Hengstmann et al. Environmental Sciences Europe (2026) 38:20 
determines specifications for carrying out environmental 
impact assessments. 
Considering country-specific regulations, impacts from 
OWFs on the marine environment with respect to bio- 
diversity or specific organisms are often mentioned (e.g. 
"8, 9, 34, 36]). In contrast, specific sources for chemicals 
introduced into the marine environment are less fre- 
quently addressed in regulating documents. Also, these 
rules differ among countries with respect to detail, scope 
and extent. The variation in regulatory approaches, con- 
cerning authorisation processes and especially rules for 
chemical emissions from OWFs, was also shown by other 
authors (e.g. [21, 38]). Hengstmann et al. [21] further 
compared the legal frameworks for Germany, the UK and 
the US. Their results showed that neither the UK nor the 
US have specific regulations for chemical emissions from 
OWFs, but individual licence conditions and other legal 
frameworks will regulate chemicals used in OWFs on a 
broader scale. In the following, the regulations on moni- 
toring approaches and specific chemical emission sources 
are compared for Belgium, Denmark, France, Germany, 
the Netherlands, and Norway. Special attention is given 
to two regulatory aspects in the spotlight chapters, to 
underline the differences in approaches across countries. 
In general, monitoring approaches are implemented 
and/or required for OWFs in several countries, but the 
focus and the responsible authority differ, Monitoring 
focusing on water quality and biological aspects (ben- 
thic communities, fishery resources, marine mammals, 
chiropteran activity) is required to be undertaken by the 
project owner during the lifetime of the project in France 
"1, 26, 28]. In contrast, a monitoring of metals in water, 
sediment and benthos is recommended but not required 
in France [1, 28]. Similarly, monitoring programs in other 
countries are rather concerned with biological aspects 
but do not consider chemical emissions. For example, in 
Germany, assessments of impacts on benthos, birds and 
marine mammals must be carried out by the operator 
during the construction and the first ten years of opera- 
tion of OWFs [5, 43]. In the Netherlands and in Belgium, 
monitoring is required by law and research and monitor- 
ing programs to assess ecological and biological effects 
of OWFs (WOZEP and WinMon.BE, respectively) have 
been established by national authorities [10, 35]. Like- 
wise, an environmental monitoring program has been 
implemented in Denmark to analyze long-term and 
cumulative effects on specific species [7]. 
Corrosion protection systems are considered one of 
the major input pathways for chemical emissions from 
OWFs [21]. Therefore, it is important to have regula- 
tions on their application. However, such regulations are 
only rarely defined in the evaluated countries and often 
lack specific, enforceable requirements at this point. 
Page 49f9 
For example, regarding the use of coatings for corro- 
sion protection of offshore wind structures, the Dutch 
regulations recommend that epoxy coatings with little 
to no release of specific compounds should preferably 
be applied [22]. Similarly, Belgium, French and German 
rules require coating material which is as pollution-free 
as possible and/or forbid coatings and paints that include 
tributyltin and other biocides (e.g. [4, 19, 28]). The ban of 
tributyltin, an organotin compound which was frequently 
used in antifouling paints for ships, was implemented in 
2008 by the International Convention on the Control of 
Harmful Antifouling Systems by the International Mari- 
time Organization (IMO) [40]. 
Besides coatings, anodes are applied at OWFs to pre- 
vent corrosion of steel structures [24], especially for sub- 
merged areas [41]. Galvanic anode cathodic protection 
(GACP) systems based on zinc as major compound are 
prohibited in Germany to reduce the input of respec- 
tive metallic components into the marine environment. 
Instead, aluminum-based galvanic anodes, minimizing 
the zinc content as well as other impurities, are allowed 
and, if possible, impressed current cathodic protection 
(ICCP) systems are preferred due to their very low metal 
emissions [4]. As the release of metallic compounds from 
galvanic anodes was observed, monitoring of any metallic 
contamination from OWFs and considerations to apply 
ıCCP systems to minimize any emission of metals is rec- 
ommended in France [1, 28]. In other countries in this 
study, specific rules for the application of anodes have 
not yet been introduced. 
Spotlight 1: source-based approach 
in Germany, a source-based approach considers different 
input pathways for chemical emissions from OWFs and 
defines specific rules for their avoidance or minimisation 
4]. This includes for example scour protection measures, 
wastewater and drainage systems or cooling circuits. 
At the same time, operators are required to submit an 
emission concept during the approval stage of OWFs in 
Germany, which summarizes possible emissions from 
different sources and avoidance strategies. During pro- 
‚ect development, this concept needs to be updated in the 
form of an emission study, containing the actual emis- 
sions. Additionally, a list of all operating materials on the 
wind turbines and platforms must be submitted [4]. Such 
a source-based approach addressing various possible 
sources for chemical emissions is not yet established in 
regulatory frameworks of other countries considered in 
this analysis. A similar approach with respect to the list- 
ing of materials, is available in Belgium, though. Here, a 
list of all hazardous and noxious chemicals planned to be 
used shall be submitted for approval to the supervisory 
committee (e.g. [19]).