EMF dangers?

EMF dangers?

My only concern about electric cars is the possibility of high EMFs (electromagnetic fields) inside the cabin due to the electric motor. See

I am not terribly concerned about myself but more so about the effect it could have on my kids -- since kids are more susceptible environmental toxins.

What are your thoughts on EMFs in electric cars and do we know if Tesla takes any extra precautions to mitigate the possible EMF issue?

Timo | May 13, 2011

EMF is not a toxin.

Magnetic fields in general are completely harmless, and EMF in the car is small, tiny, you get much more EMF talking to mobile or listening music in your iPod with ear buttons (that's actually a HUGE source of EMF). In fact I believe your monitor in front of you has bigger EMF field than you have from electric motor and electronics inside a car.

Tiebreaker | May 14, 2011

If I am reading the article right (on the second page):

"He said the driver was receiving “dangerously high” E.M.F. levels of up to 135 milligauss at the hip and up to 100 milligauss at the upper torso."
That would be 0.135 and 0.100 gauss respectively.

But then
0.31–0.58 gauss: the Earth's magnetic field on its surface

So is it walking on Earth's surface even more dangerous?

How about breathing gasoline fumes? And the exhaust fumes?

We are daily immersed in EMF from thousands of sources. I don't think there is a considerable risk from EMF while riding in electric cars, not bigger than walking around the appliances in your house.

David70 | May 14, 2011

Exactly Tiebreaker.

I followed the thread through and laughed when I saw the "dangerously high levels" were 100 to 135 milligauss.

J. Hawthorne | May 14, 2011

Gas cars generate EMF, too. If nothing else, spark plugs are pretty noisy. In fact, they make so much noise they wouldn't pass FCC regulations for consumer electronics. If, you know, there was an ICE in my laptop. :)

infinite_loop | May 15, 2011

I agree with the EMFs being all around you in your home, but you are not driving around inside of your toaster or sitting on top of your TV while it’s on.

Also, electric motors intentionally produce EMFs by design – that’s how they work. I’m assuming the EMFs created by the electric motor, with the several feet of coiled wired used to drive the motor that’s strong enough to propel a big heavy car forward, are much more powerful than the EMFs found in most appliances and noncoiled wiring in your home.

Anybody know of any good sources to get more information on the subject? It seems like everything I am finding is biased towards the extremes – EMFs are dangerous or EMFs are not at all harmful.

Timo | May 15, 2011

I'm leaning toward "Magnetic fields are not harmful" -party, for one very good reason: There is absolutely no scientific proof that magnetic fields cause any harm to people.

You would need a some method to transfer energy from that magnetic field to human cells and that method simply doesn't exist in magnetic fields this small. Check your clothes. I bet there is magnet somewhere. If you find one magnetic field close to that part of your body is couple of hundred, maybe thousand times higher than magnetic field inside an EV.

Also aluminum happens to repel magnetic fields, so because Model S body panels are made from aluminum you are actually better protected in it from outside EMF than in ordinary car. It also works like faraday cage, check Google what that is if you don't know.

gkimmcgary | May 15, 2011

I just love all you guys!!! I've had so much fun reading all the threads and learning, laughing... Shoot maybe even crying! I feel like I'm getting to know you all so well.. Any way my signature S can have magnetic force fields and any other life threatening doodads, and I'm still freaking stoked to own mine!! This is pretty well the sexiest piece of new technology on the planet.. That's all. Keep up the threads, I'm lovin it!

infinite_loop | May 15, 2011

Good point on the Faraday Cage. I was hoping that there would be some kind of shielding built into the Model S along those lines to specifically limit the magnetic fields present in the cabin.

I know that there are ICNIRP guidelines for exposure to electromagnetic fields.


However, these guidelines are based on the frequencies associated with the magnetic fields, and I have no idea how this would translate to the frequencies that would be produced by the Model S.

Anybody have any idea on what type of frequency ranges these electric motors produce?

Brian H | May 16, 2011

Based on the rpm figures, probably about 0.007 MHz. Average. ;)

VolkerP | May 16, 2011


if any health effects exist, they would arise from electromagnetic field. This means (of course you know) a self propagating field that interchanges between electrostatic field (measured in Volts/m) and magnetic field (measured in Gauss). The frequency of change is determined by the field emitting source and usually is constant.

