IHM questions, answered

An IHM is a controlled document listing the hazardous materials built into a vessel, maintained throughout its operational life so they can be managed safely when the ship is recycled. It has three parts: Part I (structure and equipment), Part II (operational wastes) and Part III (stores). How the three parts differ →

Two regulations make it mandatory for vessels of 500 GT and above: the IMO Hong Kong Convention (in force 26 June 2025) and the EU Ship Recycling Regulation 1257/2013. Beyond the legal requirement, a current IHM keeps surveys and port-state inspections straightforward and protects everyone who later works on the vessel.

MANTIS is structured around the Hong Kong International Convention, EU Regulation 1257/2013 on ship recycling, and the 2023 IHM Guidelines (IMO MEPC.379(80), as amended by MEPC.405(83) in 2025), including the Table A and B substance lists. It helps you keep records against those rules — your class society and crew own compliance.

Vessels of 500 GT and above. The EU Ship Recycling Regulation also reaches any-flag vessels of 500 GT+ that call at an EU port or anchorage (Art. 12), so for a yacht in that size class visiting Europe an IHM is effectively unavoidable. Confirm your exact obligations with your flag or class. Does my yacht need one? →

Because the EU SRR applies to any flag of 500 GT and above when you call at an EU port or anchorage (Art. 12) — you carry a flag-issued Statement of Compliance plus Part I of the IHM. Red Ensign (UK) yachts fall under the separate UK SRR and are treated as third-country flag at EU ports.

Scope is set by gross tonnage and where you trade, not by whether the yacht is private or commercial — a 500 GT+ yacht calling at EU ports is in scope either way. Warships and government non-commercial ships are excluded. Your flag administration can confirm any vessel-specific nuance.

The EU SRR onboard-compliance date for existing ships was 31 December 2020 and is already in force. Under the Hong Kong Convention, existing ships need their IHM documentation by their first renewal survey on or after 26 June 2025, fully harmonised with other statutory certificates by 26 June 2030. The 2030 deadline explained →

For new builds, Part I of the IHM is compiled during design and construction and is in place from delivery, drawing on Material Declarations collected from the yard and suppliers. Starting it during the build is far easier than reconstructing it later from incomplete records.

Existing vessels compile Part I retroactively through a hazardous-materials survey — a visual and sampling check, supported by build records where they exist — then maintain it from there. Older yachts with thin documentation can still be brought into line. IHM for older yachts →

Part I lists hazardous materials in the ship's structure and equipment and is maintained throughout the vessel's life. Part II covers operationally generated wastes and Part III covers stores — both are only compiled when a decision to recycle is taken. In service, Part I is the focus.

Table A covers prohibited or restricted substances — such as asbestos, PCBs, ozone-depleting substances and certain anti-foulings. Table B covers materials that must be listed if present above threshold, such as some heavy metals. The full lists and threshold values are set in the IMO IHM Guidelines (MEPC.379(80)). Free IHM handbook →

No — Parts II and III are only compiled when you decide to recycle the vessel. During the operational life, Part I is what you keep current. MANTIS lets you hide Part II and III per vessel if you don't track them, and switch them back on later.

It depends on your flag. EU-flag (and Hong Kong Convention party-flag) vessels carry a ship-specific Inventory Certificate / ICIHM; non-EU, non-party flags carry a flag-issued Statement of Compliance. Each is supplemented by Part I of the IHM (EU SRR Arts. 9 and 12). ICIHM vs Statement of Compliance →

Your flag administration, or a Recognized Organization authorised by it — in practice, your classification society. The surveyor verifies that Part I reflects the actual vessel before the certificate or Statement of Compliance is issued.

Renewal surveys take place at intervals not exceeding five years, in line with the vessel's other statutory certificates. Between renewals you keep Part I current as materials change; the renewal survey checks the inventory still matches the ship. Preparing for the renewal survey →

The surveyor checks that Part I of the IHM reflects the actual vessel — for existing ships, Part I is first established through a hazardous-materials survey (visual inspection plus sampling where a material can't be confirmed by eye). Keeping your records current makes this straightforward.

