The Inventory of Hazardous Materials (IHM) has become one of the most important environmental and compliance frameworks within the maritime industry. Beyond being a regulatory requirement, IHM directly contributes to environmental protection, occupational safety, and safer ship recycling practices across global shipbreaking yards.

At its core, the purpose of IHM is simple: to identify, monitor, and document hazardous materials onboard ships throughout their operational lifetime, ensuring that vessels are eventually recycled in a safe and environmentally responsible manner.

Today, shipowners are increasingly showing serious commitment toward IHM compliance once the overall process and its long-term importance are properly understood. However, the system itself remains technically complex. Continuous maintenance requirements, supplier documentation, changing onboard equipment, and regulatory interpretation often lead to discrepancies and confusion during implementation.

One of the biggest challenges surrounding IHM is the amount of misleading or incomplete information available online. For this reason, it is always better to refer directly to the original regulatory frameworks and official guidance documents rather than relying solely on secondary interpretations.

The primary references for IHM compliance include:

• the International Maritime Organization Hong Kong International Convention for the Safe and Environmentally Sound Recycling of Ships
• the EU Ship Recycling Regulation (EU SRR)
• guidance published by European Maritime Safety Agency
• IMO MEPC.405(83) guidance and associated amendments

These frameworks collectively establish the requirements for preparing, maintaining, verifying, and renewing the Inventory of Hazardous Materials onboard ships.

In practical terms, IHM Part I forms the foundation of the entire inventory system. It identifies hazardous materials contained within the vessel’s structure and equipment during its operational life. The certificate associated with IHM Part I is generally valid for five years and must be renewed accordingly.

Renewal, however, depends heavily on continuous IHM maintenance throughout the certification cycle. If proper maintenance procedures are consistently followed, renewal can often proceed smoothly through verification and document review. On the other hand, poor maintenance practices, missing supplier declarations, or untracked modifications onboard may lead to extensive re-inspections and additional corrective actions.

A useful way to understand this process is to imagine IHM Part I as the major waypoints on a navigational chart. Continuous IHM maintenance then becomes the operational route connecting those waypoints throughout the vessel’s life. Ultimately, the final destination is the ship recycling yard itself.

As the vessel approaches recycling, the inventory process expands further through:

• IHM Part II, covering operationally generated wastes
• IHM Part III, covering stores and consumable items onboard

Together, these final inventories support the vessel’s readiness for safe recycling and help facilitate the issuance of the Ready for Recycling Certificate (RFRC).

In reality, the majority of technical effort during a vessel’s lifecycle is concentrated on maintaining and updating IHM Part I accurately. Because of this complexity, many shipowners increasingly rely on specialized IHM service providers to support:

• document collection
• supplier declaration management
• onboard maintenance procedures
• class and flag administration communication
• certification renewal coordination
• preparation of technical forms and submissions

Professional guidance often helps shipowners avoid unnecessary delays, discrepancies, and non-conformities during audits and renewals.

As a marine professional actively involved in the maritime sector, I also understand that IHM compliance is not only about regulations, but about creating practical and manageable systems for shipowners throughout the vessel’s operational life.

Ultimately, IHM should not be viewed merely as a certification requirement. It represents a lifecycle approach toward environmental responsibility, worker protection, and sustainable ship recycling, all of which are becoming increasingly important within the future of global shipping.