I second Brian's statement that the frequency derives from the motor RPM which is 0 to .014 MHz. EM frequency might be 0 to .042MHz because it is a three phase induction motor. The generated fields interact within the motor, I don't expect much of that energy to leave the casing. EM fields may emanate from the AC cables as well but they are enclosed in the PEM next to the motor.

Magnetic fields with a broad but low frequency spectrum may emanate from the DC current in the cables (~900 Amps) from battery pack to PEM. These cables run in a pair, which helps canceling out the field in first order. If the PEM does a good job in smoothening the energy drawn from the battery, very low emission will come from this pair of cables.

Then all EM emitted by the "torque box" is shielded by the aluminum body, the higher the frequencey, the more absorption/reflection. Only low magnetic field components will travel through and they will transport very little energy. There are no reports indicating that low frequency alternating magnetic fields are harmful (e.g. from electric grid transformers).

My conclusion: If you worry about EM fields, stop using your cell phone.

Mark Petersen | May 16, 2011

No matter how well / bad they design the car it still have to pass FCC testing
I hope of cause that it will have an excellent protection off magnetic and electrostatic fields
as I want to be able to take my niece with me in the car (21 years old with a pacemaker)
but no matter what the requirement is I believe that Tesla will do there best to be well with in the legal limits for both US and EU

Douglas3 | May 16, 2011

Actually, no. Automobiles are different.

Excerpt from CFR 47 Part 15:

Section 15.103 Exempted devices.


(a) A digital device utilized exclusively in any transportation vehicle including motor vehicles and aircraft.

vperl | October 17, 2014

Someone is missing the point?

The interference one may worry about is of actual interested to owners that have an implanted medical device.a medical pacemaker, implanted cardioverter defibrillator, for a number of other implantable devices that have little computers inside.

these devices are sensitive to some security devices , like airport security and the wand or magnetic hoop one walks thru.

The concern is at Tesla Superchargers these Devices are subject to more electric interference that could lead to a total malfunction of these implanted devices. This is less than a joke if one has one of these devices implanted. Question does interference exist that could interfere with these devices operation?

that they put over the top of you

Red Sage ca us | October 17, 2014

You could always drive a wooden car with four foot drive instead...

Tabarnouche | October 17, 2014

I wear aluminium foil on my head at all times. Doesn't stop the neutrinos, though. They just go right on through...

hpjtv | October 17, 2014

@vperl maybe one shouldn't drive or be in a Tesla if they have a pacemaker. All that instant acceleration and speed can't be good for their hearts.

carlk | October 17, 2014

Doesn't all cars have alternator and electric motors to operate fans or sometimes AC, coolant pumps, etc. that all generate EMF? I'm sure it's safe long as you don't drive it over the cliff.

Brian H | October 18, 2014

Fasckinatin. Dangerous EMF at 0 Hz!

mrspaghetti | October 19, 2014

@vperl Someone is missing the point?

The interference one may worry about is of actual interested to owners that have an implanted medical device.a medical pacemaker, implanted cardioverter defibrillator, for a number of other implantable devices that have little computers inside.

I think the point missed is that one probably shouldn't rely on information from an internet forum to make life or death decisions. A couple thing I would have thought would be common sense (but apparently aren't):

1) If you have a pacemaker or other device that is sensitive to EMF, consult your doctor and the manufacturer of whatever equipment you have questions about prior to using it, and
2) If you have been exposed to Ebola, consult the CDC prior to boarding a commercial flight DON'T FLY

bobrobert | October 19, 2014

The EMF frequency in an MS is engineered to human specs – it quietly harmonizes the nervous system, easing the mind into experiencing the moment, the drive. During acceleration one's chakras light up in succession, and remarkably as each awakes the last does not dim; at top speed the final realization of harmony with the Earth Mother crowns the prolonged release of lust as one is squeezed back into the embrace of the seat.
If, however, one is startled from the transcendent state by intrusive thoughts of missing coat hooks or cup holders, contact your service center – it may be that the ion filter is not adequately purging your system of lingering ICE outgassing.