It varies with the vessel's size, age and how complete the existing documentation is — there's no fixed figure, and a yacht with good build records and a current Part I is quicker than one reconstructed from scratch. Your class society or IHM provider will scope it.

The shipowner, throughout the vessel's operational life — typically by appointing a designated person and building an IHM maintenance procedure into the safety management system. On yachts the designated person is often the shore-based manager or DPA rather than a rotating chief engineer. The designated person's role →

A Material Declaration states a product's hazardous-material content; a Supplier's Declaration of Conformity confirms the MD is accurate. You collect both for in-scope purchases and file them as the evidence behind your Part I entries. Managing MD/SDoC paperwork →

Yes. The MD/SDoC is your evidence that the item is clear, so you collect them for all in-scope purchases regardless of whether hazardous materials are present. Missing declarations are a common gap surveyors ask about.

No — identical replacement parts and coatings are exempt from an IHM update. Non-identical replacements, or anything introducing hazardous materials, do get recorded in the change log and added to Part I. It's still good practice to note the identical replacement for traceability.

A refit installs a lot of material quickly, so the workflow is: require MDs and SDoCs from contractors up front, record each change as it happens, and update Part I for non-identical or hazmat-bearing items. Collecting documentation during the refit is far easier than chasing it afterwards. The refit briefing →

Part I is updated whenever the vessel's particulars change (name, flag, owner, manager) or its hazardous-material situation changes — a hazmat-bearing item installed, removed, or changed in quantity. There's no fixed calendar; it's event-driven, which is why a running change log matters.

According to EMSA guidance, failure to update the IHM is not in itself a detainable Port State Control deficiency — but any inconsistencies must be reported to your administration and rectified at the next survey. Not carrying a required IHM or certificate at all is a more serious matter.

A PSC officer checks that the certificate or Statement of Compliance is valid and that the onboard Part I is consistent with the vessel, sometimes comparing entries against the change log and supporting declarations. A current, well-organised inventory makes the inspection quick. What surveyors check →

That's a matter for your flag administration and Port State Control, and consequences vary by jurisdiction — from findings to be rectified through to more serious enforcement where a required certificate is absent. The practical answer is to keep the IHM current so it never becomes an issue.

It depends on the vessel's size, age and how complete the original build records are, so there's no single figure — your class society or an IHM service provider can quote for establishing and maintaining it. MANTIS itself is free during our beta.

Yes. Part I supports bulk import from Excel using a standard column mapping, which is the quickest route if you're moving from an existing IHM document. Part II and III can be entered manually or imported with assisted onboarding.

When you compose a survey pack, MANTIS lets you pick what to include — Part I inventory, certificate status, change log and more — with your adopted Maintenance Plan as the lead document. It assembles into one PDF from the records you've kept current, ordered the way surveyors expect.

The Maintenance Plan is your governing IHM document. Upload an existing one as a PDF, or generate a vessel-specific manual from your live data. To adopt a version, you confirm your Designated Person has reviewed it; MANTIS records who and when, and locks it. Later material changes flag it for regeneration.

Yes. You can invite people as owner, admin, member, or read-only viewer. Read-only is enforced at the database layer, not just hidden in the interface — so you can safely give a class surveyor or auditor view access with no risk they change anything.

Yes. A per-vessel setting hides Part II (operational waste) or Part III (stores) across the inventory tabs, dashboard and survey pack. Nothing is deleted — it's display-only — so you can switch them back on at any time.

Yes. Fleet plans support multiple vessels under one organisation account with a shared dashboard. Each vessel's data is isolated — crew only see the vessels they're invited to.

Yes — your IHM and account data are stored in the EU (AWS Frankfurt), and our application sub-processors (email, error monitoring, product analytics) are EU-based. The one exception is Microsoft Clarity on our marketing site, which loads only if you consent and is processed by Microsoft in the US under the EU–US Data Privacy Framework. See the Privacy Policy.

MANTIS is free during our beta, so there's no billing to cancel. You can request a full export or deletion of your data at any time from Settings, and we'll confirm when it's done. Our full retention terms are set out in the Privacy Policy.

Not yet. Custom integrations are available on enterprise plans — contact us to discuss your requirements.