Their sources and exposure limits
Electric and magnetic fields are found wherever there is electricity: in our homes and workplaces and near power lines.
Learn about the strength of electomagnetic fields
See how quickly the electromagnetic field strength diminishes as you move away from the
Choose an electromagnetic field source out of the following and move the person around the landscape to see how quickly the field strength diminishes at you move away from its source.
Exposure near 120 kV overhead line depending on distance
| Distance (meters) | Exposure (microteslas) |
|---|---|
|
45 m |
0.08 µT |
|
30 m |
0.21 µT |
|
15 m |
0.98 µT |
|
0 m |
3.2 µT |
Exposure near 315 kV overhead line depending on distance
| Distance (meters) | Exposure (microteslas) |
|---|---|
|
80 m |
0.06 µT |
|
60 m |
0.14 µT |
|
40 m |
0.04 µT |
|
20 m |
1.8 µT |
|
0 m |
6 µT |
Exposure near 735 kV overhead line depending on distance
| Distance (meters) | Exposure (microteslas) |
|---|---|
|
150 m |
0.28 µT |
|
120 m |
0.43 µT |
|
60 m |
1.6 µT |
|
40 m |
3.4 µT |
|
0 m |
12.5 µT |
Exposure near 120 kV underground line depending on distance
| Distance (meters) | Exposure (microteslas) |
|---|---|
|
15 m |
0.05 µT |
|
10 m |
0.1 µT |
|
60 m |
1.6 µT |
|
5 m |
0.6 µT |
|
0 m |
3 µT |
What are the recommended exposure limits?
In Canada and Québec, there are no regulations setting safety standards for exposure to electric and magnetic fields. Exposure limits are therefore based on the recommendations of two international organizations:
- The International Commission on Non‑Ionizing Radiation Protection (ICNIRP).
- The Institute of Electrical and Electronics Engineers (IEEE).
The ICNIRP and IEEE have set limits for occupational exposure to electric and magnetic fields as well as exposure of the general public but do not specify maximum exposure duration. Electric and magnetic fields induce very weak currents in the human body. The purpose of the exposure limits recommended by the ICNIPP and the IEEE (which have large safety margins) is to limit these induced currents to levels that present no health risks.
Note that the IEEE and the ICNIRP do not recommend the same exposure limits for alternating current (AC) electric and magnetic fields at the frequency of our electrical system (60 Hz) because they used different models of the human body to calculate the limits.
Units of measure used
Electric fields vary depending on , expressed in volts (V), and are measured in volts per metre (V/m). Magnetic fields vary depending on , expressed in amperes (A), and are generally measured in microteslas (µT).
Recommended guidelines for the population
Electric fields
| Fields | ICNIRP | IEEE |
|---|---|---|
|
60 Hz |
4.2 kV/m |
5 kV/m* |
|
Static |
No recommendations |
|
Magnetic fields
| Fields | ICNIRP | IEEE |
|---|---|---|
|
60 Hz |
200 µT |
904 µT |
|
Static |
0.4 T |
0.118 T |
*Maximum authorized of 10 kV/m under high‑voltage lines.
Sources:
- ICNIRP. Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz).[PDF 642 kB] International Commission on Non-Ionizing Radiation Protection. 2010.
- IEEE. C95.1-2019 – IEEE Standard for Safety Levels with Respect to Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 Hz to 300 GHz. New York, IEEE, 2019.
Recommended guidelines for workers
Electric fields
| Fields | ICNIRP | IEEE |
|---|---|---|
|
60 Hz |
8.3 kV/m |
20 kV/m |
|
Static |
No recommendations |
|
Magnetic fields
| Fields | ICNIRP | IEEE |
|---|---|---|
|
60 Hz |
1,000 µT |
2,710 µT |
|
Static |
2 T |
0.353 T |
Sources:
- ICNIRP. Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz). [PDF 642 kB] International Commission on Non-Ionizing Radiation Protection. 2010.
- IEEE. C95.1-2019 – IEEE Standard for Safety Levels with Respect to Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 Hz to 300 GHz. New York, IEEE, 2019.
Did you know?
We are all exposed on a daily basis to numerous artificial magnetic fields generated by our electric appliances. The strength of these fields is generally no greater than 30 microteslas (µT) and they do not last long. For example, using a hair dryer generates about 30 µT, a microwave about 20 µT and a toaster about 1 µT.
Don’t forget that an MRI (magnetic resonance imaging) scan at your local hospital will likely expose you to a static magnetic field of about 2 million microteslas (2 T) for several minutes without discomfort or damage to your health.
Pacemakers and automatic implantable defibrillators
International standards support the conclusion that cardiac implants operating normally are not affected by electric fields of up to at least 5 kV/m or magnetic fields up to at least 100 microteslas (µT), depending on how the implants are programmed.
In general, the recommendations of the ICNIRP and the IEEE do not specifically address the question of medical devices such as cochlear implants, neurostimulators, metal prostheses and insulin pumps.
Hydro‑Québec has its own well-established procedure for assessing safe return-to-work of employees wearing pacemakers or automatic implantable defibrillators.
Pacemakers and implantable cardioverter defibrillators
Duration: 5 minutes 46 seconds
Pregnant women
There are no health regulations or recommendations specifically addressing exposure of pregnant women to electric and magnetic fields. Exposure limits for pregnant women are therefore the same as for the rest of the population.