
  • D. IMDG Code
Answer: C — IBC Code
The International Bulk Chemical Code (IBC Code) establishes safety standards for design, equipment, and operation of chemical tankers.

2. Under MARPOL Annex II, which pollution category presents the major hazard to human health or marine resources?

  • A. Category Y
  • B. OS (Other Substances)
  • C. Category Z
  • D. Category X
Answer: D — Category X
Category X substances pose the highest risk; discharge into the sea of Category X tank washings is strictly prohibited.

3. What test is performed on tank bulkhead surfaces to detect microscopic hydrocarbon residues before loading sensitive chemical cargoes?

  • A. Hydrostatic pressure test
  • B. Magnetic particle test
  • C. Ultrasonic thickness test
  • D. Wall Wash Test (WWT)
Answer: D — Wall Wash Test (WWT)
Wall Wash Testing uses solvents (methanol/acetone) to check tank cleanliness parameters such as Permanganate Time, Purity, and Chloride content.

4. What type of chemical tanker skin/tank construction is required for carrying high-hazard cargoes like Isocyanates?

  • A. Type 1 chemical tanker
  • B. Single hull barge
  • C. Type 3 chemical tanker
  • D. Open deck vessel
Answer: A — Type 1 chemical tanker
Type 1 chemical tankers afford maximum preventive containment against severe environmental or safety hazards.

5. What material is widely used for cargo tanks carrying aggressive acids such as Nitric or Phosphoric acid?

  • A. Stainless Steel (e.g. 316L, Duplex 2205)
  • B. Aluminum alloy
  • C. Zinc silicate coating
  • D. Mild carbon steel
Answer: A — Stainless Steel (e.g. 316L, Duplex 2205)
Stainless steel offers superior corrosion resistance and versatility for acid and high-purity chemical cargoes.

6. What is the key limitation of Zinc Silicate tank coatings in chemical tankers?

  • A. Highly flammable surface coating
  • B. Incompatible with acids and strong alkalis (pH limits usually 6 to 10)
  • C. Cannot handle aromatic solvents like Benzene
  • D. Melts at room temperature
Answer: B — Incompatible with acids and strong alkalis (pH limits usually 6 to 10)
Zinc silicate reacts with acidic or strongly alkaline solutions, destroying the coating matrix.

7. What document must be maintained on board detailing all chemical cargo loading, discharging, tank washing, and slop handling?

  • A. Radio Log Book
  • B. Cargo Record Book (CRB)
  • C. Bell Book
  • D. Engine Log Book
Answer: B — Cargo Record Book (CRB)
MARPOL Annex II mandates a Cargo Record Book to log every chemical cargo operation and tank wash discharge.

8. What is self-polymerization in chemical cargoes?

  • A. Dissolving of cargo into seawater
  • B. Freezing of liquid into crystal ice
  • C. Evaporation of cargo into atmosphere
  • D. Chemical reaction where monomer molecules join to form long polymers, generating intense heat
Answer: D — Chemical reaction where monomer molecules join to form long polymers, generating intense heat
Cargoes like Styrene monomer or Vinyl Acetate can spontaneously polymerize, producing dangerous heat and pressure building if uninhibited.

9. What mandatory document provides chemical property, health hazard, reactivity, and emergency response data for a chemical cargo?

  • A. Material Safety Data Sheet (MSDS)
  • B. Tonnage Certificate
  • C. Crew List
  • D. Customs Manifest
Answer: A — Material Safety Data Sheet (MSDS)
MSDS (or SDS) provides vital chemical handling data and first-aid instructions before loading any chemical product.

10. What system is used to purge chemical lines and maintain an inert nitrogen cushion over moisture-sensitive cargoes?

  • A. Steam lance system
  • B. Seawater flushing system
  • C. Nitrogen padding / inerting system
  • D. Compressed air blower
Answer: C — Nitrogen padding / inerting system
Nitrogen padding isolates air/moisture reactive cargoes (like Isocyanates) from atmospheric humidity and oxygen.

11. Under STCW Code Table A-V/1-1-3, what is the mandatory requirement regarding regulatory compliance and STCW code requirements during Advanced Chemical Tanker operations?

