Types and Effects of EMF Radiation
Electromagnetic fields (EMFs) are all around us; produced by electrical equipment, industrial machinery, medical scanners, and communications systems. While many EMFs are harmless at low levels, certain environments may expose workers to stronger fields that could affect health or interfere with medical devices.
Under the UK’s Control of Electromagnetic Fields at Work (CEMFAW) Regulations, employers are required to assess these risks and ensure that exposure stays within safe, scientifically recognised limits.
This page explains the different types of EMF radiation, the biophysical effects of exposure, and why it’s important to monitor EMF levels in professional environments.
What is EMF Radiation?
An Electromagnetic Field (EMF) is generated whenever electrical or electronic equipment is in use—this includes everything from mobile phones to industrial machinery. EMFs are present in almost every workplace, and while most are harmless, high-intensity fields may pose a risk depending on their type and frequency.
Main Types of EMF
- Magnetic Fields (Low Frequency) – Common in environments with large electric motors, transformers, rail systems, power stations, and industrial processes.
- Electric Fields (Low to Mid Frequency) – Typically found near high-voltage equipment such as power distribution networks and electrified railways.
- Electromagnetic Fields (Mid to High Frequency) – Includes radiofrequency (RF) radiation from base stations, radar, broadcast transmitters, scanners, and RF heating systems.
Additional Definitions
- ELF (Extremely Low Frequency) – Frequencies below 100 Hz, such as those produced by mains power (50/60Hz). Exposure limits apply even where health effects are not conclusively proven.
- MRI – Magnetic Resonance Imaging uses strong static and RF fields in the tens of megahertz. Staff working near these scanners may require exposure assessment.
What Are the Effects of EMF Exposure?
While long-term health effects of EMF exposure remain the subject of ongoing research, short-term biophysical effects are well established and are the focus of regulatory limits under the CEMFAW Regulations.
Two Main Categories of Effects
- Thermal Effects – Tissue heating caused by absorption of high-frequency EMF energy. Typically occurs at frequencies above 100 kHz.
- Non-Thermal Effects – Stimulation of muscles, nerves, or sensory organs, more common below 10 MHz. Effects can include vertigo, tingling sensations, or nausea under high field strengths.
Real-World Implications
In most everyday work environments, exposure remains well below the levels required to cause these effects. However, employers are legally required to assess EMF risks and ensure fields stay within safe exposure limits—especially in sectors such as healthcare, energy, rail, telecoms, and manufacturing.
For more information, refer to the HSE publication A Guide to the Control of Electromagnetic Fields at Work Regulations 2016 (HSG281).
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