This perspective is blissfully free of any tedious fact-checking, offered merely in the pursuit of balance :)

Red Sage ca us | October 19, 2014

bobrobert: +1 UP! Coneth, my Friend! CONETH!!!

Brian H | October 19, 2014

The point is, DC current does not generate fluctuating fields. It cannot affect electronics.

chris | October 25, 2014

It seems to make sense, instead of speculating, to go buy a simple analog EMF meter (example: TriField Meter Model 100XE ) and make sure it is not exceeding the limit that would be considered by some experts to be a risk to your health or to cause a medical device functioning to be interrupted. This of course after you consult with a specialized health care provider on what the threshold limits are for those implanted electronic devices.

I have taken several in vehicle readings myself and I believe the average car to be exposing drivers to 3-5 Milligauss at the Torso area based on my readings. For long drives in any vehicle, if you are concerned, or for people with implanted electronic devices such as pacemakers you can put on an EMF Blocking Jacket to shield yourself (example:

I’m looking forward to a Model S P85D on its way and I’m confident that as with hybrids there is no difference versus the average EMF exposure in most other cars.

renwo S alset | October 25, 2014

Ah ha! This must be the reason for my testicle shrinkage! (Well, old age might have had some effect, but I really like this scientifically proven, internet supported theory, much better.)

Brian H | October 25, 2014

I expect the readings to be much lower, as the spark plugs in a Tesla fire very rarely.

renwo S alset | October 26, 2014

They're also saying on the internets that if you have your kids vaccinated, they will grow hair on the palm of their hands!
I'm sure glad my mom took the time from waitressing at the truckstop and going to revival meetings to homeschool me, so I could know this stuff.

svs | January 8, 2015

We have a Volt and a Tesla and they are interfering with one another. Neither of them will start through the key fobs when next to each other in the garage. Outside of the garage and away from one another, they both start without a problem. We are also having problems with the garage door openers. We have eliminated (by unplugging) all other electronics in the house and the problem still occurs. THIS IS A SIGNIFICANT PROBLEM FOR US. Any ideas?

1LuckyGuy | January 8, 2015

Stop worrying about what will kill you and just live. You won't beat death no matter how hard you try, but you sure can ruin life with stress.

ParklandFLMike | January 8, 2015

OP are you concerned about your kids catching fire in an ICE car?

Or how about carbon monoxide that might leak into the car?

EVBeast | January 8, 2015

All of those poor people in big cities that take ELECTRIC subways with all of their HIGH VOLTAGE every day, twice a day. They're slowly killing themselves with all of the EMF radiation from the subway cars and electrified transportation systems. Someone ought to do something about this! Government regulators should swarm in and ban all forms of electric transport!

We've been living around EMF for generations and there is no scientific link found yet (despite how hard some people try) that shows that they cause health problems.

wietse.mol | January 23, 2015

I have driven a Tesla in a test drive, and had all the metering done by a specialized company with specialized equipment. Results were as follows:

Low frequency fields, depending on acceleration between 100-1400 nT
High Frequency fields 10-700 uW/m2

Safety standards vary:
WHO: 300-400nT
UScongress: 200nT

Natural background levels: 0,0002 nT

As for the negative health consequences, saying there is no scientific evidence is mainly a result of not being informed.

Please check

For an overview of scientific research into health effects of radiation, this link can be useful:

Some 1800 scientific studies have shown a clear and significant relation between radiation exposure and adverse health effects.

I understand some of the scorn, but find it somewhat immature to ridicule the facts in favor of your own opinion.

Kind regards,

Brian H | January 23, 2015

A little radiation is good for ya. Keeps the repair systems on their toes.

sule | January 23, 2015

Oh man talk about being misinformed!

I suggest to all to refrain from all these things:

Sunlight: full of actual, measurable, radiation. Burns your skin rapidly when strong.

Air and wind: Carries airborne viruses. Can catch cold and frostbite. Not a joke. Evidence is everywhere, especially in winter.

Water: Very bad for you in larger quantities. People have actually died from consuming too much of it. (Not a joke - search it up - some poor souls competed in who can drink more water and have diluted their bodily fluids too far).

