If you have researched home saunas, you will have seen “low EMF” stamped across the marketing. A low EMF infrared sauna is one built to keep the electromagnetic fields around your body as small as possible while it runs. The claim sounds reassuring, but it raises a fair question: are EMFs actually a concern in a sauna, and if you care about them, how do you check a cabin properly rather than trusting a label? This guide gives you the honest version.
EMF stands for electromagnetic field. Any electrical appliance produces one when current flows, and an infrared sauna is no exception because its heaters draw a lot of power. The fields people worry about are extremely low frequency (ELF) magnetic fields, at the 50Hz of UK mains electricity.
How EMFs are measured
Magnetic fields are measured in microtesla (µT) or, more often in the sauna world, in milligauss (mG). The two convert simply: 1mG equals 0.1µT. Sauna brands quote milligauss because the numbers look larger and are easier to compare, so that is the unit you will see on spec sheets and test reports.
To give those numbers meaning you need a reference point. That is where the guideline levels come in.
What the safety guidelines actually say
Public exposure to power-frequency magnetic fields is governed by guidelines from the International Commission on Non-Ionizing Radiation Protection (ICNIRP), which UK bodies follow. The ICNIRP reference level for general public exposure to a 50Hz magnetic field is 200µT, equivalent to 2,000 milligauss. An older European recommendation sets it at 100µT, or 1,000 milligauss.
Put that next to real saunas and the picture changes. Even an older cabin with ceramic heaters typically reads in the tens of milligauss at the body, and a modern carbon-panel sauna reads in single figures. Both sit far below the ICNIRP public guideline. In other words, mainstream infrared saunas are already well within the internationally recognised limits, and there is no established evidence of harm at the field strengths a sauna produces.
So why does “low EMF” matter to buyers?
Two reasons, and it is worth being straight about both. First, some buyers take a precautionary view: you sit close to the heaters for 30 to 45 minutes, several times a week, so minimising exposure is a reasonable personal preference even if the levels are within guidelines. Second, “low EMF” has become a quality signal. A brand that engineers for low fields has usually also invested in better heaters, wiring and controls.
The building-biology community, which takes the most cautious stance, aims for under about 2 to 3 milligauss at the head and chest. That is the target the stricter “low EMF” and “ultra-low EMF” products are chasing.
What makes a sauna low EMF
- Carbon panel heaters. Modern carbon-fibre panels spread the heat over a large surface and generally produce lower fields than the older, more concentrated ceramic rod heaters.
- Twisted-pair and shielded wiring. Running the supply and return wires twisted together cancels much of the magnetic field they would otherwise create.
- Heater and control placement. Keeping wiring and the control board away from where your back and head rest lowers the reading at the seat.
As a rough industry guide, readings above roughly 20mG suggest an older or poorly shielded design, 3 to 10mG is typical of a decent modern carbon sauna, and under 3mG is what premium low-EMF models advertise.
How to check a sauna’s EMF yourself
Do not take the label at face value. There are two ways to verify:
- Ask for third-party test data. A reputable brand will publish independent measurements taken at the bench and backrest, not just next to a single heater. Be wary of a single “peak” figure with no location given.
- Measure it in use. A consumer gauss meter or triaxial EMF meter (the TriField TF2 is the common choice, usually 150 to 200 dollars) lets you read the field at your actual seated position once the cabin is up to temperature. Measure where your lower back, torso and head sit, because that is what you are exposed to, and take the reading with the heaters running, not cold.
If you are weighing up a cabin for a home wellness space, our wider buying advice is on the Shape House homepage, and the underlying exposure guidelines come from ICNIRP.
Does low EMF change how well the sauna works?
No, and this is worth being clear about because the marketing can imply otherwise. A sauna’s benefits come from the infrared heat that warms your body and raises your core temperature, not from the level of the stray magnetic field around the wiring. A well-designed low-EMF cabin heats you just as effectively as a higher-EMF one; the difference is only in the incidental field, not the therapy. So you never have to trade warmth or performance for lower EMF.
The reason low-EMF cabins often feel like better saunas is indirect. The engineering that reduces the field, spread-out carbon panels rather than a couple of hot ceramic rods, twisted-pair wiring and thoughtful heater placement, also tends to produce a more even, comfortable heat across a larger surface. That even coverage is what you feel. Heater type is the biggest single factor here, and our guide to carbon versus ceramic infrared heaters goes into how the two compare on heat quality as well as EMF. If you are choosing a cabin, treat low EMF as one marker of a well-built product rather than the whole reason to buy.
Frequently asked questions
Are the EMFs in an infrared sauna dangerous?
Mainstream infrared saunas produce magnetic fields well below the ICNIRP public guideline of 200µT (2,000mG), and there is no established evidence of harm at those levels. Choosing low EMF is a precautionary preference rather than a response to a proven risk.
What is a good low EMF reading for a sauna?
Decent modern carbon saunas read around 3 to 10 milligauss at the body, and premium low-EMF models aim for under 3mG. The strictest building-biology target is under about 2 to 3mG at the head and chest.
Do carbon heaters really lower EMF?
Generally yes. Carbon-fibre panels spread heat over a larger area and, combined with twisted-pair or shielded wiring, tend to produce lower magnetic fields than the older concentrated ceramic rod heaters.
How do I measure EMF in a sauna?
Use a consumer gauss meter or triaxial EMF meter such as a TriField TF2. Run the sauna up to operating temperature, then take readings at your seated position where your back, torso and head rest, rather than next to a single heater.
What does milligauss mean?
Milligauss (mG) is a unit of magnetic field strength. One milligauss equals 0.1 microtesla. Sauna makers quote milligauss because it produces larger, easier-to-compare numbers than microtesla.
Is a low EMF sauna worth paying more for?
If you value the precaution or want the better heaters and wiring that usually come with it, yes. If you are reassured that mainstream saunas already sit within safety guidelines, you may prefer to spend the difference on size, wood quality or a fuller heater layout. Either way, ask the supplier for independent field measurements taken at the bench and backrest, so you compare cabins on real data rather than the marketing headline.