Electromagnetic Field Exposure: Induction Heating and Transformers

What is electromagnetic field exposure?

Every conductor carrying electric current creates an electromagnetic field around it. The field from an office computer or warehouse lighting is very weak and poses no risk. However, an induction furnace in a metal plant, a spot welding gun on a welding line or busbars carrying high current can produce a field strong enough to have an effect on the body of a person standing nearby. Electromagnetic field exposure is the assessment of working around such sources.

The electromagnetic field guide of the Directorate General of OHS at the Ministry of Labour and Social Security divides the effects into two groups:

Direct effects: Dizziness and nausea in static magnetic fields; stimulation of nerves, muscles and sensory organs (such as tingling) in low-frequency fields; heating of tissues at high frequencies.
Indirect effects: Effects the field creates on an object rather than on the person; for example, interaction with medical implants such as pacemakers, or heating or attraction of metal parts.

The guide stresses two important points: field strength falls rapidly with distance from the source, and since most fields are generated electrically, they disappear when the equipment is switched off. That is why most of the risk is controlled by managing distance and access.

Is there an electromagnetic field regulation?

This is the most frequently asked question, and the answer should be clear: Turkey has no separate OHS regulation specific to employees’ exposure to electromagnetic fields. The European Union’s Directive 2013/35/EU on this subject has not been transposed into national law, as the Ministry’s 2020 guide also notes. The exposure limits in the legislation on electronic communication devices are aimed at sources such as base stations and at public exposure; they do not provide a direct criterion for an induction furnace or transformer in the workplace.

The absence of a regulation does not mean there is no obligation. Under Art. 4 and 10 of Law No. 6331, the employer assesses all risks in the workplace; Art. 10/1-ç requires that the situation of groups needing special policies, such as disabled and pregnant employees, be taken into account. The assessment can draw on two Ministry publications prepared on the basis of the European Commission’s good practice guides: the general measures guide (2020) and the guide on sectors and work processes (2021), which contains case studies. The guides are not binding, but they explain the directive’s approach of action levels and exposure limit values: where action levels are complied with, the limit values are deemed to be complied with as well; health-effect limit values must not be exceeded under any circumstances.

Induction furnace EMF: heating, hardening and melting

Induction heating heats a metal part by passing a high current through a coil, which means a strong magnetic field around the coil. Melting furnaces, hardening machines, mould heating units and the hand-held heaters used in car repair shops to free seized bolts all belong to this group.

In the example of a small alloy production plant in the Ministry’s 2021 guide, the following measures were taken after measurement and modelling:

The area around the furnace where action levels could be exceeded was marked on the floor with paint, and employees were informed not to enter this area while the furnace was running.
“Strong magnetic field” warning and prohibition signs were posted near the furnace.
People with medical devices implanted in the body were prevented from entering the work area, and a “no medical implants” pictogram was placed at access points.

The same example also shows that small furnaces can be riskier than large ones: it is possible to stand much closer to the coil of small equipment. With hand-held induction heaters, the coil is kept away from the body, cables are not wrapped around the torso and the heater is switched off when not in use.

Electromagnetic fields in welding: spot and arc welding

Spot welding machines and arc welding operate with high currents. In arc welding, the largest source of the field is the welding cables. The Ministry guide describes a clear good practice for cable routing:

The cable is kept away from the employee’s body.
Supply and return cables are routed together as far as possible, so that the fields partly cancel each other out.
The weight of the cable is not carried on the shoulder or wrapped around the neck; this habit brings the cable closer to the head and torso and increases exposure.

For spot welding guns, it is recommended that the gun and its supply cable do not rest against the body and that hangers and balancers are used where possible. For a welder’s other risks, see our article on welders’ occupational safety risks.

Working near transformers: substations, switchboards and busbars

Transformer substations, main distribution boards, busbars carrying high current and industrial electrolysis lines are also sources of magnetic fields. The equipment table in the Ministry guide lists cable, switchgear and transformer circuits carrying more than 100 amperes, industrial electrolysis and induction heating among the sources that may need separate assessment.

