Refers to: Ship-owners, Operators, Masters and Managers of PHRS certified vessels

Effective Dates:  26 June 2025

This newsletter provides guidance to suppliers, shipyards, and ship-owners regarding the updated requirements for Material Declarations (MDs) confirming the presence or absence of cybutryne in products supplied for ship construction and maintenance. As of 26 June 2025, the threshold level for cybutryne has been revised to 200 mg/kg, and all declarations must follow the updated IMO-mandated format.

Cybutryne (CAS No. 28159-98-0) was added to the list of controlled substances under the International Convention on the Control of Harmful Anti-Fouling Systems on Ships (AFS Convention). The IMO has mandated that suppliers declare whether cybutryne is present in any product delivered for installation onboard ships.

The latest amendments require the use of the updated material declaration format contained in Appendix 6 of Resolution MEPC.379(80), as amended by MEPC.405(83). This format must be applied to all MDs issued after 26 June 2025. MDs submitted in the outdated format will be considered non-compliant.

Therefore, a new MD in the updated format, reflecting the 200 mg/kg threshold for cybutryne, is required when new coating is supplied after 26 June 2025.

Material Declaration (MD) in accordance with Resolution MEPC.379(80) as amended by MEPC.405(83), shall be required for submission at each International Anti-Fouling System (IAFS) renewal survey and each Inventory of Hazardous Materials (IHM) survey.

PHRS Technical Circular TC 302/25 is relevant, and available via PHRS public access point on https://eapp.phrs.gr/Home/Publications .

Additional information can be found here: