Medical-fitness requirements for wind-turbine workers, including wind technicians and blade repair technicians, have developed as the wind industry has matured. EI 3583 now provides a dedicated medical-fitness framework for people who work on and climb wind turbines, whether onshore or offshore, supported by specific guidance for OEUK Medical Examiners.
EI 3583 was published by the Energy Institute in March 2025 to provide a consistent, industry-aligned approach to medical fitness assessment for wind-energy workers. It applies to personnel working on and climbing turbines both onshore and offshore.
Written and medically reviewed by Dr Farah MacDonald | Occupational Health Physician & OEUK Registered Doctor | Updated September 2026
Wind-turbine workers may encounter different certification requirements depending on their employer, project and work location. In practice, some continue to use an OEUK offshore medical with additional aerobic-fitness assessment, while others require the dedicated Wind Turbine Worker Medical under EI 3583.
Wind-turbine work can be physically and mentally demanding.
Workers may need to climb long vertical ladders, work at height, enter confined areas, wear PPE, tolerate heat, cold and adverse weather, work extended or irregular shifts and participate in rescue or emergency situations.
Offshore workers may also need to transfer between vessels and turbine structures, sometimes in challenging conditions.
These demands mean that being medically fit is only part of the requirement. Workers must also have sufficient physical capacity to carry out their role safely.
EI 3583 – Medical fitness assessment for wind turbine workers is the Energy Institute framework for assessing medical fitness for work in the wind-energy sector.
It was developed to create a consistent approach to medical assessment, terminology and fitness decisions across the industry.
The guidance applies to personnel who regularly work on and climb wind turbines both onshore and offshore.
EI 3583 separates two important concepts:
The medical assessment should be completed before physical-capacity testing.
OEUK has produced a dedicated technical note for its registered Medical Examiners undertaking wind-turbine-worker assessments under EI 3583.
Where an OEUK Medical Examiner issues the certificate, OEUK advises that the medical assessment should be carried out in person by that Medical Examiner.
Certain measurements, such as height, weight, blood pressure, visual acuity, colour vision and grip strength, may be delegated, but the medical assessment itself should not be carried out remotely.
The assessment may apply to workers whose role requires them to work on or climb wind turbines, including wind technicians, service technicians and blade repair technicians. The exact medical certification required depends on the worker’s duties, employer, project and whether the work is onshore or offshore..
No. They are different medical-fitness frameworks.
An OEUK medical assesses fitness for offshore energy work under the OEUK medical standards.
The EI 3583 Wind Turbine Worker Medical is specifically directed at the medical and functional demands of wind-turbine work.
However, OEUK notes that businesses operating offshore wind turbines are known to accept OEUK offshore medical certificates. This means some workers and projects continue to use an OEUK-based pathway, particularly where additional evidence of aerobic fitness is provided.
The certification required should therefore be confirmed from the employer, project or mobilisation instructions.
EI 3583 specifies a structured medical assessment which includes review of the worker’s medical and occupational history together with a clinical examination.
Core elements include:
The examiner also considers whether any medical condition, treatment or medication could affect the worker’s ability to perform essential duties safely, work at height, climb, work remotely or undertake associated physical-capacity testing.
EI 3583 expects medical fitness assessment to be accompanied by an assessment of physical capacity.
The dedicated physical-capacity evaluation referred to by EI had not yet been published when OEUK issued its July 2025 Technical Note.
In the meantime, OEUK advises Medical Examiners to estimate VO₂max for all examinees, using an appropriate method such as a step test.
At Marina Medicals, the Chester Step Test is used for this purpose.
Under the current OEUK technical guidance, workers should normally achieve an estimated minimum VO₂max of 35 ml/kg/min to meet the physical-capacity requirement for wind-turbine work.
VO₂max is a measure of aerobic capacity and provides an objective indication of whether the worker has sufficient cardiovascular fitness for physically demanding tasks such as prolonged ladder climbing.
At Marina Medicals, VO₂max is estimated using the Chester Step Test as part of the Wind Turbine Worker Medical.
Grip strength forms part of the EI 3583 Wind Turbine Worker Medical.
Wind-turbine work can involve climbing, handling equipment, wearing PPE, maintaining secure contact while working at height and undertaking tasks where adequate hand and upper-limb function are important.
Grip strength therefore provides an objective component of the functional assessment.
OEUK advises that grip strength should normally be at or above the fifth percentile for age and sex in the better hand.
