Hengstmann et al. Environmental Sciences Europe (2026) 38:20 
The European Union (EU) pursues the expansion of 
renewable energies, including offshore wind energy, 
to accomplish the energy transition and become inde- 
pendent from energy suppliers and fossil fuel-delivering 
countries outside Europe [15, 20]. In 2024, the installed 
offshore wind capacity in the EU was already 21 gigawatt 
(GW), with Denmark having the highest share of offshore 
wind energy in their energy mix (26%) and Germany 
having the highest installed capacity (9,100 GW) [42]. 
According to the Ostend Declaration of Energy Minis- 
ters in April 2023, the objective is to increase the capac- 
ity of offshore wind energy in North Seas to 120 GW and 
at least 300 GW installed by 2030 and 2050, respectively 
‚33]. Accordingly, countries bordering the North Sea aim 
to revise their energy transition targets and expansion of 
offshore wind capacity. 
The rapid extension of offshore wind farms (OWFs) 
requires a suite of key aspects to be evaluated and 
approved by each country’s authorities prior to operation. 
This covers the planning, licensing and construction, but 
also operational and decommissioning processes. For 
these processes, also environmental aspects have been 
integrated into administrative and regulatory procedures. 
For example, specific areas have been designated for off- 
shore wind energy expansion in national marine spatial 
and/or site development plans, and strategic environ- 
mental assessments have been carried out (e.g. [4, 6, 27, 
39]). 
Scientific research on chemicals introduced into the 
marine environment by OWFs has only recently begun 
and only few studies are available, especially focusing on 
metal release from galvanic anodes used for corrosion 
protection and laboratory studies on leachates from coat- 
ings (e.g. [3, 11, 12, 44]). Therefore, information on pos- 
sible sources and types of chemicals applied at OWFs is 
scarce and was only recently reviewed [21]. Additionally, 
ecotoxicological data for the emitted chemicals are often 
missing. While some compounds are listed as chemicals 
of concern and are at least under observation, for numer- 
ous chemicals, risk assessments for the marine environ- 
ment are lacking [21]. 
In the EU, the Marine Strategy Framework Directive 
(MSFD) and the Water Framework Directive (WFD) aim 
to achieve a good environmental and chemical status of 
the marine and coastal environments and address pollu- 
tion by chemical contaminants in the seas in general, but 
not specifically for OWFs or other potential contaminant 
sources. According to the MSFD (Descriptor 8), concen- 
trations of pollutants at sea are supposed to be at levels 
that do not result in any pollution effects [16]. Further, 
the EU zero-pollution action plan aims to increase envi- 
ronmental protection from hazardous chemicals and 
reduce, for instance, specifically microplastic pollution 
Page 2 nf 9 
by 30% by 2030 [14]. With respect to chemical emissions 
from OWFs, there is no directive in place at EU level. 
The Convention for the Protection of the Marine Envi- 
ronment of the North-East Atlantic (OSPAR) gives first 
recommendations with respect to environmental impacts 
of OWFs, like noise effects, input of waste and chemi- 
cal pollutants and impacts on habitats and fauna [30]. 
However, at the moment, implementing regulations is the 
responsibility of each country. 
Differences and gaps in regulations on chemical emis- 
sions from OWFs on a European or national level can 
lead to insufficient protection of the marine environment. 
Building upon the scientific review by Hengstmann et al. 
21], that summarizes the state of research for chemical 
emissions from OWFs, this policy brief focuses on the 
regional structure of regulatory frameworks and provides 
policy-related recommendations. Therefore, this policy 
brief addresses regulations on chemical emissions from 
OWFs in North Sea bordering countries in the European 
Economic Area (EEA) with the objective to (i) give an 
overview of existing national regulatory approaches, (ii) 
identify differences between countries and overall gaps 
and (iii) recommend next steps for the further develop- 
ment of regulations on chemical emissions from OWFs. 
Thereby, the policy brief aims to increase the protection 
of the environment and facilitate licensing procedures. 
Methods 
Zxisting regulations for chemical emissions from OWFs 
were compared for a selection of EEA states bordering 
the North Sea, namely Belgium, Denmark, France, Ger- 
many, the Netherlands, and Norway. An overview of 
OWFs in the respective countries is, for example, pro- 
vided by OSPAR Data & Information Management Sys- 
tem [32]. An online research combining topic-related 
English keywords (see Supplementary Information (SI) 
Part A) identified publicly available documents and 
national websites which provide information on regu- 
lations in place. Primary and grey literature in English 
and national languages was considered, including scien- 
iific studies, reports, primary legislative documents and 
mplementing decrees as well as guidance documents. In 
parallel, regulating authorities for OWFs in the respec- 
tive countries were contacted to identify not publichy 
available information and to validate interpretations 
from the online research. In total, 70 sources of informa- 
tion were reviewed for specific regulations on chemical 
emissions from OWFs. Of these, 51 were considered in 
further analysis. The research was mainly carried out in 
the first half of 2024. We therefore present the status of 
regulations as of June 2024. 
The selection of countries is based on the partner- 
ing countries in the EU Interreg project Anemoi. Even