Hengstmann et al. Environmental Sciences Europe (2026) 38:20

Minimum requirements
The general goal of minimizing emissions from OWFs is
already part of country-specific and transnational regulations,
 but should be further specified for chemical emissions.
 In a first step, minimum requirements may focus
on selected topics e.g., corrosion protection measures or
regulatory approaches. As a basis, regulations concerning
 chemical emissions that are already in place, like the
ban of biocides in coatings (several countries) and rules
for minimizing microplastic emissions (Belgium and
Netherlands), may be adapted in other North Sea bordering
 countries. A source-based approach for regulating
 chemical emissions in combination with detailed
emission studies on actual emissions in offshore projects
 (Germany) may help to extend rules specifically
for chemical emissions from OWFs. The preference for
ICCP instead of GACP (as expressed by Germany and
France) may be one solution to reduce the emission of
metals but may introduce halogenated compounds [25].
However, information on potential emissions from ICCP
and their impacts on the marine environment is scarce.
Future studies need to provide more and transparent data
in order to better assess the impact of alternative technologies
 such as (but not restricted to) ICCP in a possible
process of harmonization of regulations.
Consequently, a next step is to phrase minimum
requirements for regulating emissions of chemicals from
OWFs depending on the applied techniques (sourcebased
 approach).

Monitoring and data needs
Having a comprehensive overview of applied chemicals
on OWFs and their ingredients can be beneficial for the
estimation of chemical emissions and their impacts. As
shown in a review by Hengstmann et al. [21], there is a
lack of scientific data on the composition of chemicals
used in specific offshore wind applications (e.g. coatings)
as well as chemical emissions and their ecotoxicological
 assessment. Further research and international databases
 on chemical contaminants from OWFs are needed.
When national authorities require lists of planned and
used chemicals in OWFSs in the authorization process
(building on the procedures already in place in Germany
and Belgium), this information may help in identifying
chemicals that may be of concern. Furthermore, chemicals
 that lack data for risk assessment for the marine
environment should be evaluated before they are utilized
in OWFs. The more information on chemicals and their
emissions and impacts will become available, the better
they can be evaluated.
Moreover, data on emissions and their impacts on the
marine environment should be gathered in general. Monitoring
 during the operational phase is an important tool

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to do so and could be inspired by established monitor-\ng
 procedures used in other sectors, like offshore oil and
gas. Results from monitoring can help determine emissions
 more precisely, identify those contaminants that
show large releases, enrichment in water, sediment or
biota and/or are of concern due to potential impacts on
the environment. Overall, increasing the knowledge on
chemical emissions from OWFs through monitoring and
research, as well as sharing data on chemical substances
used and monitoring results publicly, may contribute to
the goal of reducing emissions of prioritized chemicals.
On that account, there is a need to monitor and study
chemicals from OWFs scientifically to extend knowledge
on the emissions and better assess their occurrence and
effects in the marine environment.

Balance between regulation and innovation
With additional data gained by an overview of applied
chemicals in OWFs and monitoring programs, new innovative
 technologies may be developed, designs already
in use can be optimized and Best Available Techniques
(BATs) may be revised and improved to limit chemical
emissions. It is important to review regulations and BATs
cegularly to ensure that they reflect the latest findings
and adapt them, if necessary. Adapted and optimized
regulations and techniques could then address specific
emissions in order to minimize pollution. When implementing
 harmonized regulations, it should be considered
though, that these do not impede innovation of different
techniques but still allow for their development. The difäculty
 of reconciling regulation and innovation is a crosssectoral
 issue. So-called “experimentation spaces” can
ensure greater flexibility in a protected regulative environment
 [13] and could also be applied in the offshore
wind sector. At the same time, fragmentation in regulations
 between countries is also known to hinder innovation
 [17] so that harmonization may also be beneficial in
this respect.
Therefore, adaptation and expansion of guidelines, regulations
 and BATs with increasing knowledge on chemical
 emissions from OWFs must go hand in hand with
sufficient scope for innovation and feasibility.
Coordination efforts
rurther development of regulations addressing chemical
emissions from OWFs should also take into consideration
to harmonize rules transnationally aiming towards the
minimization of impacts on the environment already in
che design phase. A harmonization of regulations would
also be beneficial for developers and operators that manage
 OWFs in various countries. However, it is important
to clarify to what extent regulations can be established
on an overarching level. Chemical emissions will spread