At Marina Medicals, grip strength is measured using a hand-grip dynamometer as part of the dedicated EI 3583 assessment.
Wind-turbine technicians may work in circumstances that place considerably greater physical demands on them than ordinary workplace activity.
These may include climbing long vertical ladders, working in confined spaces, wearing PPE, working in hot or cold environments, transferring from vessels to offshore structures and potentially assisting in the rescue of a colleague.
Turbines may also be geographically remote, and workers may operate in small teams or alone. If illness or injury occurs while climbing or inside the nacelle, access to medical care and rescue may be delayed.
The medical assessment therefore considers not only whether a condition is clinically stable, but whether it could affect the worker’s ability to perform the specific duties and emergency functions of wind-turbine work safely.
Yes.
EI 3583 applies to personnel who regularly work on and climb wind turbines both onshore and offshore.
However, the occupational context remains important. An offshore worker may face additional factors such as marine transfer, remote accommodation, delayed access to medical care and offshore emergency arrangements.
An onshore worker may also work at an isolated or remote turbine location where emergency assistance is not immediately available.
The Medical Examiner therefore considers the actual location, role, transport arrangements and duties when assessing fitness.
Having a medical condition does not automatically mean that somebody cannot work on wind turbines.
Fitness is assessed individually, taking account of the condition, treatment, risk of deterioration or sudden incapacity and the demands of the worker’s role.
Conditions that may require particular consideration include cardiovascular or respiratory disease, disorders associated with loss of consciousness or balance, significant musculoskeletal problems, difficulties working at height or in confined spaces, diabetes, sleep disorders and medication that may impair alertness or performance.
Additional medical information or specialist evidence may sometimes be required before certification can be completed.
EI 3583 provides for routine medical assessment every two years, unless an earlier review is required.
Under the OEUK Technical Note, a Wind Turbine Worker Medical certificate may therefore be issued for a maximum of two years, although the Medical Examiner may issue a shorter certificate where closer medical review is appropriate.
Workers should seek further medical advice if there is a significant change in their health during the certificate period.
The correct assessment depends on the certificate requested by your employer, project or mobilisation provider.
If your paperwork specifically requires an OEUK medical plus evidence of aerobic fitness, the appropriate option may be:
OEUK Medical + Chester Step Test — £305
If the requirement is for a dedicated medical fitness assessment for wind-turbine work under EI 3583, the appropriate option is:
Wind Turbine Worker Medical (EI 3583 / OEUK) — £305
The EI 3583 assessment additionally includes grip-strength testing and certification specifically for wind-turbine work.
If you are unsure, send Marina Medicals a copy of the medical requirement before booking and we can confirm which assessment is appropriate.
No. They are different medical-fitness frameworks. Some offshore wind employers continue to accept or request OEUK certification, whereas EI 3583 is specifically designed for wind-turbine work.
Under the current OEUK Technical Note, Medical Examiners should estimate VO₂max for all examinees while the dedicated physical-capacity evaluation remains unpublished.
The current OEUK guidance states that workers should normally achieve an estimated minimum VO₂max of 35 ml/kg/min.
Grip strength is one of the specified components of the EI 3583 medical examination and provides objective information relevant to physical function.
EI 3583 anticipates a separate physical-capacity evaluation. The OEUK Technical Note states that while that dedicated assessment is unavailable, estimated VO₂max should be used as an alternative, for example using a step test. At Marina Medicals this is assessed using the Chester Step Test.
EI 3583 covers both onshore and offshore wind-turbine work, although any restrictions or conditions on an individual’s certificate will depend on their specific medical and occupational circumstances.
A certificate can normally be issued for up to two years, although a shorter validity period may be appropriate where medical review is required sooner.
Marina Medicals charges £305 for either the OEUK + Chester Step Test pathway or the dedicated EI 3583 Wind Turbine Worker Medical pathway.
Blade repair technicians may fall within the EI 3583 Wind Turbine Worker Medical framework where their work involves climbing or working on wind turbines. Check your employer or mobilisation instructions, as some projects may instead request an OEUK medical with additional aerobic-fitness assessment.
Marina Medicals provides doctor-led Wind Turbine Worker Medicals in Cardiff undertaken by an OEUK Registered Medical Examiner.
Two pathways are available depending on the certification required:
OEUK Medical + Chester Step Test — £305
Wind Turbine Worker Medical (EI 3583 / OEUK), including Chester Step Test and grip-strength assessment — £305
If you are unsure which certificate your employer requires, send us your mobilisation or employer instructions before boo
