- Säteilyturvakeskus STUK
- en
- RADIATION IN DAILYLIFE
- Radiation in consumer products and appliances
Electromagnetic fields from home, school and office equipment
There are electric and magnetic fields in the vicinity of electrical appliances and wires in the home, school and office. Due to their low voltage, the electric fields are weak. Electrical appliances create a magnetic field in their vicinity, which becomes weaker very quickly as the distance increases. Homes, schools and offices also have electrical appliances that emit microwaves. These include, for example, mobile phones, wireless local area network (WLAN) devices, computers and smart meters. The modern household appliances such as refrigerators and dishwashers can have a WLAN transmitter and receiver. It connects the home appliance to a computer network, the so-called Internet of Things (IoT). Due to the low transmission power, the microwaves of these devices are weak and deteriorate rapidly as you move away from the device.
There is no health risk from electromagnetic fields from home, school and office equipment.
Data communication between the mobile phone and the base station is carried out using radio waves. The only scientifically verified effect of radio waves on tissue is warming. The warming effect in the tissue caused by mobile phones is so insignificant that it causes no health hazards.
Operation of mobile phones
Data communication between the mobile phone and the base station is carried out using radio waves. The call or other information is transmitted from the mobile phone as a radio wave to the nearest base station and from there to the fixed network. The mobile phone adjusts its transmission power depending on how good the reception is.
According to current knowledge, mobile phone radio waves do not cause health problems
The only scientifically verified effect of radio waves on humans is tissue heating. Mobile phones do not heat the tissues so much that it would be harmful to health under any circumstances.
Thousands of studies have been conducted on the health effects of radio frequency fields. Independent expert panels such as the European Commission’s scientific committee SCHEER (Scientific Committee on Health, Environmental and Emerging Risks), WHO (World Health Organization) and ICNIRP (International Commission on Non-Ionizing Radiation Protection) have published extensive literature reviews on the health effects of radio frequency fields. According to the surveys, the limit values for exposure in Finland are up to date.
Radiation safety requirements and monitoring of radio equipment worn close to the body
As an authority, STUK supervises the radiation safety of body-worn radio equipment intended for consumers. Surveillance is carried out by testing different radio equipment on the market, such as mobile phones and tablet computers. The manufacturer, importer or, ultimately, the distributor is responsible for the safety of the sold product. The manufacturer must carry out conformity assessment before placing the product on the market and is held accountable for ensuring that the product complies with the relevant requirements.
Specific absorption rate (SAR) is used as a measure of the exposure caused by the radio equipment. SAR value describes the power absorbed from the radio wave into the tissues of the head or body area. Its unit is W/kg. The maximum allowed value of 2 W/kg is confirmed by the Ministry of Social Affairs and Health’s Decree 1045/2018. The limit value is well below an exposure level that is known to cause adverse health effects.
Manufacturers of body-worn radio equipment measure the SAR value of a product and ensure that the limit value is not exceeded. In some radio equipment, the transmission power is so low that there is no need for SAR testing. Such are, for example, most of Bluetooth equipment.
The principle of SAR testing is that the measured value is at least as high as in the actual use situation causing the maximum exposure. For example, in the case of a mobile phone, this corresponds to a situation where the phone is in a poor reception area and the user is talking or transferring data, while the equipment is held either on the head or on the body.
STUK has carried out market surveillance testing for mobile phones since 2003 and for other radio equipment since 2013. Testing is performed by applying international IEC and CENELEC standards. The SAR value of all radio equipment tested by STUK has been lower than the limit value.
The Decree of the Ministry of Social Affairs and Health 1045/2018
Reports
ICNIRP (International Commission for Non-Ionizing Radiation Protection), 1998, ICNIRP guidelines for limiting exposure to time-varying electric, magnetic and electromagnetic fields (up to 300 GHz) (pdf)
ICNIRP (International Commission for Non-Ionizing Radiation Protection), 2020, ICNIRP guidelines for limiting exposure to electromagnetic fields (100 kHz to 300 GHz) (pdf)
SCENIHR/SCHEER, 2015, Opinion on potential health effects of exposure to electromagnetic fields (EMF) (pdf)
WHO, 2020, World Cancer Report 2020 (pages 88-89)
In a wireless local area network (WLAN), a terminal device, such as a computer, printer, television, game console or mobile phone, is connected to a data network or another terminal device wirelessly using microwaves. WLAN is commonly used in homes, workplaces, hotels, meeting rooms and cafes. The wireless technology is also used in teaching in schools and day care centres, as knowledge of information and communication technology and the management of Internet use are important in today's society. WLAN uses low power and therefore it is safe to use.
The wireless LAN hub is a WLAN base station or router. It also usually has a modem creating the connection to the Internet service provider’s network with a cable or through microwaves. The base station shares the network connection with LAN terminals. The base station and terminal have antennas which send and receive signals and thus enable wireless communication between devices. Due to the low transmission power, the terminal device can be within a maximum distance of 100 to 200 meters from the base station. The data transfer rate decreases as the distance increases, so several base stations must be located in different parts of the wireless LAN coverage area in order for the connection to be fast enough throughout the entire area.
Due to the low transmission power of WLAN devices, microwaves are weak even in the vicinity of the devices and deteriorate rapidly as the distance to the devices increases. Even if there are several WLAN devices in the same room, they do not cause microwaves strong enough to be harmful to the health although you would stay in the room for a long time. This means that all students in the school classroom can safely use WLAN at the same time.
