EMF from LED Lights – Magnetic Fields and Recessed LED Lights

Lutron Dimmer 2" away

EMF from LED Lights and Recessed LED lights

Is there significant amounts of EMF from LED Lights?

A designer client of mine had a job she was working on, where her client, a homeowner, was concerned about the magnetic fields in her home.  She was designing a remodel, which included the kitchen, and the designer had specified recessed can lighting in the kitchen.  The homeowner’s son’s bedroom was located directly above the kitchen and several of the can lights.  The designer wanted to specify LED lights not only for energy efficiency, but also light quality, brightness, and color saturation (as compared to CFL or other choices). The question asked was “Should we worry about EMF from LED lights? Are low frequency alternating current magnetic fields, and would any fields propagate far enough to affect the occupants in the kitchen or the bedroom above?

The designer and I went to a San Francisco lighting showroom and tried to test several models on display.  However, due to the large number of light fixtures, all energized at the time of sampling, the background MF readings were so high as to make any readings we made useless.  So we picked out two possible candidates for her client’s kitchen and purchased the LED engines & housings, and a dimmer switch.  Our plan was to hook up the can lights and test in a cleaner environment, one in which the background EMF was minimal.

The units purchased were:

Halo Brand Model EL-405827, 15 Watts

Cree Brand Model CR 4E-15, 9.5 Watts

A Lutron Diva CFL-LED DVCC-153P-WH dimmer was used with both units.

Measurements were taken with a Tenmars Triaxial Magnetic Field Meter Model TM-192D.

Turns out, by no accident, that my home has very low background EMF.  I set up a test platform and took readings of both LED lights with the dimmer attached.  I de-energized all the other circuits in the house except the circuit to power the test, to further reduce background EMF.

First, I took several background readings with the LED lights powered off. Not all LEDs are the same, and EMF from LED lights varies considerably.

Background EMF from LED Lights turned off

Background EMF from LED Lights turned off


Next, I energized each LED light and took magnetic field measurements at 2” and 12” with the dimmer set at full.  Then, I next dimmed the lights to the dimmest setting and again measured the MF at 2” and 12”.  I then measured the MF at the dimmer switch at 2”, 12” and 24”.  The results are as follows.


MF Reading in milligauss(mG)                   2” 12” 24”
Power OFF 0.25 mG Average
Halo EL-405827 Full Bright 0.80 mG 0.25 mG
Halo EL-405827 Dimmed 0.30 mG 0.25 mG
Cree CR 4E-15 Full Bright 0.65 mG 0.25 mG
Cree CR 4E-15 Dimmed 0.33 mG 0.25 mG
Lutron DVCC-153P-WH 2.72 mG 0.70 mG 0.25mG


Halo-Full Bright

Halo-Full Bright


EMF from LED Lights

Lutron Dimmer 2″ awa

EMF from LED Lights Analysis

The dimmer appears to produce the strongest and largest magnetic field, starting at 2.0 mG and not receding to background levels until 24 inches away.

Both LED can lights produced a measureable magnetic field, but the strength was low, below 1.0 mG and dropped to background levels at 12 inches away.  This is not surprising as magnetic fields are directly related to the amount of current running through a device and both of these lights are low wattage devices, with the Halo drawing 15 watts and the Cree 9.5 watts at full bright settings.  The lower readings of the Cree are likely due to the decreased wattage of this model.  This would also explain the lower MF readings when dimmed, as when dimmed the devices draw less current, and thus produce lower magnetic fields.

As these lights are going to be installed in a ceiling, presumably at least an 8-foot ceiling, the effect on occupants in a kitchen should be minimal, as most people will be over 12 inches away from where the fields have a measurable increase over the background.  For the floor above the effect should be the same.  The floor joists should be at least 8-10 inches and thus, even lying on the floor above, one would be close to 12” away from the lights in the ceiling below.  Standing, sitting, or on a bed, any occupant would be much farther than 12” away from the LED can lights and thus the effect of the magnetic field generated by these lights should be negligible, and any field measured should be indistinguishable from the background.

It is worth noting that the Cree model did not dim smoothly and cut out completely at low settings.  The Halo model dimmed much lower and more smoothly.  This could be due to the dimmer used, but the representative at the lighting showroom said the Lutron dimmer was appropriate for both LED models.