When working near transformers, the electromagnetic field risk should not be overshadowed by the risk of electric shock, but nor should it replace it. Access to transformer rooms is already limited to authorised persons; this restriction also provides natural protection for employees with implants. Points next to busbars on electrolysis and plating lines where people work continuously are assessed separately; for the other risks of these lines, see our article on galvanising and electroplating.

Source	Main risk	Measure for all employees	For employees with active implants
Induction furnace and heater	Strong magnetic field near the coil	Floor marking, distance, warning sign	Access to the work area restricted; individual assessment
Spot welding	Field around the gun and cable	Keeping the gun away from the body, hangers	Individual assessment; other work if necessary
Arc welding	Field around the cable	Routing cables together and away from the body	Individual assessment
Transformers, switchgear, high-current busbars	Magnetic field, electric shock	Preventing unauthorised access	Warning at the access point; assessment before entry
Industrial electrolysis	Field around busbars	Assessing continuous work positions	Individual assessment

Pacemakers at work: employees with medical implants

Active implants (pacemakers, implantable defibrillators, neurostimulators, hearing implants) may malfunction in a strong field. According to the guide, pregnant employees and those with passive implants such as metal prostheses are also at risk in some situations. For these employees, in addition to general measures:

Notification: Employees are asked to tell the workplace physician if they have an implant. The information is health data; it stays only with the physician, and the supervisor is told only of a restriction such as “should not enter this zone”. For details, see our article on employee health information and data protection (KVKK).
Individual assessment: The workplace physician considers the type of implant, the recommendations of the treating physician and the manufacturer, and the sources the employee will approach, all together. For the approach to employees with chronic conditions, read our article on employees with chronic illness.
Access and signage: A prohibition sign for people with active implants is placed at the entrances to risk zones. This sign also applies to visitors and contractors.
New equipment: The assessment is renewed when a new induction unit or welding line is installed.

Electromagnetic fields in risk assessment: step by step

Draw up an inventory of equipment that can produce strong fields: induction, welding, electrolysis, high-current circuits, magnetic particle inspection and magnetising equipment.
For each piece of equipment, collect the electromagnetic field and implant warnings in the manufacturer’s user manual.
Observe on site how close employees come to the equipment and how long they stay.
Commission measurements if necessary and identify the zones where action levels may be exceeded.
Mark the zones, organise access, and inform employees and visitors who may have implants.
Renew the assessment when new equipment is introduced or the layout changes; see change management and risk revision.

In metalworking, foundry and automotive supplier plants in Bursa and the surrounding provinces, we address electromagnetic field sources as a separate heading within risk assessment. For other sector-specific risks, see our metal and machinery sector page, and to track assessment and measurement dates, use our OHS calendar tool.

Frequently Asked Questions

Is there an electromagnetic field regulation in Turkey?

There is no separate OHS regulation specific to employees’ exposure to electromagnetic fields; Directive 2013/35/EU has not been transposed into national law. The risk is assessed under Law No. 6331 and the Regulation on Risk Assessment; the Ministry’s 2020 and 2021 guides provide direction.

Can an employee with a pacemaker work next to an induction furnace?

This depends on the workplace physician’s individual assessment. In the examples in the guides, people with active implants were prevented from entering work areas around induction furnaces; the decision is made taking into account the type of implant and the manufacturer’s recommendations.

Is working near a transformer harmful to health?

The field weakens rapidly with distance, and access to transformer rooms is already restricted. An assessment is made for continuous work positions and for employees with implants; if necessary, the risk zone is identified by measurement and marked.

Is electromagnetic field measurement mandatory?

It is not mandatory in every workplace. Measurement is needed if the risk assessment, manufacturer information and guide tables are insufficient, or if an employee with an implant will approach a risk zone.