My phone has a wireless charging coil, and it got me thinking about how much EM radiation a charger would actually produce. I'm sure some tinfoil people are up in arms about it, and a quick Google reveals this:

[a representative from Intel said] that “these are just magnetic fields— they’re not going to make you sterile” (unfortunately, there’s quite a bit of science demonstrating evidence to the contrary)— that’s not unusual, as many in the wireless industry are not aware of (and do not wish to be made aware of) the increasingly large body of science demonstrating health risks from their technology. (source)

and in the comments,

By analogy, we are in the 1950s of the tobacco industry, with ads extolling doctors’ recommendation of which brand to smoke. Due to the trillions of dollars of profit from the microwave RF industry, we are likely to follow a similar path before it’s widely accepted that wireless kills.

Although even some pro-wireless companies write about this, the above quotes come from a website that clearly has an agenda against RF/EM signals: they sell shielding. Their specific claim is (emphasis mine):

EMF can destroy DNA, cause cancer and infertility, and is listed by the World Health Organization as a Class 2B Carcinogen. In fact, major global insurance companies are refusing to insure phone manufacturers against health claims. And few people know that Apple says you’re not even supposed to hold your iPhone against your head. (source)

Does RF/EM signals really "destroy DNA, cause cancer and infertility"? Is this really a "Class 2B carcinogen"?

I don't personally believe that "wireless kills" and I'm guessing it would be similar to microwave and wifi radiation and that the power decreases exponentially with distance.

For the sake of argument, let's set up a specific case: say I use a wireless charger on my nightstand - 8 hours of use every night, 50cm from my head. Is this harmful as the "Shield your body" sites would imply??

  • 4
    I think this question is abundantly answered in the WiFI and Microwave posts. Also, it confuses induction chargers (which have a specific EMF frequency) with EMF in general which include everything from radio waves to gamma radiation
    – Sklivvz
    Jan 14, 2016 at 9:53
  • 3
    To @Sklivvz's point: It is very likely that some forms of EMF (like the microwaves in your microwave oven) can destroy DNA, some forms (like the UV from the Sun) can cause cancer, and others (like the wireless chargers) are of no significant harm at all. We don't want to tackle a strawman, which is why we ask for a specific claim.
    – Oddthinking
    Jan 14, 2016 at 12:44
  • I understand and respect the need to uphold a certain standard, so I'm not complaining, @Oddthinking. Your latest comment already summarizes key points, so perhaps someone could back it up with sources. Jan 14, 2016 at 18:55
  • 1
    @Sklivvz WiFi has much lower intensity and microwave ovens are already shielded, so I would argue this is a sufficiently different situation that needs to be verified/falsified independently. I don't know the power of those wireless chargers, but if it's large and not properly shielded, perhaps they could cause microwave burns. Wikipedia cites a source that microwave burns can lower sperm count.
    – gerrit
    Jan 18, 2016 at 11:33

1 Answer 1



Probably no.
Unless it was powerful enough to cause damage through heating or immediately shock you.

About wireless charging

For most cellphones, wireless charging is done according to Qi or PMA standard:

Whereas the Qi standard works over the approximate frequency range of 100-200 kHz, the PMA (Power Matters Alliance) standard delivers up to 5 W over almost twice that frequency

The used frequency belongs into Low Frequency band. Low Frequency band is included in Intermediate Frequencies. Guidelines don't seem to focus on this frequency range very much. Everything relating to "Low frequency" I found was about "Extremely Low Frequency" (power lines).

World Health Organization on Intermediate Frequencies

For the purpose of this document, the intermediate frequency (IF) region of the EMF spectrum is defined as being between the ELF and RF ranges; 300 Hz to 10 MHz. A relatively small number of studies has been conducted on the biological effects or health risks of IF fields

Research about health focuses on other EM frequencies

I'm using less reliable links here, because it doesn't relate to wireless charging. The links are also more general, just to explain where some of the scary claims about EM frequencies would apply

Within RF (wiki):

Outside RF:

  • Ionizing radiation (causing DNA damage and cancer) or intermediate non-ionizing that still produces some ionization (wiki)

Health effects of Low Frequency radiation

World Health Organization talking about Low-frequency electric fields (added highlighting):

Heating is the main biological effect of the electromagnetic fields of radiofrequency fields. In microwave ovens this fact is employed to warm up food. The levels of radiofrequency fields to which people are normally exposed are very much lower than those needed to produce significant heating.

So, the main problem would be heating. But it probably isn't heating.

The heating effect of radiowaves forms the underlying basis for current guidelines. Scientists are also investigating the possibility that effects below the threshold level for body heating occur as a result of long-term exposure. To date, no adverse health effects from low level, long-term exposure to radiofrequency or power frequency fields have been confirmed, but scientists are actively continuing to research this area

And if it's not heating, it probably isn't harmful.

World Health Organization on Intermediate Frequencies (added highlighting):

Except for medical diagnostic and treatment devices, levels of human exposure from IF devices normally fall below limits recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP).

While strong fields in the upper IF range may cause thermal damage (a relatively slow process that requires tissue to be maintained at high temperatures for a given period of time), some of the most obvious hazards from acute exposure to electric currents in the body may occur through membrane excitation. This non-thermal mechanism results from changes in membrane potential induced by external fields and occurs, for example, in the stimulation of peripheral nerves and muscle cells. Another mechanism is electroporation, which is the reversible or irreversible disruption of cell membranes when a field induces excessive electrical potentials across them. This can provoke tissue injury through electric shock

Unless you are immediately getting shocks or automatic nerves firing.


By analogy, we are in the 1950s of the tobacco industry, with ads extolling doctors?

They only successfully bought TV ads with doctors. Analogy is implying that they successfully bought peer-reviewed journals and scientific consensus.

Is this really a "Class 2B carcinogen"?

Yes, World Health Organization talking about health risks associated with mobile phones and their base stations (added highlighting):

RF fields have been classified by the International Agency for Research on Cancer as possibly carcinogenic to humans (Group 2B). Studies to date provide no indication that environmental exposure to RF fields, such as from base stations, increases the risk of cancer or any other disease.

AAAS criticised WHO's bad explanation of the terminology in Cell Phones Offer Lessons in Risk Communication:

"That classification represented “the weakest result they could come to,” without clear evidence to disprove a connection, Gray said, yet the terminology may confuse people.

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