Practice Test Geeks(CMC) Certified Marine Chemist Practice Test
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Vessel-Specific Hazards Flashcards

7 cards from real CMC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. Which type of vessel cargo space requires testing for phosphine (PH3) as a primary concern during the marine chemist's inspection?

    Answer: Bulk carriers that have carried grain fumigated with aluminum phosphide

    Aluminum phosphide is commonly used to fumigate grain shipments and reacts with moisture to produce toxic phosphine gas, which can persist in cargo holds and surrounding spaces.

  2. On an inert gas-protected tanker, a marine chemist must enter the inert gas deck seal compartment. What is the primary atmospheric hazard?

    Answer: Both B and C are correct

    Inert gas system spaces can contain oxygen-deficient atmospheres from both the inert gas itself (CO2/N2/flue gas) and may also contain carbon monoxide when flue gas is the inertant source.

  3. A marine chemist finds a tank certified as 'Safe for Hot Work' but later determines the adjacent fuel oil double-bottom was not tested. Under NFPA 306, what must occur?

    Answer: The certificate must be revoked and adjacent spaces must be tested and certified

    NFPA 306 requires that all spaces adjacent to an area where hot work will be performed must be tested and included in the certification.

  4. What is the specific hazard associated with the void spaces between the cargo tanks and hull of a chemical tanker?

    Answer: Cargo vapor permeation creating toxic or flammable atmospheres

    Cargo vapors from chemical cargoes can permeate through tank walls into interbarrier or void spaces, creating hazardous atmospheres requiring testing before entry.

  5. During gas freeing of a crude oil tanker, when is it MOST dangerous for personnel to be on deck near tank openings?

    Answer: When the tank atmosphere passes through the flammable range (LEL to UEL) during purging

    As the tank atmosphere passes through the explosive range during gas freeing, ignition of escaping vapors could occur from static discharge, sparks, or other ignition sources near the openings.

  6. A cargo tank on a product tanker previously carried tetraethyl lead (TEL) blended gasoline. What special precaution applies to the marine chemist's inspection beyond standard hydrocarbon testing?

    Answer: Requiring supplied-air equipment regardless of hydrocarbon readings due to lead contamination

    Tetraethyl lead is an extremely toxic organolead compound that can persist as residue in tanks; supplied-air breathing apparatus is required for any entry into tanks that have carried TEL-blended fuels.

  7. What condition defines an 'oxygen-enriched atmosphere' hazard in a vessel space according to OSHA standards?

    Answer: Oxygen concentration above 22%

    OSHA defines an oxygen-enriched atmosphere as one containing more than 22% oxygen by volume, which significantly increases fire and explosion risk.