Start with the plan’s scope
October 14, 2026 — For a crude-oil tanker, volatile organic compound (VOC) management is a voyage-wide task, not just a loading-port concern. IMO’s summary of MARPOL Annex VI regulation 15.6 says a tanker carrying crude oil must have an approved, ship-specific VOC management plan and effectively implement it. The plan is to address procedures for minimizing emissions during loading, the sea passage and discharge; give consideration to additional VOCs generated by crude oil washing; and identify a person responsible for implementation. The practical test is whether the people carrying out each stage can use the plan’s procedures—not simply whether the document is onboard.
Keep two controls distinct when planning. IMO describes the ship-specific VOC management plan separately from requirements for a vapour emission control system (VECS) that may apply at particular ports or terminals under a Party’s rules. The plan does not, by itself, establish that a particular terminal requires VECS or that a vessel’s equipment meets that requirement. Check the applicable port and terminal arrangements through the relevant operational channels, then coordinate them with the ship’s approved plan. This avoids treating the shipboard emissions plan and shore-side vapour-control arrangements as interchangeable.
Make loading decisions operational
The IMO guidelines make safety the boundary condition for VOC minimization. They recommend that loading procedures account for possible gas release associated with low pressure and, where possible, avoid or minimize excessive throttling and high flow velocity in pipes. They also call for a ship-defined target cargo-tank operating pressure: as high as safely possible, with the aim of maintaining it during loading and carriage of relevant cargo. These are not universal numerical setpoints. The plan should translate the guidance into the vessel’s own approved limits, equipment and procedures rather than inventing a generic target.
Before loading, use the plan as a prompt to confirm the intended tank-pressure target, the relevant transfer configuration and who is responsible for monitoring and responding. If operating conditions require a pressure reduction, the guidelines say the reduction should be as small as possible while maintaining tank pressure as high as possible. They also caution that adding inert gas to raise tank pressure does not prevent VOC release and may increase venting. That makes pressure management a coordinated decision: emissions goals do not override safety, system limits or the vessel’s operating procedures.
Resolution MEPC.185(59): Guidelines for the Development of a VOC Management Plan · MEPC.1/Circ.680: Technical Information on Vapour Pressure Control Systems and Their Operation
Carry the same logic through the voyage
Loading ends, but the plan’s scope does not. Regulation 15.6 calls for procedures covering the sea passage as well as loading and discharge, and the IMO guidelines recommend aiming to maintain the defined target pressure during carriage of relevant cargo. A useful handover is therefore to carry forward the pressure target and any operating instructions that matter to the next watch, rather than treating the loading record as the end of VOC management. The ship’s designated responsible person can help ensure that plan-related tasks remain assigned as watchkeepers and voyage stages change.
If crude oil washing is planned, assess its VOC implications before the operation. The IMO guidelines say the plan should consider the effect of crude oil washing and identify shortening washing duration or using a closed-cycle programme as possible ways to reduce emissions. They also say ship-specific procedures should cover crude oil washing and any VOC-reduction equipment fitted. Treat these as planning considerations, not as permission to change an approved washing programme or disregard the vessel’s safety and cargo-operation requirements.
Volatile organic compounds (VOC) – Regulation 15 · Resolution MEPC.185(59): Guidelines for the Development of a VOC Management Plan · MEPC.1/Circ.680: Technical Information on Vapour Pressure Control Systems and Their Operation
Make implementation verifiable
A practical close-out is to check that the plan covers the ship’s relevant operations, that its stated equipment and procedures match the vessel, and that a responsible person is identified. The guidelines also call for training programmes to facilitate the practices described in the plan. For each voyage stage, operators can use a simple review: What procedure applies? Who carries it out? What condition or decision needs attention? What information must be handed to the next responsible person? This is an implementation aid, not a substitute for the approved plan or shipboard procedures.
The central lesson is that VOC management depends on joining decisions that are often handled in separate phases: transfer routing and tank pressure during loading; pressure management during carriage; crude-oil-washing choices; and the discharge procedure. IMO’s guidance connects all of them while emphasizing safe operation. A useful ship-specific plan therefore gives the crew a continuous operational thread from berth to sea passage and back to discharge—one that assigns responsibility and makes its procedures usable at each handover.
Resolution MEPC.185(59): Guidelines for the Development of a VOC Management Plan · MEPC.1/Circ.680: Technical Information on Vapour Pressure Control Systems and Their Operation