By Capt. Neeraj Bharti, Founder, Master Mariner · Published · 2 min read
IMO biofouling rules are becoming binding: what changes for owners and contractors
For most of the last decade, biofouling management was voluntary at IMO level. Ships were encouraged to have a plan and keep records, and individual countries set their own arrival rules. That is changing. IMO has been working towards a mandatory framework, and the standards around in-water cleaning have been filling in. This article sets out where things stand and what owners and contractors should prepare for. It will be updated as decisions are made.
What exists now
The 2023 Biofouling Guidelines (MEPC.378(80)). These replaced the 2011 guidelines and set out how ships should manage biofouling: a biofouling management plan, a record book, risk assessment, inspection, a fouling rating scale, and guidance on cleaning.
Guidance on in-water cleaning (MEPC.1/Circ.918). This links in-water cleaning methods to the fouling rating, distinguishing between proactive cleaning of microfouling and reactive cleaning of macrofouling, and points towards capture of debris for macrofouling.
Industry and ISO standards. BIMCO and ICS publish an industry standard for in-water cleaning with capture and an approval procedure for cleaning companies. ISO has published standards on testing in-water cleaning systems, and further ISO work on hull cleaning has been published or is in development.
National rules. Australia, New Zealand, Brazil and others apply their own requirements on arrival. See clean hull on arrival.
Where IMO is heading
IMO's Marine Environment Protection Committee has agreed to develop a legally binding framework for biofouling management, building on the 2023 Guidelines. The detail, including scope, timing and how compliance will be shown, is being worked out through IMO's sub-committees. Until it is adopted, the Guidelines remain the reference, but owners should assume that what is voluntary today will become mandatory.
What it is likely to mean for owners
- Plans and records will matter more. A biofouling management plan and an up-to-date record book will move from good practice to requirement.
- Evidence of cleaning will need to be specific: date, location, method, areas, condition before and after.
- Cleaning method will be tied to fouling level, with capture expected for macrofouling.
- Contractor approval may become a factor in which companies ports allow to clean.
What it is likely to mean for contractors
- Method transparency: whether cleaning is with or without capture, and how coating is protected
- Approval and testing against recognised standards
- Reporting that fits the ship's biofouling record book
How to prepare now
- Make sure the ship's biofouling management plan reflects the 2023 Guidelines.
- Keep the record book current, with every inspection and cleaning entered.
- Ask contractors for reports that state method, capture, areas and condition.
- Plan cleaning against fouling rating triggers, not only when performance drops.
See capture or no capture, the complete guide to ship hull cleaning, and our underwater hull cleaning service.
Sources & further reading
Frequently asked questions
Are IMO biofouling rules mandatory?
Not yet. The 2023 Biofouling Guidelines are voluntary, but IMO has agreed to develop a legally binding framework building on them. Several countries already enforce their own arrival rules.
What are the 2023 IMO Biofouling Guidelines?
Resolution MEPC.378(80), which sets out biofouling management for ships: a management plan, record book, risk assessment, inspection, a fouling rating scale and guidance on cleaning.
What is MEPC.1/Circ.918?
IMO guidance on in-water cleaning of ships' biofouling, which links cleaning methods to the fouling rating and points towards capture of debris when macrofouling is removed.
How should owners prepare for mandatory biofouling rules?
Keep the biofouling management plan and record book up to date, ask contractors for detailed reports, and plan cleaning against fouling rating triggers.
- IMO biofouling regulation
- MEPC biofouling
- biofouling guidelines 2023
- in-water cleaning standard
- biofouling mandatory framework
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