EMF and ELF explained
Infrared sauna EMF: what the readings mean and how to check them
Questions about infrared sauna EMF are among the most common that buyers raise. This guide explains what the EMF and ELF figures in sauna marketing refer to, how they are measured, how they compare with international guidelines and ordinary homes, and what Clearlight publishes about its heaters.
In short: a reading means little without its distance and meter, and the low milligauss figures sometimes presented as limits are not official limits. Clearlight, which Sauna Republic carries, is the worked example because it publishes figures.
EMF and ELF: what the terms mean
In science, EMF (electromagnetic fields) is a broad term. The World Health Organization's International EMF Project covers electric and magnetic fields from 0 Hz to 300 GHz, from household power through radio waves and microwaves. A sauna's heaters and wiring produce fields at 60 Hz, the frequency of US household power (50 Hz in Europe), at the very bottom of that span.
ELF (extremely low frequency) names a frequency band, not a kind of field. The National Cancer Institute (NCI) describes ELF fields as those up to 300 Hz, OSHA defines the band as 1 Hz to 300 Hz, and both electric and magnetic fields occur within it.
Sauna marketing uses the labels differently: "EMF" usually means the 60 Hz magnetic field, in milligauss (mG), and "ELF" the 60 Hz electric field, in volts per meter (V/m). Sauna ELF and EMF figures therefore describe two different fields from the same heaters and wiring, so this guide names the field and unit each time.
Infrared is also electromagnetic, but these readings do not measure it. It is the radiant heat the heaters give off, which NCI lists with visible light and radio waves as non-ionizing; EMF and ELF readings measure the 60 Hz fields from the electricity.
Where the fields in a sauna come from
An infrared heater is an electrical appliance, so it produces both power-frequency fields. WHO explains that electric fields come from voltage and magnetic fields from current: "the greater the current, the stronger the magnetic field." In a sauna, that means the heaters, their wiring, controls and lighting. WHO's 2007 fact sheet adds that electric fields "are shielded by common materials, such as wood and metal," while magnetic fields "pass easily through" most materials.
Distance matters most
Both fields weaken quickly with distance. NCI notes that magnetic fields "drop precipitously at a distance of about 1 foot from most appliances." In EPA measurements from 1992, reproduced in a 2002 NIEHS booklet, a can opener's median magnetic field was 600 mG at 6 inches, 150 mG at 1 foot, 20 mG at 2 feet and 2 mG at 4 feet. These are old appliance figures, not sauna figures, but they show why a heater-surface reading and a seated reading can differ widely.
Units and reference levels in one place
NIEHS gives the conversion: 1 microtesla (µT) equals 10 milligauss (mG). Sauna marketing reports milligauss, while WHO and the studies cited here use microtesla, so an EMF milligauss figure often needs converting. Electric fields are given in volts per meter (V/m) or kilovolts per meter (kV/m).
| Reference point | Magnetic field | Electric field | What it is |
|---|---|---|---|
| Average home, Europe | 0.07 µT (0.7 mG) | Not stated | WHO average, residential (2007) |
| Average home, North America | 0.11 µT (1.1 mG) | Not stated | WHO average, residential (2007) |
| Away from appliances | 0.1 to 2.0 mG | Not stated | Typical readings reported by ARPANSA, Australia's radiation regulator |
| Top exposure groups in pooled studies | 0.3 to 0.4 µT (3 to 4 mG) | Not applicable | Research categories, not a limit |
| ICNIRP 2010, general public | 200 µT (2,000 mG) at 50 and 60 Hz | 5 kV/m at 50 Hz; about 4.17 kV/m at 60 Hz | International reference level |
| United States | None | None | No federal standard (EPA) |
ICNIRP, the International Commission on Non-Ionizing Radiation Protection, bases its 2010 guidelines on well-established short-term effects: nerve and muscle stimulation, and retinal phosphenes, a faint flickering at the edge of vision. It judged the childhood leukemia evidence "too weak to form the basis for exposure guidelines." In the United States, EPA states that "there are no federal standards limiting electromagnetic fields from power lines and other similar sources," and OSHA has no specific ELF standard.
Where the 2, 3 and 4 milligauss figures come from
Low figures such as 3 mG are sometimes presented in sauna marketing as safety limits; 2, 2.5 and 4 mG also circulate. None of the official bodies cited here, from WHO and ICNIRP to EPA and OSHA, presents any of them as an exposure limit.
