Skip to main content
European Commission logo print header

Low Emission AntiFouling coatings based on the novel discovered post settlement penetration triggered antifouling

Final Report Summary - LEAF (Low Emission AntiFouling coatings based on the novel discovered post settlement penetration triggered antifouling)

Executive Summary:
Marine biofouling, the unwanted growth of marine organisms on the surfaces of boat hulls and other structures submerged into sea water, is a major global problem. If not prevented, it leads to substantially increased fuel consumption and CO2 emissions in the marine transport sector. In addition it can lead to loss of function of protective coatings, in turn decreasing service life and increasing maintenance costs. Marine biofouling also is a vehicle for dissemination of foreign invasive between different ecosystems globally.
Traditional antifouling (AF) technologies are based on coatings that continuously release biocides. The dominating AF solution on the market today is to use copper compounds as the active biocide in coatings that slowly erode with time in water. One alternative AF solution for ships is so called fouling release coatings, which are based on achieving low adhesion between the fouling organisms and the surface, so that the biofouling films detaches when the ship reaches a certain speed. Neither of these two approaches can be regarded as sustainable. Although being efficient, there are serious concerns about the ecological effects of the continuous release of copper into the oceans, whereas the FR coatings have issues with durability and cost.
Low emission antifouling (LEAF) is new innovative concept for AF coatings. The antifouling effect makes use of the behavior of settling barnacles. When barnacles – which are among the most severe biofoulers in many waters- settle on a surface they penetrate into the material. In LEAF the biocide is incorporated and immobilized within the coating which means that the barnacles are exposed to the biocide only after settlement. The antifouling effect is thus not relying on a continuous release biocide and also opens up for the use of non-erodible coatings with potential for long service life. Prior to the start of the project the LEAF concept had been shown to be efficient towards barnacle fouling for a three year period, using ivermectin as the biocide in model polymers.
The aim of the LEAF project has been to further develop and optimize the concept, to demonstrate its industrial feasibility, and to perform a sustainability assessment. RTD activities included: (i) screening and optimization the main biocide and complementary biocides for achieving a more holistic AF efficacy, (ii) screening and optimization of paint ingredients for minimizing biocide emission and maximizing service life, (iii) formulation, characterization and field testing of antifouling paints, (iv) life cycle analysis and assessment of ecotoxicology and human safety aspects, and (v) scale up of prototype paint production and demonstration in boat test.
The project has developed and demonstrated an antifouling paint that shows excellent efficacy and very high user satisfaction in the field, as tested by 55 boat owners in Scandinavia, Mediterranean, and Caribbean waters. Furthermore, the paint is significantly cheaper to produce and has a lower CO2 footprint than current benchmark antifouling paints. Based on the positive results, both in terms of performance in the field, industrial feasibility and sustainability assessment, the project has taken measures to facilitate future product registration according to European regulations, which will be a critical step for introducing the LEAF paint on the market. Dissemination and communication activities have resulted in a high profile and great interest for the project in the scientific, industrial and end-user communities.
In summary, the project has successfully developed and demonstrated a new sustainable marine antifouling coating technology that is now on the verge of becoming an innovative product on the market.

