Radiation is simply energy travelling through space. It comes in the form of either waves or particles. There are different types of wave radiation, but the most relevant to the workplace is electromagnetic. Electromagnetic radiation can be thought of as a spectrum of frequencies, with high-energy, short wavelength radiation at one end, and low energy, long wavelength radiation at the other. Sources of electromagnetic radiation can be both natural and man-made. Particle radiation – alpha and beta particles – is produced by the decay of radioactive elements, for example radon, uranium and plutonium.

These different types of radiation can be placed into one of two categories depending on their energy: ionising and non-ionising. Ionising radiation is of a higher energy than non-ionising, making it the more dangerous of the two, but in large enough doses both types can cause harm. However, most radiation exposure is not harmful because it is in small doses.

All particulate radiation is high energy and therefore classified as ionising. Some high energy electromagnetic radiation – X-rays and gamma rays – is also ionising.

The remaining broad categories of electromagnetic radiation, listed below, are non-ionising.

  • Optical radiation
    • Ultraviolet (UV) light (sources: sun beds; arc welding; UV sterilisation of food, water and equipment; fluorescent lighting)
    • Visible light (the sun, light bulbs)
    • Infrared (IR) light, often known as heat radiation (all objects emit IR radiation. The hotter an object is, the more IR radiation it is emitting)
  • Electromagnetic fields (EMF)
    • Microwaves (microwave ovens, mobile phones, GPS, radar, satellite communications)
    • Radiowaves (broadcasting, radar, radio communication, Wi-Fi)

Additionally, when electricity passes through any piece of equipment, be that a kettle or a mobile phone base station, it produces an electromagnetic wave, or field. This field of radiation, usually in form of radio or microwaves, can be large or small, powerful or harmless, depending upon the power being supplied to the equipment. Electromagnetic fields (EMF) emitted by most of the electrical equipment we come across in our workplaces and at home are unlikely to cause us harm.

Symptoms and conditions

According to the HSE, health effects caused by exposure to radiation are extremely rare and will not occur in most day-to-day work situations. The risks posed by low levels of exposure to both ionising and non-ionising radiation are small. However, exposure to high levels of either type can cause acute effects such as tissue and organ damage.

The HSE says that ionising radiation can cause dermatitis, burns, cell damage, cataracts and changes to blood. It can also damage DNA and can cause health effects, such as cancer, later in life.

The health effects of exposure to non-ionising radiation depend on the frequency of the radiation. Extremely low frequency radiation – at the low end of radiowaves – mainly causes sensory effects, such as nausea and vertigo, and nerve stimulation such as tingling and muscle contractions. Microwaves and higher-frequency radiowaves can cause exposed parts of the body to heat up, which can lead to tissue damage. Infrared radiation – a higher frequency – can cause skin burns and cataracts. And UV light – a higher frequency still – can cause burns, skin cancer, conjunctivitis and photokeratitis, a painful inflammation of the cornea also known as arc eye.


In many cases, work with equipment or substances that emit radiation will not have any effect on your health. It is radiation emitted at high levels that is most dangerous, but most applications do not emit radiation with sufficient energy to be harmful.

Exposure to ionising radiation is most likely to occur in manufacturing, construction, engineering, non-destructive testing, medical and dental sectors, education and research establishments and the nuclear industry.

Sectors most likely to see workers exposed to high levels of EMF include healthcare, energy distribution, engineering, broadcasting, transport and telecommunications.

There are a range of industries that use UV applications, including metalworking, pharmaceutical and research, printing, motor vehicle repairs, and food and drink.

Radon, a type of naturally occurring ionising radiation that is produced by uranium in rocks, is a gas that can seep out of the ground and collect in buildings, mainly underground spaces such as basements. Exposure to high concentrations increases the risk of lung cancer. Radon is recognised to be the second largest cause of lung cancer after smoking.

Certain parts of the UK are more likely to be at risk, depending on the area’s geological formation. The government has produced a radon map so people can easily find out whether their home or workplace could be affected.

What your employer should do

Just as with other health and safety risks, your employer has a duty to assess and manage the harm that could be caused by exposure to radiation. These duties are set out in the Health and Safety at Work Act and the Management of Health and Safety at Work Regulations, and require employers to reduce the risk of harm to as low as is reasonably practicable.

However, there are a number of further health and safety regulations that apply depending on the type of radiation, which place additional requirements on employers.

Exposure to ionising radiation – the Ionising Radiation Regulations 2017. These provide a framework which requires employers to reduce exposure to ionising radiation emitted by radioactive substances (including naturally occurring substances such as radon) and electrical equipment to as low as reasonably practicable. Employers should first look at ways they can alter the work process and equipment to reduce exposure, before relying on things like safe procedures or PPE.

As a further legal control, the regulations contain dose limits, legal caps on the amount of ionising radiation that people can be exposed to, with lower limits for trainees under the age of 18. There are further dose limits for the skin, the lens of the eye and the extremities. Often, it will be reasonably practicable to keep doses beneath the limit. Dose limits are a ceiling, not a floor.

Exposure to artificial light – the Control of Artificial Optical Radiation at Work Regulations 2010. These regulations require employers to assess the risks of people’s skin or eyes being damaged by hazardous sources of artificial light from all sources in all forms, such as ultraviolet, infrared and laser beams, but excludes sunlight. Using this information, employers must take steps to reduce the risk of harm.

The regulations set out exposure limit values – a maximum permitted level of exposure – for both the skin and eyes. Where this limit is exceeded, the employer must draw up and implement a plan for reducing employees’ exposure.

Exposure to EMF – the Control of Electromagnetic Fields at Work Regulations 2016. These regulations essentially cover any work where people are exposed to radio and microwaves. They place duties on employers to assess employees’ potential exposure to EMFs.

The regulations’ requirements are based on two sets of values: action levels (ALs) and exposure limit values (ELVs). ELVs are the legal limits of EMF exposure, but because they are difficult to measure, separate values, ALs, were produced which can be measured more easily. If the AL is not exceeded, exposure cannot exceed the corresponding ELV. If the AL is exceeded, further consideration and assessment is required to determine whether the corresponding ELV may be exceeded.

If the ELV is exceeded, employers must implement an action plan to reduce employees’ exposure. This could include elements such as introducing other working methods that entail less exposure to EMF; using equipment that emits less intense EMF; or providing employees with PPE.

Employers must also give special consideration to employees who are at particular risk, such as expectant mothers, or those who have declared the use of active medical devices. For these workers, they must do a risk assessment and implement the findings.

Sources of EMF which may exceed the ALs include induction heating, radio and TV broadcasting systems and devices, MRI equipment and industrial electrolysis.

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