3 and 4 mG: exposure groups in childhood leukemia studies
The values 0.3 µT (3 mG) and 0.4 µT (4 mG) are the top exposure groups in pooled studies comparing childhood leukemia with average magnetic fields at home. NCI reports that a nine-study analysis found a doubled risk estimate among children at 0.4 µT or more, who made up under 1% of those studied; a 2010 analysis of seven later studies by Kheifets and colleagues reported an odds ratio of 1.44 at 0.3 µT or more, with a 95% confidence interval (0.88 to 2.36) that includes no effect.
WHO concluded in 2007 that the evidence is "not strong enough to be considered causal," citing possible selection bias, no accepted biophysical mechanism linking low-level exposure to cancer, and largely negative animal studies. The most recent pooled analysis we found, by Amoon and colleagues (2022; four studies, about 25,000 cases), reported no increased risk at 0.4 µT or more (odds ratio 1.01) and a decline in the association over time.
How IARC classifies ELF fields
In 2002 the International Agency for Research on Cancer (IARC), WHO's cancer agency, classified ELF magnetic fields as "possibly carcinogenic to humans" (Group 2B), based on limited evidence in humans relating to childhood leukemia. It classified ELF electric fields, what sauna marketing calls ELF, as Group 3, "not classifiable." IARC's Q&A explains that its groups describe the strength of the evidence and "not the cancer risk at a given level of exposure."
2 and 2.5 mG, and 10 V/m: computer equipment specifications
The 2.5 mG figure matches a 1990 Swedish voluntary guideline (MPR) for computer monitors, 250 nanotesla at 50 cm, which the International Labour Office said was "not based on health or other biological aspects." The 2 mG and 10 V/m figures match TCO'99 emission requirements for computer system units, which TCO said "shall however not be taken as representing hygienic limit values." Some sauna materials call 10 V/m a "threshold of concern"; TCO'99 is the only standards document where we found that figure.
Sweden does not use these low figures as exposure limits either. It has no legal limit for power-frequency fields; according to Germany's Federal Office for Radiation Protection (BfS), Swedish recommendations correspond to the EU Council Recommendation of 100 µT (1,000 mG) at 50 Hz.
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Get PricingWhat Clearlight publishes about its heaters
Clearlight's low-EMF claims center on its True Wave heaters, which it describes as a carbon-ceramic design.
What the True Wave page reports
The True Wave page lists under 1 mG in a table headed "EMF Levels Measured Directly On Heater," says levels are "virtually 0 mG" when you sit in the sauna, and gives an average electric field of 3.4 V/m. It does not state the distance, meter or laboratory behind those figures. Clearlight's 2026 blog adds a distance, describing readings on the heater surface as "typically under 1 mG" and readings "a few inches to a foot away" as "effectively ~0 mG," again without naming a laboratory. For scale, under 1 mG is comparable to WHO's household averages (0.7 to 1.1 mG), and 3.4 V/m compares with ICNIRP's 60 Hz reference level of about 4,170 V/m.
Two commissioned heater surveys
The report linked from the True Wave page is a 2016 survey Clearlight commissioned from Vitatech Electromagnetics, an engineering firm in Virginia. It tested one 600-watt, 240-volt heater on its own, hung from a forklift at heights of 3 to 14 feet, with a three-axis gaussmeter mapping the area from 1 meter above the ground. Every magnetic reading, including the heater-off background, was below 0.5 mG, and at 3 to 4 feet readings fell to 0.0 mG, below the meter's detection resolution. The electric field peaked at 17.167 V/m one meter below the heater, against a heater-off background of about 3.9 V/m.
Our Clearlight product listings also link a second commissioned survey, which the True Wave page does not: a 2012 report by VitaTech for Sauna Works (Clearlight). It measured one 600-watt heater on 120 volts and recorded a peak of 1.96 mG at the center of the heater panel and about 0.04 mG at 1 foot. That peak is higher than the under 1 mG Clearlight publishes for readings directly on its heaters, and Clearlight does not say how its own figure was measured.
Two caveats apply to both surveys: Clearlight commissioned them, and each measured a single heater rather than a finished cabin at seated positions.
