Inventory of Hazardous Materials (IHM): Part I surveys, sampling and maintenance

Which ships need an IHM, and which document they carry

Two regimes ask for an inventory, and many ships now answer to both. The EU Ship Recycling Regulation, Regulation (EU) No 1257/2013, applies to ships of 500 GT and above. Since 31 December 2020 existing EU-flag ships have had to carry a verified IHM with an Inventory Certificate, and ships under any other flag have needed IHM Part I with a Statement of Compliance when they call at a port or anchorage in the EU; the same applies in Norway and Iceland. Port state control officers in those ports ask to see it, and a missing or plainly outdated inventory is a finding.

The Hong Kong International Convention for the Safe and Environmentally Sound Recycling of Ships entered into force on 26 June 2025. Ships of 500 GT and above trading internationally under the flag of a party need an International Certificate on Inventory of Hazardous Materials: new ships from delivery, and existing ships by 26 June 2030 or before they go for recycling if that comes first. Where the flag cannot issue the international certificate, a Statement of Compliance is generally used instead, and the class society advises which applies. A ship that already holds an EU certificate still needs the Hong Kong Convention document, usually issued at its next IHM renewal survey on the strength of the existing Part I. Warships, naval auxiliaries and other government ships in non-commercial service fall outside both regimes.

Documents first: building the visual and sampling check plan

For a ship in service, an inventory starts at a desk. The IMO guidelines set out the sequence: collect the information, assess it, prepare a visual and sampling check plan, carry out the check on board, then compile Part I and its location diagram. Skipping straight to the ship produces hundreds of unnecessary samples and still misses equipment nobody thought to look at.

We ask for the general arrangement and fire control plan, machinery and equipment lists, insulation, piping and accommodation specifications, the coating history of the hull and tanks, maker documentation, records of refits and major repairs, and every Material Declaration and Supplier's Declaration of Conformity the ship holds for equipment fitted since delivery. Each item is then placed in one of three groups: shown by documents to contain a listed material, shown by documents not to, or uncertain. The uncertain items become the plan: which ones will be checked visually, which sampled, and which, where sampling is impractical or unsafe, will be recorded as potentially containing hazardous material and treated in the inventory as if they do. Many class societies like to see that plan before the ship visit, and we send it to them through the owner.

Compiling IHM Part I and the location diagram

Part I is ship-specific and follows the standard format in the IMO guidelines, in three parts. Each entry names the item, its location, the listed material, the part of the item that contains it and an approximate quantity, with remarks where an entry rests on a potentially-containing classification rather than on a test result. A location diagram, normally marked up on the general arrangement, shows where each entry is so a repairer or a yard can find it without the original surveyor.

The evidence file goes with Part I: the document assessment, the check plan, sampling records, laboratory certificates and photographs. A surveyor who can trace any line of the inventory back to its evidence verifies faster, and a later buyer or recycling yard can rely on it.

Keeping the IHM up to date after certification

An inventory goes out of date with the first spare part delivered after the survey. Both regimes expect it to be maintained for the life of the ship: the safety management system names who is responsible, and every new item of equipment, spare or batch of paint is checked against the listed materials using the supplier's Material Declaration and Supplier's Declaration of Conformity. Items containing listed materials are added to Part I, items removed are struck out with the date, and each change is logged in the revision history.

The practical difficulty is the declarations themselves: suppliers send them late, send the wrong format or do not send them at all. Our maintenance service takes the purchase records and declarations from the ship or the office, chases what is missing, checks each declaration against the thresholds, updates Part I and the revision log, and flags anything that needs a sample at the next opportunity. Where our technicians are already on board for thickness measurement or NDT, a spot check of the inventory can be added to the same visit.

Parts II and III before recycling, and IHMs in a pre-purchase inspection

At the end of a ship's life, Part I is brought up to date and Parts II and III are added: Part II for operationally generated waste such as sludge, oily residues and cargo residues, and Part III for stores. With the final survey done, the ship receives a ready-for-recycling certificate and must go to a facility authorised under the Hong Kong Convention or, for an EU-flag ship, one on the European List of ship recycling facilities. We can prepare the update and Parts II and III with the crew in the weeks before the final voyage.

For a buyer, the inventory is worth reading during a pre-purchase inspection. A Part I with long lists of potentially-containing entries, no maintenance records since certification, or no cybutryne check points to work and survey findings after delivery, and is better known before the sale is agreed than after.

Frequently asked questions