Question 63 RVR03 - Mate of LT 500-1600 GRT

The Correct Answer is D **Explanation for Option D (Correct):** Option D states that "The morpholine cargo must be segregated from the others by at least two barriers." This statement is correct based on chemical compatibility and safety regulations (specifically the IBC Code, Chapter 15, or general chemical handling safety guidance). * **Morpholine** is an organic base (alkaline/caustic). * **Phosphoric acid** is a strong inorganic acid. Bases and acids react violently, producing heat and potentially toxic fumes or spray. Therefore, these two cargoes must be strictly segregated. The IBC Code (International Bulk Chemical Code), which governs tankship transport, mandates that reactive cargoes (like strong acids and strong bases) must be segregated by at least **two intervening barriers** (e.g., two cofferdams, two empty tanks, or a pumproom/void space and an empty tank). Since morpholine and phosphoric acid are incompatible and highly reactive, this segregation requirement is mandatory for safe transport. **Explanation of Why Other Options Are Incorrect:** **A) The minimum protective clothing required for taking samples of phosphoric acid is goggles or a face shield.** This is incorrect. While eye protection is mandatory, phosphoric acid is a corrosive liquid that causes severe skin burns. Sampling requires a much higher level of protection than just goggles/face shield, including full protective gloves, boots, and chemical protective clothing (coveralls or apron) to prevent skin contact, making eye protection alone insufficient. **B) Aluminum, copper, and zinc are prohibited in all valve parts in contact with these cargoes.** This is incorrect, or at least overstated. * Phosphoric acid is corrosive to many metals, including aluminum, zinc, and copper alloys (especially concentrated forms). * Crotonaldehyde and Morpholine have specific material compatibility requirements, but they do not necessarily prohibit *all* three metals simultaneously in *all* valve parts for *all* three cargoes. * For example, stainless steel is generally used for tank components. While copper/zinc (brass/bronze) is often avoided for acid service, aluminum is sometimes acceptable for specific low-concentration services, though generally avoided for high-hazard chemicals in bulk. Stating that *all three* are prohibited in *all* valve parts for *all three* cargoes is too broad and inaccurate, especially since standard stainless steel is often compatible with crotonaldehyde and morpholine. **C) The required warning sign must have the legend "cancer hazard" added to it.** This is incorrect. While exposure to various chemicals requires warning signs, none of the listed cargoes (Crotonaldehyde, Phosphoric acid, Morpholine) are universally classified as known human carcinogens (Category 1A or 1B) under international standards (like GHS, IARC, or NTP) that would mandate the "cancer hazard" warning legend on the required vessel signage. Crotonaldehyde is classified as possibly carcinogenic (Group 3 by IARC), but this does not trigger the mandated "cancer hazard" warning sign requirement for transport documentation and placards.