Limit values for diffuse radiation emitted by high-frequency devices

High-frequency devices include, for example, high-frequency heaters used in plastic welding (for example, tarpaulin presses, rain and rescue suits, storage tanks). High-frequency devices are also used in the manufacture of timber products (bending presses, plate presses and machinery for glueing beams and parquet blocks). 

The law specifies a limit value for the strength of electric fields and magnetic fields that emit diffuse radiation, which depends on the duration of daily exposure. It is the employer’s obligation to ensure that all high-frequency devices used in the workplace are inspected by specialists and that the volume of diffuse radiation that they emit is measured before the devices are used.

Inspection of high-frequency devices and diffuse radiation measurements

The purpose of inspections is to ensure that all high-frequency devices have been installed according to the manufacturer’s instructions and that instructions for the safe operation of the devices are readily available. Where diffuse radiation measurements indicate that the strength of an electric or magnetic field exceeds the limit value, inspections must be carried out and new measurements taken at three-year intervals. The date of the most recent inspection and the inspector’s name must be permanently marked on such devices.

The Radiation and Nuclear Safety Authority in Finland and the Finnish Institute of Occupational Health provide electromagnetic field measurement, training and research services.

Operation of high-frequency devices

The employer is also responsible for ensuring that all workers who operate high-frequency devices are properly trained to ensure safety and that user-friendly instructions for operating and servicing the equipment are available to the operators in the workplace.