Welcome to EMF UK - compact fluorescent lamps.

EMF UK - Electromagnetic Fields UK is dedicated to providing simple and cost effective solutions for reducing any potential risk caused by the presence of electromagnetic fields within the home and workplace. 

Compact Fluorescent Lamps (CFLs)

CFLs are becoming prevalent in the home due to their claimed energy-saving technology. Indeed, there are strong indications that they may become the only, or at least by far the most common, light source available for home use. They are similar to traditional fluorescent lamps with one important difference; they contain an RF oscillator running at a frequency of tens of kilohertz. For this reason EMF UK decided to test the EMFs produced by readily available CFLs.

No claims are made for the strict scientific accuracy of these tests; single samples of randomly chosen lamps were tested in a domestic environment (which is where they will be used after all). Nevertheless, the results are regarded as being reasonably typical and the comparisons between different lamps as being valid.  The results are intended to provoke further comment or testing of CFLs in general; they should not be  regarded  as endorsing or condemning individual models of lamps. Please note that anybody wishing to test CFLs for themselves will require a meter responsive to the the VLF range (e.g. the ELF-3830 available from the EMF UK shop). - a standard ELF meter will provide incorrect results.

Those interested in the technical details will find the descriptions and results of the tests further down the page. Individuals experiencing sensitivity to CFLs may find the comparisons useful. (If in any doubt, health issues should always be referred to a doctor).  The following summary is the opinion of EMF UK based on the results of those tests and other freely available information.


It is the view of  EMF UK  that if compact fluorescent lights must be used, they should be avoided as reading, desk or bedside lamps. The lamps should be kept at least one, and preferably two, metres away from the individual as a precaution until such time as the lamps are proved safe.

Advantages of CFLs.

  • Lower energy requirements, claimed to be only 20% of that used by incandescent lamps.
  • Greater life expectancy, perhaps 5 times that of incandescents.
  • Lower costs for consumers.
It is demostrably true that CFLs produce much less of their energy output as heat than incandescent lamps but it is questionable how much of that heat is wasted. If you have the lamp on on a Summer day with the windows open then the heat is wasted. How many people have their lights on under those circumstances? If, however you have your lights on in the Winter, in the dark, in your snugly insulated home with the windows closed the 'wasted' heat is in fact providing background heating. You can turn your fire down, or the thermostat  on your heating will turn off a llittle earlier. If this is taken into account, the energy saving suddenly looks a lot less than 80%! And of course the energy required to manufacture CFLs is higher than that for incandescents, further reducing the claimed energy savings.

Currently, CFLs do last considerably longer than incandescents. They are also many times more expensive. CFLs are not inherently more reliable, in fact since they contain a much larger number of components they may turn out to be less reliable if sold at the same price point. The reliability of any electrical appliance is governed by the price point it is sold at, and the profit margins of the manufacturer and retailer.

CFLs generally have a poor power factor. Depending on your energy supplier, this may result in electricity charges higher than  expected. Combined with the factors outlined above, the savings will inevitably be less than a superficial calculation would suggest.

Disadvantages of CFLs.

  • Many  CFLs emit UV light. There have already been cases of individuals who have rested close to a lamp and suffered 'sunburn'! UV light is known to be detrimental to human skin and eyes.
  • They have a warm-up time of a minute or more. Consequently, they are not recommended for use in locations such as stairs or hallways. And they're not much use as outdoor approach lamps which are normally only on for short periods of time. Some manufacturers warn that constant switiching on and off will shorten the CFLs' life. Of course, you could avoid these problems by leaving them switched on all the time....
  • All CFLs that EMF UK is aware of emit EMFs, and most if not all of those at RF frequencies. EMFs are more damaging at these frequencies than at mains supply frequencies.
  • If the frequency of the CFL is close to that of your TV remote control, the latter may be somewhat temperamental in operation. Or perhaps this is a healthy advantage - you will definitely get more exercise!
  • Many CFLs (and fluorescent lights in general) cannot be dimmed. Those that can be dimmed may not do so effectively. Whereas you might have previously dimmed your incandescent lamp and saved energy, this option  may not now exist.
  • Your pet may not like them. CFLs have been tested and shown to produce ultrasonic noise which can disturb household pets such as cats and dogs.
  • CFLs have poor power factors which may reduce cost savings and increase losses in the power distribution system..
  • They may feed  high frequency signals and their harmonics back into the electricity supply - so-called 'dirty electricity'.
  • They contain toxic chemicals, particularly mercury. This results in greater disposal costs (both financial and environmental) at the end of their life. EMF UK is aware of the argument that power stations introduce mercury into the atmosphere and that the energy savings may result in a smaller amount of mercury being produced over the life of a CFL. But isn't the aim to move towards renewable energy sources to reduce emissions? How then will less mercury be produced? 

