An Inventory of Hazardous Materials only stays valid if someone owns it. The guidelines anticipate this: the maintenance of the IHM is meant to sit with a named, designated person and be built into the vessel’s management system — not left to whoever happens to remember. In operation, that role often blends into existing hats, so it’s worth being clear about what the role actually involves.
Quick answer
The IHM Designated Person owns the maintenance process after certification: reviewing material changes, collecting supplier evidence, keeping Part I current, tracking certificate dates, and preparing the record for survey or inspection.
What the role is
The IHM Designated Person is the individual responsible for keeping the IHM current and survey-ready throughout the vessel’s operational life. The 2023 IHM Guidelines (IMO resolution MEPC.379(80)) frame IHM maintenance as a managed process — with a procedure, a responsible person, and integration into the vessel’s safety management system — rather than an ad-hoc task.
This is not the same as compiling the original inventory (often done by a surveyor or specialist at the initial survey). It’s about maintaining it afterward: making sure every material change is captured, every supporting document is collected, and the certificate and survey dates are tracked.
A note on language: MANTIS doesn’t certify anything or take on your compliance. The role and the responsibility sit with the vessel’s certified, competent crew. The software is a workspace that makes the role easier to do well.
What the Designated Person actually does
In practice, the responsibilities break down into a handful of recurring duties:
- Review purchases and works for IHM impact. Before (or as) equipment is installed or materials change, decide whether a controlled substance is involved and whether an entry is needed.
- Collect the documentation chain. Obtain Material Declarations and SDoC from suppliers and contractors — ideally as a condition of the work, not after the fact.
- Keep Part I current. Log every material change when it happens; keep the Part I record accurate against the vessel’s real state.
- Keep supporting records organised. SDS files, stores records, and operational waste documents should stay accessible so later recycling preparation does not become a document hunt.
- Track certificates and surveys. Know when the ICIHM / EU certificate expires and when the next survey falls.
- Prepare for surveys and inspections. Assemble the survey pack; close out any previous findings. (See what surveyors check.)
Role checklist
| Responsibility | Practical evidence |
|---|---|
| Change review | Purchases, refits, and replacements checked for IHM impact. |
| Supplier evidence | MD, SDoC, and SDS files requested and attached. |
| Part I upkeep | Current inventory reflects actual onboard state. |
| Dates | Certificate and renewal survey dates tracked. |
| Survey readiness | Exportable pack with record, changes, and evidence. |
How it fits existing vessel roles
Most vessels rarely have a dedicated “IHM officer.” The role typically attaches to someone already on board or ashore:
- The DPA / Designated Person Ashore often holds overall responsibility, fitting IHM into the management system they already run.
- The Chief Engineer is usually closest to the material changes — refits, machinery, refrigerant work — and is the natural day-to-day record-keeper.
- The Captain / Master carries ultimate responsibility for what’s on board and presented at inspection.
What matters is not the title but that the responsibility is explicitly assigned, not assumed. The most common failure mode is diffusion: everyone assumes someone else is keeping the IHM current, and it quietly drifts until a survey exposes the gap.
Making the role sustainable
The role is sustainable when the system does the remembering. A good IHM workspace means the Designated Person doesn’t have to hold certificate dates in their head, chase scattered MDs, or reconstruct a refit’s changes from memory — the change history, the linked documents, and the survey countdown are simply there. That’s the difference between a role that’s a constant background worry and one that’s a few minutes of upkeep per change.
Common role mistakes
- Naming a responsible person but giving them no process or tools.
- Assuming the Chief Engineer, DPA, and office are each handling the same task.
- Collecting evidence but not linking it to the exact Part I change.
- Tracking certificate dates outside the IHM record.
- Treating survey preparation as the first review of the year.
The role works best when the maintenance procedure, evidence ownership, and escalation route are documented clearly.
Related reading:
Give the IHM owner a system that remembers.
MANTIS is IHM compliance software, built so the person responsible for the IHM can keep it current in minutes, not days. Maintained Part I records, MD/SDoC filing, certificate and survey tracking, audit trail, and survey-ready exports.
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