  • A. Optional adherence based on vessel size
  • B. Strict compliance with approved safety procedures and flag state regulations
  • C. Applicable only during drydock operations
  • D. Verbal recommendation without documentation
Answer: B — Strict compliance with approved safety procedures and flag state regulations
STCW Code Table A-V/1-1-3 mandates strict compliance with approved safety protocols for Advanced Chemical Tanker.

12. What specific safety precaution must be observed when managing regulatory compliance and STCW code requirements for Advanced Chemical Tanker on board?

  • A. Proceeding without informing the officer on watch
  • B. Delegating tasks exclusively to untrained crew members
  • C. Disabling automated safety alarms to save time
  • D. Conducting a thorough risk assessment and briefing all involved personnel prior to starting work
Answer: D — Conducting a thorough risk assessment and briefing all involved personnel prior to starting work
Risk assessments and pre-job briefings ensure all team members understand hazards during Advanced Chemical Tanker operations.

13. What is Threshold Limit Value - Time Weighted Average (TLV-TWA)?

  • A. Safe airborne exposure concentration for normal 8-hour workday and 40-hour workweek
  • B. Maximum limit for 1 minute
  • C. Pressure limit
  • D. Temperature limit
Answer: A — Safe airborne exposure concentration for normal 8-hour workday and 40-hour workweek
TLV-TWA defines the safe average exposure concentration over a standard work shift.

14. What chemical cargo reaction occurs when two incompatible cargoes contact each other?

  • A. Sublimation
  • B. Condensation
  • C. Incompatible chemical reactivity producing toxic fumes, heat, or explosion
  • D. Freezing
Answer: C — Incompatible chemical reactivity producing toxic fumes, heat, or explosion
Incompatible cargoes (e.g. Acids and Caustic Soda) react violently if mixed.

15. What is mandatory prior to personnel entering a chemical cargo tank for inspection?

  • A. Washing with seawater
  • B. Verbal permission from cook
  • C. Tank gas-freeing, atmospheric testing for O2 (20.9%), toxic gas (0 ppm), LEL (0%), and Enclosed Space Entry Permit
  • D. Opening main valve
Answer: C — Tank gas-freeing, atmospheric testing for O2 (20.9%), toxic gas (0 ppm), LEL (0%), and Enclosed Space Entry Permit
Rigorous enclosed space entry safety testing is legally required before tank entry.

16. What personal protective equipment is required during chemical cargo sampling of toxic substances?

  • A. Leather apron
  • B. Chemical suit, boots, face shield/goggles, chemical resistant gloves, and organic vapor mask or SCBA
  • C. Short sleeves
  • D. Standard coveralls
Answer: B — Chemical suit, boots, face shield/goggles, chemical resistant gloves, and organic vapor mask or SCBA
Sampling toxic or corrosive chemicals requires full chemical protective equipment.

17. What equipment must be available near chemical cargo manifolds during transfer operations?

  • A. Steam boiler
  • B. Radio receiver
  • C. Paint spray machine
  • D. Emergency safety shower and eye-wash station
Answer: D — Emergency safety shower and eye-wash station
Safety showers and eyewash stations provide immediate decontamination for accidental spills.

18. What is the P&A Manual on a chemical tanker?

  • A. Pump manual
  • B. Procedures and Arrangements Manual approved by Flag State Administration
  • C. Port anchorage guide
  • D. Personnel manual
Answer: B — Procedures and Arrangements Manual approved by Flag State Administration
The P&A Manual details specific procedures for tank washing, stripping, and slop handling under MARPOL Annex II.

19. What device is installed on chemical tank venting systems to prevent over-pressure or vacuum?

  • A. Check valve
  • B. High-velocity Pressure/Vacuum (P/V) valve
  • C. Globe valve
  • D. Needle valve
Answer: B — High-velocity Pressure/Vacuum (P/V) valve
High-velocity P/V valves vent tank vapors high above deck and protect tanks from pressure damage.

20. What cargo stripping result is required for modern Type 2 chemical tankers built after May 2007 carrying Category X, Y, Z cargoes?

  • A. Maximum residue remaining per tank must not exceed 75 liters
  • B. 1000 liters
  • C. 5 cubic meters
  • D. No limit
Answer: A — Maximum residue remaining per tank must not exceed 75 liters
Under MARPOL Annex II, modern chemical tankers must strip residue down to no more than 75 liters per tank.