Soil: full of bacteria. That is why we wash our hands after getting dirty.

Gasoline, especially when burned in obsolete horseless carriages. Should I say more?

Earth: Has its own radiation and magnetic fields that some "informed" people say are bad.

High altitudes (even airplanes): additional sunlight radiation, reduced oxygen.



EMM? Say it is bad and it is just that we don't know that. All statistics shows that (a) people including you are exposed to it anyway, (b) the impact is negligible compared to any ONE of the above, let alone combined. So you might as well use an EV to run away from these horrible things I listed above.

sule | January 23, 2015

If you want to be a pessimist here's one for you: "Everything is killing you. Even time itself. It is just that lack of some things kills you even faster so you have to risk your life navigating through other things to get to those. So just make the best of the time you have left."

Mark E | January 23, 2015

If you are that concerned about EMF, then I suggest removing the wiring from your house, not using wifi, or going anywhere near any man made structure or where there are radio transmitters including phone towers. Good luck with that. Maybe you could build a portable faraday cage to walk around in.

I'd also suggest that people look up and read about the difference between ionizing and non ionizing radiation. Massive difference.

Just about everything is radiation of some sort, light, heat, radio, power transmission. The frequency does very considably though between 50-60Hz power transmission and ultraviolet light...

Brian H | January 23, 2015

Electrical cords, radios, TVs, computers, ovens, refrigerators, lights, and microwaves. Shun all the above, or suffer the consequences.

AmpedRealtor | January 23, 2015

"If a cat has kittens in the oven, that don't make 'em biscuits!"
- I heard that somewhere

This thread is complete and total BS.

Sudre_ | January 23, 2015

How does someone manage to post a topic on a forum about the dangers of radiation without exposing themselves to it. Sounds hypocritical to me.

lph | January 23, 2015

Great one Sudre! | January 23, 2015

It looks to me like the drive unit and related circuitry are enclosed in a a thick-walled aluminum casing. This is an excellent shield for high frequency electromagnetic fields generated by the inverter. DC current produces a static magnetic field that can affect nearby electronic circuits but not likely with sound design and system layout.

mclary | January 23, 2015

Your kids might become idiots like you and worry to much about trivial nonsense, but I wouldn't be too worried about it.

Oh they might grow an extra finger or toe!

geekdad.604 | January 23, 2015

You gotta love a news article that leads with a the caveat "Few Facts" in it's title.

tr0047 | January 24, 2015

@infinite loop
Interesting topic you brought up, and i would also like to know about EMS in the Tesla. Since i have kids too, i will like to have all sorts of knowlege to protect them.
Wietse.mol have obviously done his homework here, and got his car tested! His result doesnt scare me, but sure those measures is waaay higher than recomandation.

Standards in norway( max in daily enviroment for adults).
50 nanotesla(nT)This is magnetic field, increases with higher amperes.
10 uw/m2 wich is high frequent electric field( not from motors) from wifi, any wireless things, radars etc.

Knowlege about danger is important, i will not shut my eyes just because this is about the "no matter what perfect tesla" !
That said...i will enjoy my p85d when it arrives! But to reduce overall daily EMF to my kids and myself, i will look into other places to reduce it. Especially in my own home...its plenty of electrical components to be mesured out so i can take a qualifyed action.

And for all af you jabbing about soil, sunlight, too much water,screen radiation etc...dont bother! Im not interested in stupid exuses for not taking EMF seriousley, and that is essence of this topic.

sule | January 24, 2015

@tr0047: Noone said Tesla is perfect. You say you have children. I do too. Let me ask you: so you drive a pure EV or ICE or public transport? If not EV, have you measured the effect of the air pollution on your kids? Which do you think is worse? Also, when ICE is turned off does its pollution "disappear" like the EMF of Tesla does? How long do the effects last?

Tiebreaker | January 24, 2015

Has anybody measured the EMF field in an ICE car? Ignition cools and spark plugs make an excellent source of EMF radiation. This in addition of the toxic fumes, if you really care... | January 24, 2015

I suspect you get more radiation from a cell phone than the car. Distance is the key - the motor is about 4 feet from you through several layers of aluminum. The cell phone is typically .5 inch from you through plastic (the phone antenna cannot be behind aluminum). Radiation is reduced by the square of the distance.