There is sufficient evidence available to suggest that a precautionary approach should be taken towards EMF exposure. With homes already containing EMFs from multiple sources (many of which may be beyond the occupants' control) such as the power system, electrical appliances, cordless and mobile phones, wifi and an ever-growing list of 'essential' gadgets,  why are the public being effectively forced to introduce yet another source of EMFs into their homes in return for negligible energy savings and some serious disadvantages?  

The Tests.

As the tables of results would not fit comfortably on this page, they have been posted on this webpage (opens in a new window). 

Electric Field measurements.

A Combinova EFM100 electric field meter was used for these measurements. The VLF  range was selected and measurements taken in a repeating mode at distances of between 0.1 and 1.3 metres from the lamp. Before each new test, the lamp was allowed to warm up for 3 minutes. Two hundred readings were obtained for each lamp at each distance and, provided the readings did not differ by more than a few percent, the final reading was recorded.  Background noise was recorded at less than 0.2 V/m throughout the tests.

The fields from the lamps reduced to below 1 V/m at distances beyond around 1.3 metres. Fields close to the lamps differed by a factor of roughly 3 between the highest and lowest readings. These results may be compared to recommendations in the ICNIRP guidelines. The recommendations for the frequencies used by CFLs are very much lower than those for incandescent lamps - a maximum of 87 V/m at typical CFL frequencies, compared to 5000 V/m  for electric power (50Hz) distribution in Europe.  It can be seen from the table that it would be difficult to reach these field levels unless very close to the lamps. Using the lamps as desk or reading lamps could result in exposures of up to 30% of the ICNIRP limit however.

The ICNIRPguideline is not the only limit that should be considered. The Combinova meter was chosen for this test  for a reason. In addition to general use it is also specified for testing computer display units (originally of the CRT rather than LCD variety), for which standards exist.  If you are reading this on a computer monitor there is likely to be a sticker on the frame with the TCO logo; TCO'03 or TCO'99 for example. These standards specify values for ergonomics, display quality, ecology and EMF emissions. A maximum electric field of 1 V/m at a distance of 0.3m in front of, and 0.5m around, the display is specified. This precautionary value is included in the TCO standards adhered to by most of the world's display manufacturers. It can be seen that the value is exceeded by a factor of 5 to 25 by the CFLs in these tests.  The table indicates that  to keep exposure below 1 V/m it is necessary to keep beyond a distance of 1 or 2 metres from the lamps.

Magnetic Field measurements.

A Spectran NF5010 was used. Magnetic fields were measured in microgauss using the 3D sensor at distances of between 0.1 and 1.0 metres from the lamp. In each case the reading was allowed to stabilise for one minute and the final value recorded. Background noise was recorded at less than 1 microgauss throughout the tests.

The results are summarised in the table. They are in all cases well below the ICNIRP recommendation of 6.25 microtesla (6.25 microtesla is equivalent to 62.5 milligauss or 62500 microgauss).  The TCO recommendations for diplays are very much lower at 25 nanotesla (250 microgauss) at a distance of 0.5 metres . None of the lamps exceeded this figure at this distance (these tests were not performed with fully TCO-compliant equipment however).. One of the lamps produced magnetic fields around 40 times higher than the others.

Waveforms and Harmonics.

A Velleman PCS100 was used to observe waveforms and perform a FFT analysis of their harmonic content. In each case an 'aerial' (merely a short length of wire) was positioned a few centimetres from the bulb and the resultant screen images recorded.

The waveforms recorded on the oscilloscope were far from sinusoidal, as expected from the crest factors recorded by the Combinova. All the lamps produced a more or less triangular waveform from their oscillators and it was expected that many harmonics would be present. The FFT analysis showed that this was indeed the case, with the third harmoic showing the highest peak and discernible harmonics produced all the way up to 1 MHz. A significant proportion of these harmonics can be expected to find their way back into the mains supply, contributing to the 'dirty electricity' regarded by many as contributing to issues of poor health.

Power Factor.

Although not strictly related to EMF issues, the power drawn and the power factor for each lamp were measured on a standard plug-in energy monitor of the type available from most large electrical stores.

The energy monitor demonstrated the poor power factor of these lamps, barely above 0.5 in one case. Also, the measured power consumption could be noticeably different to the nominal power rating printed on the packaging. Poor power factors may lead to higher than expected electricity charges and greater losses in power distribution.