Project Context and Objectives:
Marine biofouling is the unwanted attachment and growth of marine organisms on immersed artificial structures in the marine environment. Colonization of marine biofilms, plants and animals on ship hulls leads to increased fuel consumption,by up to 30% and associated increases in CO2 emissions. Marine biofouling is often also associated with material degradation, via biocorrosion or loss of integrity of protective coatings due to hard fouler penetration. Another consequence is the spreading of alien species transported on ship hulls to different part of the globe, causing permanent harm to local ecosystems. Outside the transport sector, marine biofouling is a significant problem in aquaculture, desalinization plants and power plant cooling systems around the world, where it constricts water flow. Due to its considerable negative effects, marine biofouling is a widespread problem that needs to be prevented by different solutions.
The dominating anti-fouling methods for ship and static marine constructions today is based on using copper compounds as the biocide in an erodible paint formulation. Although efficient, this approach has some drawbacks. Since they rely on a continuous release of copper and paint erosion, it is difficult to achieve coatings with a long service life. In addition, some concerns are starting to be raised regarding the fate and possible ecological effects of copper compounds in the marine environment, especially in isolated water bodies such as enclosed marinas and harbors.
One alternative approach, developed in the past decades, is non-biocide based antifouling techniques working on physico-chemical principles aimed at preventing or minimizing the adhesion of biofoulers by using surfaces with low friction, low surface energy or high hydrophobicity. This in turn can facilitate the release of fouling attached to the surface if the cruising speed reaches a sufficient velocity, hence the term fouling release (FR) coatings. Silicone based coatings are commonly used in the FR approach. They are ecologically inert, but have problems with mechanical strength and long term stability.
The low-emission antifouling concept behind the LEAF project is based on previous research efforts focusing on the barnacle, which is regarded as the most serious biofouling organism in marine waters. Instead of relying on a continuous release of biocides as in conventional antifouling strategies, the LEAF concept makes use of the settling and penetration behavior of barnacles. The biocide is incorporated and immobilized in the coating and only when the barnacles settle and start to penetrate the coating they are exposed to the biocide. Before the start of the LEAF project, proof of the concept had been shown using biocides belonging to the family macrocyclic lactones, which are produced by a soil bacterium living also in the sea sediment.
The main overall goal of the LEAF project has been to develop and demonstrate a novel marine antifouling coating, based on the concept described above and with the following performance criteria:
- Antifouling performance equal or better than currently used technologies on the market
- Lower environmental impact of biocides, by zero or very low emission of biocide
- Increased lifetime and lower maintenance costs, compared to currently used technologies

To reach these criteria, the LEAF project focused on the following goals:
- Selection of biocides for high efficacy against hard foulers
- Selection of paint components to minimize biocide emission and maintain high stability and long service life.
- Optimization of co-biocide addition to achieve efficacy against a broader spectrum of fouling organisms.
- Demonstration of industrial feasibility; scale-up of production of prototype to be used in full scale efficacy test on boats.
- Sustainability assessment, including life cycle analysis, ecological and human safety aspects, in preparation for future registration and exploitation.

Project Results:
Starting from a proof-of-concept, using one specific biocide and model paint, which demonstrated long term efficacy towards barnacle fouling but not other organisms such as bacteria and algae, the LEAF project set out develop, optimize and demonstrate a new type of antifouling coating that could be realistic alternative to the current copper-based coatings that are dominating the market. The work in the project has been divided into five technical work packages, addressing the following:
- Screening and selection of main biocide and co-biocides, development and use of lab assays to test biocide efficacy and toxicity, and testing in the field.
- Selection and testing of paint binders, in order to achieve low biocide emission rates and high stability for longer service life
- Paint formulation development, characterization and testing of adhesion, mechanical properties and release rates in the lab, and panel testing in the field. Field tests were done with several paint + biocide formulations over three seasons at different geographical locations (Sweden, Italy, UK, and Brazil).
- Sustainability assessment, consisting of life cycle analysis including life cycle cost and ecological and human safety aspects. Paints developed in the project were benchmarked against copper-containing paints.
- Demonstration activity, consisting of scale-up of paint production and a boat test during the 2015 boating season.
- Dissemination activities, including publications and conference contributions aimed at the scientific community, and communications in public media and on the internet (website and Facebook page) to reach a wider audience among industry, end-users and other stakeholders.
The main results can be summarized as follows:
- A biocide package, based on abamectin as the main biocide towards barnacles, and zink pyrithione was developed. When formulated in a prototype type paint a good antifouling efficacy was achieved against a wide spectrum of organisms in field tests performed different geographical locations. Laboratory tests showed excellent long term stability and biocide release rates of ~10 ng/cm2/day.
- Sustainability assessment of the prototype yielded a significantly decreased to CO2 footprint as compared to reference paint with copper. Ecological risk scenarios of abamectin as the main biocide identified some data gaps. After filling of these data gaps, the outlook for registering the biocide according to the strict European regulations is encouraging.
- In the demonstration activity 500 litres of prototype paint was produced, and distributed to 55 volunteering boat owners in Scandinavian, Mediterranean and Caribbean waters. The outcome of the demonstration activity, determined by a questionnaire, showed excellent antifouling efficacy and very high user satisfaction.
- Based on the positive results, both in terms of performance in the field, industrial feasibility and sustainability assessment, the project has also taken measures to facilitate future product registration according to European regulation, which will be an critical step for introducing the LEAF paint on the market.
- Via dissemination and communication activities, and judging from feedback received, the project gas gained a high profile and great interest in the scientific, industrial and end-user communities.
In summary, the project has successfully achieved its objectives, and developed and demonstrated a new sustainable marine antifouling coating technology that is now on the verge of becoming an innovative product on the market.
Potential Impact:
The LEAF project aims to develop and demonstrate different copper-free marine antifouling coatings:
- Solvent born rosin based for Do It Yourself use;
- Solvent born rosin based for Professional Use;
- Water born rosin based (use segment to be decided);
- Fouling Release/LEAF where the holistic aspect is given by the physical properties of the matrix and the anti-barnacle from the main biocide already tested in the first period.