Let's run some numbers - In the car, 4ft = 48 inches. 48 squared is 2304. From a phone .5" squared is 0.25. So the effect from the motor/inverter is 0.25/2304 less than the phone (if the power was the same) or 0.000010. This doesn't include the effects of the layers of thick aluminum between you and the car's motor. I have no way to quantify this, but it should be substantial.

Now we have to make some larger assumptions (you can change my assumptions to test out different scenarios). Let's assume the car uses 330 kW in an hour of operation. A typically phone has about 4 hours of talk time and a small phone typically has a 5 Wh battery. So this converts to about 5/4=1.25 Wh. We will ignore the waste heat (non-EM radiation) that both produce.

So (330,000/1.25)*.000010 = 2.8 times the cell phone.

There is a lot wrong with this analysis (that I know of). First we didn't take into account the frequencies involved. This likely has a huge effect, but again, I have no easy way to know the frequency distribution of the two items or even how to compare them in some kind of hypothetical effect.

While my rough numbers show the car might be 2.8 times that of a cell phone, it's likely far less than that once you factor in the shielding effect of the aluminum motor casing and aluminum car structure.

I'm not one who has any concerns about the levels of EMF we get in everyday life and in any EV. It's just an interesting engineering analysis, that I'm sure someone more knowledgeable can do a better job than I have.

As for the earlier comments about "tested" EMF from the car - without any details, it becomes meaningless. Was the test done at the motor casing? At the driver's position? What was the car doing - hard acceleration/coasting? Was the frequency spectrum? Did it change when driving at different speeds? Was it done in a faraday cage to ensure the measurements were not from outside sources? What was the testing equipment used and was it properly calibrated? Did the tester happen to have a cell phone - maybe they were inadvertently measuring the wrong device! | January 24, 2015

It's interesting quoting numbers. But if you don't understand the context they are meaningless.

For example, weitse.mol quoted
"Low frequency fields, depending on acceleration between 100-1400 nT"

A quick check of a Swiss study* showed that low frequency fields due to rotating tires ranged from 100-9510 nT when traveling at 80 km/h. Tires!!! No electric motors.

Look at ICE vehicles and you will see that we have been driving with some of these sources for decades.

* | January 24, 2015 - Now you just made my 1/2 hour analysis moot! Love it.

tr0047 | January 24, 2015

@ sule
I walk or cycle with my kid to kindergarten. I live 60 km outside nearest city, and airpollutin are zero to none where i live( close to nature).
I have 2 ICE and 3 motorbikes( got my doses of airpollution during the years) , and somethimes bring my son along. I know about danger of air pollution, and take my precautions!
I want to be able to take same precautions regarding EMF, therefore i dont want to trivialize it...just because i dont want it to be a problem!
By the way i totally agree about ICE air pollution...especially diesel engines produce very toxic gasses for humans! (Nox,CO,SO2,PAH and alot of other stuff like benzen and formaldehyd)

I see you have yre teories about this, and i respect that! But its complex, since EL motors in tesla gives LF radiation..and a cellphone gives HF.
Its difficult to isolate yreself from a low frequent magnetic field, alu casing around motor helps very little. On the other hand, you can isolate LF electric fields...but since we have no mesures, we let that one rest.
Anyway im glad to See that you find a cellphones radiation dangerous...that must mean you see danger in EMF.
And i will not claim EMF in a Tesla is worse than using a cellphone...but it might be!
But i am confident on wietse.mol numbers, and understand it as its mesured inside car (ofcourse) with different acceleration and speed. Thats why numbers have a low and high.

Since i am over average interested in electronics, and it was part of my education, i will try to get my hands on a instrument for mesuring EMF. Im also interesting in knowing radiation in my ICE and my house.
You know, the person you see in the mirror is the one responsibe for yre health;

sule | January 24, 2015

@tr0047: Good for you (bike, nature, ...) Otherwise, it is important to note the balance and benefits. We move towards better, not towards perfect. There isn't much choice out there. Right now EVs are better.