Design measures Clearlight describes
Clearlight says its Premier and Sanctuary models run wiring through metal conduit, twist wires to cancel fields, foil-shield electronic components and cover the heaters with a grounded, carbonized mesh. No official source cited here evaluates these measures. WHO's fact sheet says that for new equipment and appliances, "low-cost ways of reducing exposures may be explored," while cautioning against policies based on "arbitrary low exposure limits." Low-EMF heater design is best read in that light: an engineering choice some buyers prefer, not a health claim Sauna Republic makes.
The Curve dome
Clearlight says its Curve sauna dome uses True Wave low-EMF heating elements but publishes no separate EMF or ELF figure for it.
How to measure EMF in a sauna yourself
A handheld gaussmeter lets you check a sauna yourself, using the same structure as the 2016 survey: a background reading, fixed positions and recorded distances.
Record each reading in full: position, distance to the nearest heater, meter model, heaters on or off, and the value with its unit. Without those, a number cannot be compared with anyone else's.
Questions to ask any seller about EMF claims
A "low EMF sauna" label is only as informative as the measurement behind it. Ask any seller:
Where EMF fits in a buying decision
If low-EMF heater design matters to you, weigh it alongside these factors.
Our Clearlight saunas buying guide covers every model, and our infrared vs electric sauna heater guide helps if you are still choosing a heat source. For both in one cabin, the Finnmark FD-4 Trinity and FD-5 Trinity XL pair mid- and far-infrared heating with a Harvia traditional heater; the measurement method above applies to any electrically heated cabin.
Frequently asked questions
What is a good EMF reading for a sauna?
There is no official sauna-specific benchmark. Compare a seated reading with typical household background, about 0.7 to 1.1 mG on WHO's averages, and with ICNIRP's general-public reference level of 2,000 mG, and always check the distance and position behind any figure.
What is the difference between EMF and ELF?
Scientifically, EMF covers electric and magnetic fields from 0 Hz to 300 GHz, and ELF is the band up to 300 Hz. In sauna marketing, "EMF" usually means the 60 Hz magnetic field in mG and "ELF" the 60 Hz electric field in V/m.
Is infrared radiation the same as EMF?
Not in the sense sauna marketing uses. Infrared is non-ionizing electromagnetic radiation, the radiant heat itself; sauna EMF and ELF readings measure the 60 Hz fields from current and voltage in the heaters and wiring.
Do carbon heaters produce more EMF than ceramic heaters?
Clearlight's table lists 70 to 100 mG for "Regular Carbon Heaters" and 20 to 40 mG for "Ceramic Infrared Heaters," measured on the heater, against under 1 mG for its own. It does not publish the data or method behind those figures, and we found no comparison by anyone else. Compare any two heaters at the same distance with the same meter.
How do I measure EMF in my sauna?
Use a three-axis gaussmeter that covers 60 Hz. Take a heaters-off background reading, then read at head, lower back and calf height with the heaters on, noting each distance, and repeat. Electric fields need a separate V/m meter. See the measurement steps.
Does Bluetooth or Wi-Fi in a sauna matter?
It is a separate question from 60 Hz EMF. Wi-Fi and Bluetooth are radio-frequency transmitters, assessed in different quantities with different instruments, so a gaussmeter will not register them. The FCC notes that a Bluetooth transmitter operates at much lower power than a cell phone.
Is there an official EMF standard for saunas?
No. The United States has no federal standard (EPA), and OSHA has no specific ELF standard. ICNIRP's 2010 general-public reference levels are 200 µT (2,000 mG) for 50 and 60 Hz magnetic fields and about 4.17 kV/m for 60 Hz electric fields; they are general guidelines, not sauna-specific rules.
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Clearlight, True Wave, Sanctuary, Premier and Curve are trademarks of Sauna Works, Inc., dba Clearlight Infrared. Sauna Republic is an authorized Clearlight dealer. Finnmark and Harvia are trademarks of their respective owners. This article is for educational purposes and is not medical advice. Clearlight describes its products as general wellness products; their statements have not been evaluated by the FDA, and they are not intended to diagnose, treat, cure or prevent any disease. If you are pregnant, managing a medical condition or taking medication, consult a healthcare professional before use, and follow the manufacturer's safety guidance.
