Question 1

RISQ Q8.17 lists numerous common cargoes (coal, grain products, fishmeal, DRI, metal wastes, sulphatic ores) capable of causing cargo space oxygen depletion, and requires that emergency entry into such a space be by trained personnel with self-contained breathing apparatus under a responsible officer's supervision. Why does this requirement apply even to a cargo space that was recently safely entered for a routine inspection?

Accepted Answer

Oxidation-driven oxygen depletion is a progressive, ongoing chemical process, not a one-time condition — a space that was safe to enter at one point can become oxygen-deficient later in the voyage as the cargo continues to oxidise, so atmosphere cannot be assumed safe based on a previous entry alone This connects directly to the same enclosed-space principle covered elsewhere in this content library (COSWP Ch.15) — atmosphere can deteriorate over time even in a space that was previously tested safe, because the underlying chemical process (oxidation of the cargo) continues throughout the voyage. A cargo hold is not a "tested once, safe forever" space.

Question 2

RISQ Q8.2-8.3 (Solid Bulk Cargo) requires the IMSBC Code's Group A/B/C cargo classification, and a signed certificate of moisture content, Transportable Moisture Limit (TML), and density before loading any cargo that may liquefy. Why is the comparison between actual moisture content and TML the single most safety-critical figure in this whole certificate?

Accepted Answer

A Group A cargo loaded with moisture content above its TML can liquefy under the ship's motion at sea — the cargo effectively becomes a fluid that can shift suddenly to one side, and this shift has caused real bulk carrier capsizes; everything else on the certificate (density, general description) supports planning, but moisture-vs-TML is the line between safe and potentially fatal Liquefaction is a well-documented cause of real bulk carrier losses with crew fatalities — a cargo that looks dry and granular at loading can still contain enough trapped moisture to liquefy once compacted by the ship's motion. This is exactly why RISQ treats the TML certificate as a hard gate (cargo must not be accepted if actual moisture exceeds TML), not as routine paperwork.

Question 3

RISQ's guidance describes the "can test" — half-filling a small container with cargo sample, striking it sharply on a hard surface 25 times, and checking for free moisture — as a method the Master can use at the dockside. What is the correct interpretation of a "dry" result from this test?

Accepted Answer

A dry-appearing result is a useful indicator but does NOT prove the moisture content is below the TML — RISQ's own guidance explicitly warns that material can still exceed the TML even if it remains dry-looking after the can test, so a clear can test is not a substitute for proper laboratory moisture testing This is a deliberately-included trap in the inspection guidance itself: the can test is a useful field check available to anyone onboard, but its limitation is explicit and important — passing it does not guarantee the cargo is actually below TML. Treating a dry can test as definitive proof of safety, rather than as one input alongside the shipper's certificate, is exactly the kind of overconfidence that has contributed to real liquefaction incidents.