I would conclude that from an energy efficiency standpoint, light color and quality, and EMF exposure, I would be comfortable recommending both LED recessed can light models for any remodel or retrofit project.   I have no reason to believe that any other model or brand of LED light would be dissimilar, as they are all low current devices, and thus should not emit high levels of MF, and that the field should dissipate into the background within 12”, if properly manufactured, wired, and installed.

Let us know if you’d like an EMF expert to evaluate EMF from LED lights and other appliances in your home or workplace.

11 Responses to “EMF from LED Lights – Magnetic Fields and Recessed LED Lights”

  1. Alex Stadtner says :

    Most dimmer switches do produce high voltage transients (“dirty electricity”) and some may be in the RF bandwidth.
    Each switch is different, and outside of a controlled laboratory it’s often difficult to isolate the dirty electricity coming off switches compared to ambient readings.
    To further complicate matters, dimmers usually connect to lights with ballasts and sometimes fancy lamps with built-in electronics that can also produce dirty electricity and RF.
    Simple advice, if you think a dimmer is bothering you swap it out for a simple on/off switch or try another dimmer.
    You could also experiment with various line conditioners (“dirty electricity filters”) like Green Wave or Graham Stetzer Filters, etc.
    Good luck!

  2. Laura says :

    I have heard that dimmer switches cause strong RF fields. You can check this simply by bringing a cheap RadioShack radio (that doesn’t cancel static) turned to am up next to dimmer switches to “measure” the RF by hearing the amount of static produced.
    I would be interested to know the RF produced by these if any.
    I myself have a lot of problems with dimmer switches. Or did – as I’m getting better.
    I’ve heard many people have problems with LED lights and not sure the source.

  3. Amir Cooper says :

    Thank you for what you checked !
    Do you know how much emf there is in compact florescent ?
    Thank you very much

  4. free says :

    Interesting. Trying to decide what to do due to the extreme health problems I have had due to emf. I suggest visiting this site.

  5. Alex Stadtner says :

    Hello Geraldine,

    Buzzes are common with lighting transformers. Often the transformers are powered up even when the light (lamp) is off. It’s likely the buzz was from a lighting transformer. Might have an electrician check or simply replace that transformer to address this acoustic issue.

    An “almighty magnetic force.” Wow! That sounds awesome. But I’m sure you didn’t want it in your bed. How do you know there was a momentary force? Did you feel it? See it? Hear it? Have a meter?

    For this latter EMF phenomena we’d need to know more about the problem. Sounds interesting and I hope we can help.


  6. Geraldine Keith says :

    We have down lights in our bedroom, they were all turned off. I had just got into bed and heard a ‘buzz’ coming from one of the down lights and then there was this almighty magnetic force that came down across the bed (only lasted for a matter of a second). Do I call in an electrician to do a voltage reading? Your comment would be greatly appreciated.

  7. Jill Buffie says :

    Syrena: the EMF’s you are sensing are most likely from your stove (believe it or not, gives off quite a bit) and your microwave. get an inexpensive Gauss meter online and see for yourself. You’ll be shocked. We were!

  8. Syrena says :

    Please disregard my comment, submitted, yesterday, as I found your other blog posts about the question I was asking. Also want to inform you that many people may feel ill from LED lighting, if they have issues with migraines or neurological problems, like seizures, because LED lighting is a strobe light, or pulse width modulation. http://www.theledlight.com/PWM-pulse-width-modulation.html

    Love your website and blogs. Very informative. Thank you!

  9. Syrena says :

    Thank you for this. I am wondering why I feel ill with our new Cree LED lightbulbs in the kitchen chandelier over the kitchen table. There are five, 40 watt, soft light bulbs in the chandelier. Any chance that you can do a check on these, too, and post about it? I’m quite worried about why I feel ill. Maybe EMF’s? Maybe just need to adjust to a different type of lighting, as I’m used to incandescent? I don’t know. I appreciate any insights on this. Thanks!

  10. David Sasse says :

    I have not checked dimmers for RF and Voltage transients, but that is a great idea and I will set up an experiment and perhaps write another blog post.

    I do know some dimmers emit fairly strong magnetic fields, and I do not recommend having them located within 3 feet of a bed.


  11. Mikko Ahonen says :

    Thank you for an informative and well-done magnetic field measurement report.

    Related to dimmers: I would be curious to read about voltage transient & RF radiation measurements. Do you David happen to know any? I have tried to do these measurements with a spectrum analyzer but my results have been so far inconclusive.

    Several of my clients get headaches close to dimmers and that is why I ask.

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