Spillage of methanol during cargo operations

A member has reported an incident in which the valve on a cargo tank was damaged, causing a leak of approximately 1000 litres of methanol. The incident occurred during cargo operations; an FPSO crane operator was lowering an empty methanol tank onto the deck of a support vessel. On lowering, the empty tank struck another full tank of methanol already on deck, causing damage to a valve, which caused the spill.

The Master of the support vessel immediately instructed the FPSO to remove the leaking tank and it was rigged for hoisting by the FPSO crane. Despite this request, the crane operator failed to lift off the leaking container and simply lowered it back to the deck. The crew of the support vessel responded immediately by deploying fire hoses and continuously dousing the deck area and leaking container, to disperse the spilt cargo.

Our member noted the following:

• The crane operator on the FPSO failed to follow instructions given by the deck crew and Master at a critical moment;
• Existing procedures were not properly followed:
  • The support vessel’s DGC (Dangerous Goods Certificate) did not allow for methanol cargo to be carried; this was not reviewed by vessel staff prior to cargo operations
  • There had not been a full review of the cargo-s MSDS (Material Safety Data Sheet) before operations started;
  • Had the officers on the support vessel correctly reviewed the necessary documents, they would have been able to pro-actively exercise the stop work policy and prevent this incident from occurring.

Our member’s crew took the following actions:

• Immediate request for assistance from Master to FPSO to remove the leaking container;
• Following aborted cargo lift, Master immediately departed the Safety Zone to safe distance;
• Immediate and effective action from deck crew to flush the deck with water, douse the tank and subsequently also flush the tank out until all traces of methanol had dispersed.

Key lessons learnt:

• Dangerous Goods Certificates and Material Safety Data Sheets should be reviewed on-board before starting cargo operations, to ensure that full compliance is assured at all times. In case of doubt, Masters should check with appropriate company authority ashore;
• In this case despite the identified failings and high potential to become a serious incident, the entire crew responded swiftly and effectively to prevent the incident escalating, highlighting the importance of good drills, exercises and emergency response awareness.

Members may wish to refer to the following incidents (search words: cargo, spill, leak, container)

• Incorrect lifting equipment used (leading to spillage of 45l of ethylene glycol)
• ‘Routine’ task, non-routine result: Batteries stored sideways leak battery acid