After CES 2015, I wrote a post, concerned about the increasing prevalence of wireless charging technology and the unknown health risks of wireless charging, but I didn’t have any measurement tools with me to gauge the actual EMF emissions. At CES 2016, I did bring my meters to measure the wireless charging EMF levels.
EMF Levels From Two Types of Wireless Chargers
I measured chargers based on the two primary tech standards battling for dominance in the consumer device charging market (e.g., phones, tablets, etc.) where the device is intended to make contact with the charger. I have not had the opportunity to measure emissions from any wireless chargers that are designed to charge at a distance.
The two technologies I measured are Qi (pronounced ‘chi’) and Rezence. And it turns out that there are massive differences in emissions from these two technologies.
The wireless chargers I measured based on the Qi standard emitted, at max, 3 milligauss (mG). And when no phone was touching the charger, the emissions were effectively 0 (meaning, when nothing was being charged, the charger emitted nothing, which is a great feature). I measured multiple devices based on the Qi standard, from different manufacturers, and found the same results. And, as expected, the power of those emissions diminished significantly with distance. A few inches away, and you’re already under 1mG.
Then I measured emissions from Rezence chargers, and the results were far more concerning. In stark contrast to the Qi chargers, the chargers I measured based on the Rezence standard emitted at least 100 mG. I say ‘at least’ because 100 mG is the max measurement on the Trifield meter I brought with me.
Even more troubling, I measured that same reading whether any devices were charging or not. In other words, the wireless chargers I measured based on the Rezence standard, emitted at least 100 mG all the time, whether or not they were actually charging anything.
100 mG is 100x the maximum exposure recommended by the BioInitiative Working Group. So, Rezence chargers emit 2 orders of magnitude above the exposure recommended by this group of international scientists based on their review of thousands of peer-reviewed scientific studies. It really is a massive level of EMF emissions in the ELF (extremely low frequency) range of the spectrum.
I did reach out to both Qi and Rezence. Rezence did not reply. In contrast, Qi replied that their lower emissions are intentional, the product of their superior engineering, a fact that they attempt to explain in greater detail in this post.
While I believe any additional EMF exposures are of potential concern (precisely because they are additive to all the other exposures we already have from our phones, WiFi, smart meters, cell towers and so forth), there is clearly a massive difference between the risks of these two standards. Until Rezence changes their basic engineering design, I would strongly recommend avoiding any wireless chargers based on that standard.