The strongest microwaves are in the vicinity of the base station, as all traffic between the terminals and between the terminals and the data network passes through the base station. In addition, when browsing the Internet, information is mostly transferred to terminal devices, i.e. the base station transmits microwaves most of the time. The WLAN base station should be located away from the occupied spaces so that the connection is uninterrupted. The base station can be placed, for example, on the ceiling of the room.
Smart meters are read remotely through a wireless connection or the electricity network which enable electricity, water and gas companies to monitor the household's electricity, water and gas consumption. There are also thermometers for private use, which can be read wirelessly with a mobile phone. All wireless smart meters emit microwaves at low power and only when they are being read. Smart meters can be in the basement of the house, in the technical room or on the wall of the apartment (electricity meter), i.e. in places where you do not spend time for a long time. Such places can be, for example, the basement of the house, the technical room or the wall of the apartment (electricity meter). Therefore, the radiation from smart meters is not harmful to health.
In the induction stove, the electric current creates a strong magnetic field in the hotplate, which heats the bottom of the cookware placed on the plate. A small part of the magnetic field can be directed at the user of the induction stove. However, the exposure is low and no adverse health effects on a child, adult, pregnant woman or the fetus have been identified. However, the magnetic field may interfere with pacemakers or other active medical devices in the body.
The induction stove operates at the so-called intermediate frequencies (20,000–100,000 Hz) above the 50 Hz (Hz) frequency of the mains current. The current fed into the stove's hotplate creates a magnetic field that heats the bottom of the cookware, which is made of magnetically soft material. Thus, the hotplate does not heat up like on an electric stove, but only the bottom of the cookware. The contents of the cookware heat up quickly, as the energy is used only to heat the bottom of the cookware, not to heat the hotplate as on a traditional electric stove.
A magnetic field is generated in an induction stove only when its hotplate is turned on. The power will not be turned on if the material of the cookware placed on the plate is not suitable for induction stove or the container does not cover a sufficiently large part of the plate. Most of the magnetic field remains at the bottom of the cookware.
The induction cooker can be used safely by doing the following:
- Follow the instructions for use provided by the induction stove manufacturer.
- Use only cookware suitable for an induction stove that has the word “induction” written on the bottom or is made of cast-iron. The suitability of the cookware can be easily verified by testing whether a permanent magnet remains attached to it.
- Choose cookware the size of the hotplate and place it on the stove so that the entire hotplate is covered.
Exposure to the magnetic field of the induction stove is not harmful to the health of a child, adult, pregnant woman or the fetus.
Pacemakers and other active medical devices in the body may be interfered with when using the induction stove. Ask your doctor about the risk of interference with these devices and make sure that it is safe to use an induction stove with them.
Devices using optical radiation
Optical radiation includes ultraviolet (UV) radiation, visible light and infrared radiation.
Ultraviolet radiation (UV radiation) is classified into three sub-categories on the basis of the radiation wavelength and photon energy: UV-A, UV-B and UV-C radiation. The wavelength of UV-C radiation is the shortest and photon energy the greatest. There is no UV-C radiation in nature since the atmosphere filters the UV-C radiation completely from solar radiation.
UV-C radiation is used to disinfect air, water and surfaces in hospitals and industry. It is dangerous for humans and burns the skin and damages the eyes easily.
UV-C radiation is well-suited for disinfecting air and water. However, it is less well suited for disinfecting surfaces. UV-C radiation does not penetrate deeply, which means that it will not pass through materials well. Even a thin layer of dirt or shading prevents UV-C radiation from reaching the object to be disinfected. UV-C radiation is poorly suited for disinfecting porous surfaces. Therefore, high radiation doses must be used when disinfecting surfaces. When disinfecting surfaces, UV-C disinfection supplements other disinfecting methods.
UV-C radiation is dangerous to humans, animals and plants
UV-C radiation burns the skin and damages the eyes. Damage can be inflicted quickly, with efficient lamps in seconds. Exposure limit values for UV-C radiation are set both for public and occupational exposure. It is not allowed to exceed these values when using the UV-C disinfection. The UV-C dose required for disinfection damages both the skin and eyes and clearly exceeds the exposure limit values. It is prohibited to direct UV-C lamps towards humans. Skin and eyes must be protected in spaces that are being UV-C disinfected.
UV-C radiation is also harmful to animals and plants, so they should not be exposed to it.
UV-C radiation generates ozone. Ozone is a poisonous gas that causes respiratory symptoms and eye irritation. The amount of ozone depends on the UV-C lamp type. Sufficient ventilation should be ensured in spaces disinfected with UV-C. Ozone has a characteristic pungent odour, “electric odour”. If you can smell ozone, it is likely that there is too much ozone in the space.
UV-C radiation ages materials. It makes plastics, rubber and other materials yellow and brittle. When disinfecting with UV-C radiation, it must be ensured that the materials tolerate UV-C radiation.
Occupational exposure limit values (tyosuojelu.fi)
Public exposure limit values in Decree 1045/2018 of the Ministry of Social Affairs and Health (stuklex.fi)
Standards concerning devices
SFS-EN 62471:en Photobiological safety of lamps and lamp systems (sfs.fi)
SFS-EN ISO 15858:2016:en UV-C Devices. Safety information. Permissible human exposure (sfs.fi)
More extensive reports
Opinion on UV-C lamps of the EU’s Scientific Committee on Health, Environmental and Emerging Risks SCHEER (pdf) (ec.europa.eu)
CIE Position Statement on the Use of Ultraviolet (UV) Radiation to Manage the Risk of COVID-19 Transmission (cie.co.at)
IES’ report concerning UV-C disinfection (IES Illuminating engineering society, USA) (ies.org)
Indoor ozone
Literature survey of the Finnish Institute for Health and Welfare: Ozonization in indoor environment (julkari.fi)