Working with non-ionising radiation

What are the risks of non-ionising radiation?

Non-ionising radiation does not penetrate deep into the tissues but increases the risk of damage to the skin and eyes.

General risks

Dependent on the energy and exposure time, non-ionising radiation can cause localised heating, or photochemical reactions can occur with possible permanent harm. Exposure should therefore be minimised. Inappropriate or incorrect use and a wrong design increase the chances of physical harm. 

Specific risks

Risks with ultraviolet light (UV) (100 – 400 nm)
Ultraviolet light is emitted by hot light sources such as the sun, filament lamps, halogen lamps, sun beds, welding arcs (electrical welding) and gas discharge lamps (e.g. mercury lamps).
Excessive exposure mainly poses a risk for the eyes and skin. Acute effects are sunburn and cornea inflammation (welder’s flash). Long-term effects are skin cancer, skin thickening, premature aging of the skin and clouding vision (cataract). Read here which measures you can take.

Risks for visible light and infrared light (IR) (0.4 - 1000 μm)
During work at high temperatures infrared light is emitted, for example during welding, forging and glassblowing, or from heat lamps and plasma sources.
The biggest risks are for the eyes and skin. In the infrared area the IR-A area poses the biggest risk (retinal damage and ashen cataract). IR-B and IR-C are less dangerous but can also cause cornea damage after prolonged exposure. The eyes are also sensitive for excessive light. The greatest risk is in the 400-500 nm range ("blue light hazard"). Here the skin can be burnt. Read here which measures you can take.

Risks with radio wave and microwave fields (10 MHz – 300 GHz)
Sources of radio wave and microwave radiation are high-frequency generators (gyrotrons, klystrons etc.) and transmitters, microwave ovens, industrial RF heaters, radio and TV antennae, radar installations and mobile phones. Base stations for cordless phones are weak sources. 

Exposure

Exposure to electromagnetic fields in this frequency range can warm up exposed tissues because these absorb the radio wave and microwave energy and convert these into heat. The frequency level determines the depth of penetration into the body.
Warming up by this radiation is the most dangerous for the brain, eyes, genitals, stomach, liver and kidneys.
How deep the radiation penetrates depends on the frequency. If resonances occur in parts of the body then the damage can increase.
Worldwide the maximum acceptable radiation level varies from 10 mW/cm2 to 0.1 mW/cm2. FOM adheres to a maximum radiation level of 1 mW/cm2. Read here which measures you can take.

Risks with low-frequency fields (300 Hz – 10 MHz)
Up to 100 kHz only the induced current density and the internal electric field strength are important. For exposure to fields with a frequency greater than 100 kHz the specific energy absorbed is important. The energy is absorbed throughout the body but in differing degrees.
The threshold value for energy absorption, based on the induced current density and the specific absorption rate (SAR, W/kg), is 1 W/kg.

Risks for static fields and extremely low frequency (ELF) fields (0 – 300 Hz)
In general static fields are natural fields such as the earth’s magnetic field and fields created by friction.
Examples: fields develop in the direct vicinity of overhead high-voltage power lines and electrical cables, in industrial electrolysis processes and in superconducting and conventional magnets (magnetic fields).

Exposure

No biological consequences of static fields have been observed. The most significant risk is electrical shock if an object is touched. 
Static magnetic fields cause slight electrical potential differences in blood vessels. The consequences of these are unknown. 
Low-frequency variable fields generate electric currents in the body of the same size as the body generates itself and these can directly activate nerves and muscles. No lasting detrimental effects are known. 

Short-term risks

• Artificial parts or aids for the human body such as pacemakers and ferromagnetic implants (limit value 0.5 mT) can be affected. 
• Magnetic strips from bank passes, credit cards and computer diskettes (at > 1 mT) can be wiped. 
• At flux densities > 3 mT metal parts can be attracted to the magnetic field.

Long-term risks
A lot of research has been done on this. The general picture is that there is no or a very weak relationship between health and ELF. 

Which measures do I need to take?

Various aspects are important for maintaining optimum working conditions.

General measures

A number of general measures to reduce risks are given below in order of importance:

• make sure that the equipment is put together properly and well maintained;
• consider alternative techniques;
• shield off the source: encapsulate, shield off reflections (collective shielding takes priority over personal shielding);
• keep as far away from the source as possible;
• shorter exposure period by changing personnel for example;
• use personal protection equipment.

The employer should ensure there are competent personnel, good instructions and periodic information and advice. You can request this. 

Specific measures

Measures against ultraviolet light (UV) (100 – 400 nm)
Exposure to UV light in the workplace should be prevented.

• Use collective shielding for permanent or temporary set-ups. Most types of plastic (including Perspex) and aluminium sheets can be used as shielding. Test the material in advance for permeability.
• If shielding is not possible then use the right personal protection equipment such as goggles, clothing or suntan creams.
• For welding work protective gloves and clothing are prescribed.
• During the use of UV sources (including UV lamps) warning signs should be present and free access to the room must be hindered.

Measures against visible light and infrared radiation (IR) (0.4 - 1000 μm)

• Shield off the heat source.
• Use the personal protection equipment specifically designed for this (clothing and eye protection).

Measures for radio wave and microwave fields (10 MHz – 300 GHz)
A better design and shielding of the source are the most effective methods for reducing the exposure. Absorbent clothing is not always effective. At risky locations the local expert takes measurements or calculates if the norm isn’t exceeded and if necessary closes off the risky area. 

Measures for static fields and extremely low frequency fields (ELF) (0 – 300 Hz)

• Place warning signs for employees and visitors with pacemakers and ferromagnetic implants.
• Use stainless steel equipment if applicable.
• Keep analogue watches, credit cards, flash drives, fire extinguishers et cetera out of magnetic fields.

Legislation

European Directive 2004/40/EC of 29 April 2004. This also provides limit values and action values for exposure to electromagnetic fields. This directive came into force in 2012. The limit values from this directive should never be exceeded.