CMC Vessel-Specific Hazards 3

Question 1

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

Accepted Answer

Bulk carriers that have carried grain fumigated with aluminum phosphide

Answer

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.

Question 2

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

Accepted Answer

Both B and C are correct

Answer

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.

Question 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?

Accepted Answer

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

Answer

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

Question 4

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

Accepted Answer

Cargo vapor permeation creating toxic or flammable atmospheres

Answer

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

Question 5

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

Accepted Answer

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

Answer

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.

(CMC) Certified Marine Chemist Practice Test

(CMC) Certified Marine Chemist Practice Test

CMC Vessel-Specific Hazards 3