Applicability: shipowners, ship operators, ship managers and ship masters.

As outlined in Class News 04/2022, in 2023 controls on the use of cybutryne as an anti-fouling substance were introduced into the AFS Convention by the International Maritime Organisation (IMO). 

Consequently, the IMO has updated its Guidelines for the Development of the Inventory of Hazardous Materials (IHM), published as Resolution MEPC.379(80). It states that the resolution applies “as soon as possible, or at the latest when the Hong Kong Convention enters into force”. The updated guidelines in the resolution now include cybutryne as a substance to be included in the ship’s IHMs, if present on the ship. 

The European Maritime Safety Agency (EMSA) has also published Guidance on the inclusion of Cybutryne in the Inventory of Hazardous Materials IHM requirements under Regulation (EU) No 1257/2013. 

Suppliers’ Materials Declarations

Suppliers should now ensure that any material declaration (MD) supplied to a shipowner includes confirmation that no cybutryne is present. The MD must follow the format given in Appendix 6 of Resolution MEPC.379(80). 

Requirements for shipowners

For new ships (built on or after 1 January 2023), shipbuilders and shipowners should ensure that any anti-fouling system containing cybutryne is not applied to the ship, as per Resolution MEPC.331(76). See Class News 04/2022 for details

For existing ships, before the next IHM renewal survey, shipowners should record if cybutryne is present in the antifouling system of the ship (i.e. in concentrations on average above 1,000mg per kg of dry paint). This determination should be made based on the information in either the supplied MD, or in the absence of an MD, sampling and testing data. 

Where cybutryne is detected above the required concentration threshold, it should be recorded in the ships’ IHM and actions to ensure compliance with the requirements of the AFS Convention should be taken. 

Where cybutryne has been listed in the IHM and subsequently removed from a ship, in compliance with the AFS Convention, the IHM must also be updated to record its removal.

For further information

Lloyd’s Register’s IHM guidance has been updated to take into account the latest changes and is available on request. 

See also Class News 13/2023 relating to entry into force of the IMO 2009 Hong Kong Convention.

For further information or advice, please get in touch with your local Lloyd's Register office or contact

Download PDF of Class News 11/24