Chemical Hazard & Risk Management 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.
Read the first 7 Chemical Hazard & Risk Management flashcards as text
Under NFPA 306, which condition requires a Marine Chemist certificate before hot work can begin on a vessel?
Answer: Vessels in repair yards, shipyards, or where hot work could create fire or explosion hazard in spaces containing flammable vapors
NFPA 306 requires a Marine Chemist certificate for hot work on vessels where fire or explosion hazards exist due to flammable vapors, particularly in shipyard and repair environments.
When assessing risk from a spilled corrosive liquid in a bilge space, which hazard interaction is of greatest concern to a Marine Chemist?
Answer: The corrosive reacting with structural steel to generate hydrogen gas
Strong acids reacting with iron or steel liberate hydrogen gas, which can accumulate to explosive concentrations in confined bilge spaces.
A Marine Chemist is evaluating inhalation risk from a chemical with a vapor pressure of 200 mmHg at 25°C and a TLV-TWA of 0.1 ppm. What does the high vapor pressure indicate?
Answer: The chemical can generate airborne concentrations far exceeding its TLV, indicating high inhalation risk
A high vapor pressure means the substance readily forms vapors that can reach concentrations many orders of magnitude above a very low TLV, making inhalation a primary concern.
Which OSHA standard specifically governs permit-required confined space entry on general industry vessels and shipyard employment?
Answer: 29 CFR 1910.146 and 29 CFR 1915.12
29 CFR 1910.146 covers permit-required confined spaces in general industry, while 29 CFR 1915.12 specifically addresses confined and enclosed spaces in shipyard employment.
The concept of 'hierarchy of controls' when managing chemical hazards aboard a vessel places which control method at the highest priority?
Answer: Elimination or substitution of the hazardous chemical
The hierarchy of controls prioritizes elimination first, followed by substitution, then engineering controls, administrative controls, and finally PPE as the last resort.
A Marine Chemist performing a pre-entry test detects 15% LEL in a space classified as requiring a 'Safe for Hot Work' certificate. What is the correct course of action?
Answer: Deny the certificate; LEL must be 0% for hot work authorization
A 'Safe for Hot Work' certificate requires 0% LEL; any detectable flammable vapor concentration disqualifies the space from hot work authorization.
Which chemical property best predicts whether a liquid cargo will accumulate as vapor in the lowest point of a hull space?
Answer: Vapor density relative to air
Vapor density determines whether a chemical vapor sinks (>1 relative to air) and accumulates in low-lying areas such as bilges and double bottoms.