In addition, the project will develop new laboratory methods that will be useful in the development of marine antifouling coatings.

Impact for partners
The expected coatings will have significantly lower biocide emission and longer service life than the current state-of-the-art copper-based solutions on the market. The better environmentally profile will give the industrial partners the possibility to place innovative products in the market. In the long term, the low cost, high effectiveness and good environmental profile will lead to innovative products that can challenge the now market leading products based on copper, for the benefit of industry and environment. The sustainability assessment, including life cycle analysis and ecotoxicology and human safety aspects, will compare copper based solutions with the solutions proposed by LEAF, to facilitate the registration of the products in the novel established biocide product regulation in EU. Testing methods developed in the project will be used by the research partners, creating revenues and increasing their competitiveness as collaboration partners and service providers.

Socioeconomic Impacts:
Reduced fuel consumption and CO2 emissions: The antifouling coatings containing biocide (Cu-Oxide) are used today (80% of market) and taking in consideration the difficulties in market penetration by the non-biocide fouling release solution, the Cu-Oxide solutions will be still used in large amount in the near future. The LEAF solution could help in giving both community and policy makers, waiting an ultimate non-biocide solution, the sought efficient alternative. This will mean reduction of fuel consumption and atmospheric emission without accumulate heavy metal in the sediment and in the biosphere.

Longer service life: The LEAF concept permits the use of less erosive coatings and saving both matrix and biocide consumption and they will have a longer service lifetime. This means longer time between dry-dock periods and thus an advantage for the carrier ships and a saving of materials and biocides.

Reduced worker exposure: The possibility to reduce the amount of biocide needed in the paint will reduce the human exposure in the shipyard (professional use) and in the marina (do it yourself). The possibility to achieve a good efficacy even with water born paint containing LEAF biocide package could completely remove the need of solvents and reduce the emission of volatile organic compounds.

EU shipyards vs Asian Shipyards: Especially important economically for the European Shipyards (CESA) the possibility to facilitate the close cabin application of water-born paints when weather conditions in Europe do not permit a rapid solvent evaporation outside and when human exposure to VOC prevents safe indoor work. The efficacy of a waterborne solution could raise the competitiveness of Shipyard in EU compared with the market leading Asian Shipyards.

New methods for research and industry for product development: The method developed in the project will facilitate for other groups to develop future generations of antifouling coatings for the marine transport sector as well as in other fields such as emerging renewable marine energy and fish farming.

List of Websites:
Website address:
Coordinator: Dr Jukka Lausmaa, tel. +46 70 392 4172, mail.
Technical coordinator: Dr Emiliano Pinori, tel. +46 70 527 5613, mail.