21. What is the function of a toxic gas detector tube system (e.g. Dräger tube)?

  • A. Test battery
  • B. Measure oil viscosity
  • C. Measure specific chemical vapor concentrations in ppm by colorimetric reaction
  • D. Measure salinity
Answer: C — Measure specific chemical vapor concentrations in ppm by colorimetric reaction
Indicator tubes measure exact parts-per-million concentrations of specific toxic gases.

22. Why are efficient stripping systems essential on chemical tankers?

  • A. Increase ship speed
  • B. Minimize cargo residue left in tanks prior to mandatory pre-wash or commercial cleaning
  • C. Cool engine room
  • D. Fill ballast tanks
Answer: B — Minimize cargo residue left in tanks prior to mandatory pre-wash or commercial cleaning
Thorough stripping maximizes cargo delivery and minimizes slop washing quantities.

23. Which international regulation specifies the minimum standard for regulatory compliance and STCW code requirements concerning Advanced Chemical Tanker?

  • A. STCW Code Section A-V/1-1-3 and relevant SOLAS/MARPOL conventions
  • B. Port State Control advisory note only
  • C. Tonnage Measurement Convention 1969
  • D. International Load Line Certificate Annex 3
Answer: A — STCW Code Section A-V/1-1-3 and relevant SOLAS/MARPOL conventions
STCW Code Section A-V/1-1-3 sets international standards for training and operational competency in Advanced Chemical Tanker.

24. In the event of an emergency involving regulatory compliance and STCW code requirements during Advanced Chemical Tanker tasks, what immediate action is required?

  • A. Attempt to resolve the incident silently without raising the alarm
  • B. Wait until the end of the watch to log the issue
  • C. Raise the alarm, notify the Officer of the Watch, and execute assigned muster list duties
  • D. Evacuate the vessel immediately without informing the bridge
Answer: C — Raise the alarm, notify the Officer of the Watch, and execute assigned muster list duties
Prompt alarm activation ensures emergency response teams can mobilize immediately.

25. What is the purpose of a mandatory pre-wash under MARPOL Annex II?

  • A. Clean windows
  • B. Polish steel
  • C. Remove high-viscosity or solidifying Category X / Y residues to shore reception
  • D. Wash deck
Answer: C — Remove high-viscosity or solidifying Category X / Y residues to shore reception
Mandatory pre-washes transfer persistent chemical slops to shore reception facilities before departure.

26. What is the Permanganate Time Test used for in chemical tank cleaning?

  • A. Test oxygen concentration
  • B. Test fuel sulfur
  • C. Test water temp
  • D. Detect trace presence of oxidizable organic impurities after cleaning for high-purity alcohol cargoes
Answer: D — Detect trace presence of oxidizable organic impurities after cleaning for high-purity alcohol cargoes
Permanganate time measures how long potassium permanganate retains its pink color in wall wash samples.

27. What code specifies medical emergency response steps for chemical accidents on ships?

  • A. SOLAS Chapter V
  • B. STCW Reg I/9
  • C. MARPOL Annex VI
  • D. Medical First Aid Guide (MFAG)
Answer: D — Medical First Aid Guide (MFAG)
MFAG provides standardized medical response guidelines for chemical spills and exposures.

28. What type of cargo pump is fitted inside individual stainless steel chemical cargo tanks?

  • A. Deepwell centrifugal pump
  • B. Steam duplex pump
  • C. Hand pump
  • D. Gear pump
Answer: A — Deepwell centrifugal pump
Deepwell pumps eliminate cargo pump rooms and isolate individual cargo parcels.

29. Why is water prohibited for cleaning tanks after carrying Concentrated Sulfuric Acid?

  • A. Water freezes
  • B. Water turns steel into wood
  • C. Water reacts exothermically generating extreme heat and corrosive splattering
  • D. Water turns acid into rock
Answer: C — Water reacts exothermically generating extreme heat and corrosive splattering
Adding water to concentrated acid causes violent heat release and severe corrosive boiling.

30. What is a Certificate of Fitness for the Carriage of Dangerous Chemicals in Bulk?

  • A. Crew medical fitness
  • B. Engine overhaul certificate
  • C. Statutory certificate listing all specific chemical products approved for carriage
  • D. Pilot license
Answer: C — Statutory certificate listing all specific chemical products approved for carriage
Certificates of Fitness verify tank coatings, containment types, and allowed chemical lists.

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