Jotun Defends Biocides as Essential Tool in Global Biofouling Push

Date: 14/10/2025
PHOTO: Jotun_HPS2_ISLAND_4K_rev1

As global regulations tighten, Jotun argues that biocidal coatings remain the most effective and environmentally responsible solution for biofouling control.

The international protective coatings supplier Jotun has emphasised the critical role of biocides in preventing biofouling, even as regulatory and environmental scrutiny intensifies. The company argues that antifouling coatings containing biocidal substances remain the most effective solution to reduce marine growth on hulls, improve fuel efficiency, and lower greenhouse gas emissions across the shipping industry.

Shipping has long grappled with the challenge of marine organisms attaching to hulls, increasing drag and reducing efficiency. Today, operators have several options available, but biocidal antifouling coatings remain the industry’s preferred solution. However, in an era increasingly defined by ESG expectations and stringent environmental regulation, questions are being asked about whether these products can align with future sustainability goals.

“Biofouling – the accumulation of marine organisms on the hull of a ship – reduces the efficiency of the vessel causing it to slow down or to use more fuel to maintain operational speed. That is a problem regardless of the owner’s operating strategy. Whether operating directly on the owner’s account, or through charterers, it reduces profitability,” has stated Morten Sten Johansen, Global Category Director, Jotun.

The introduction of IMO regulations such as EEDI for newbuilds in 2013 and EEXI and CII for existing vessels in 2023 has shifted the conversation. Biofouling control is no longer simply a matter of operational efficiency—it is now a compliance requirement linked to emissions reduction targets.

At the same time, the transfer of invasive species via hull fouling has come under the spotlight with both national authorities and the IMO examining how to minimise biodiversity risks. Although only a handful of countries currently enforce biofouling management laws, momentum is building. At MEPC 83 in April 2025, the IMO agreed to begin development of a legally binding framework known as the Biofouling Convention. Work is expected to begin in 2026, though the timeline for implementation may echo other lengthy IMO processes such as the AFS and Ballast Water conventions.

In addition to regulation, some ship operators—particularly those serving consumer-facing sectors like container and car carrier trades—are facing mounting expectations from cargo owners to demonstrate action on emissions and biodiversity protection.

Attitudes within the industry vary, with some owners proactively seeking greener solutions and others focusing on minimum compliance, often constrained by cost considerations. A survey by Jotun found that over 66% of shipowners believe coatings containing biocides are more effective than biocide-free alternatives. Around 20% had no strong view, while only 14% expressed a preference for non-biocidal coatings. According to a 2024 technical evaluation by DNV Maritime Advisory, Jotun-coated vessels collectively avoided 11.1 million tonnes of CO2 emissions in that year alone.

“We firmly believe in taking a holistic view. The best performance is the best for the environment providing that the ingredients comply with relevant local regulations and an environmental risk assessment has been done. Coatings containing biocides are designed to remain effective for periods of up to five years or more for premium priced products and otherwise to give protection at least between dry-dockings,” has commented Petter Andreassen, R&D Chief Chemist in Jotun.

Preventing fouling entirely remains technically challenging. Currently, the most proven method is to apply a biocide-containing coating to the underwater hull. These systems not only deter marine organisms but also protect against corrosion, and can be supported by in-water cleaning where appropriate.

Biocides used in marine coatings also have applications across multiple industries, including agriculture and consumer products. Historically, shipping has used a range of substances—from copper sheathing on wooden vessels to highly toxic compounds—many of which were phased out due to environmental concerns.

The 2008 entry into force of the AFS Convention marked the end of tributyltin (TBT), once described by the IMO as perhaps the most effective antifouling agent ever developed. More recently, in 2023, the IMO also banned cybutryne. Copper compounds subsequently became the predominant active ingredient, used in over 90% of today's fouling protection coatings.

“The issue of biofouling and means to combat its impact is high on the agenda of the IMO and regional and national authorities. Given the IMO’s ambitions around emissions, efficiency and biodiversity, based on current knowledge it is fair to say that the antifouling coating with the best performance is probably the best for the environment providing that the ingredients comply with relevant local laws and regulations, and an environmental risk assessment has been done. Over time, there will no doubt be improvements with coatings manufacturers at the forefront in this regard,” has concluded Andreassen.

Etiqueta: Jotun