Household background magnetic field (50/60 Hz)
Away from appliances, homes typically sit below a few milligauss; the WHO's epidemiological association with childhood leukaemia begins at a daily average of 3–4 mG (0.3–0.4 µT).
Last verified 12 August 2026.
Also searched as: background EMF, ambient magnetic field
- Category
- elf magnetic
- Emission bands
- Power frequency
- Environments
- home
- Duty cycle
- Continuous, varying with household and grid load; evening peaks are common.
Field strength by distance
- 1 m
- 0.1–4 mGMeasured range — Range commonly reported in residential surveys away from appliances and service equipment. Values above this usually indicate a specific source: service panel, wiring error, or an external line.sources: niehs-emf, who-elf
Mitigations, most effective first
- Log for 24 hours rather than spot-reading; use the 95th percentile of night-time values for a bedroom assessment.
- Power-frequency fields track load and vary hour to hour, so spot readings mislead.
- Walk the perimeter with the meter to find the source before considering any mitigation.
- Elevated background is nearly always one identifiable source, most often the service panel or a net-current wiring fault.
Measure with
- ELF gaussmeter (power-frequency magnetic field)
- Logging EMF instrument
Related records
- WHO/IARC ELF magnetic field association threshold (0.3–0.4 µT)
The average daily exposure level above which pooled epidemiological studies report an association with childhood leukaemia, and the basis for the IARC Group 2B classification of ELF magnetic fields.
Exposure limits
- Building Biology SBM-2024 AC magnetic field bands
Sleeping-area grades at 50/60 Hz: below 0.2 mG no anomaly, 0.2–1 mG weak, 1–5 mG strong, above 5 mG extreme.
Exposure limits
- ELF magnetic field survey
A source-finding walkthrough plus a 24-hour log, because power-frequency magnetic fields track electrical load and a spot reading answers almost nothing.
Measurement protocols
Sources
- niehs-emf Electric and Magnetic Fields — National Institute of Environmental Health Sciences. government, link checked 2026-08-12.
- who-elf Electromagnetic fields and public health: exposure to extremely low frequency fields — World Health Organization, 2007. government, link checked 2026-08-12.
- sbm-2024 Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024) — Institut für Baubiologie + Nachhaltigkeit (IBN), 2024. ngo, link checked 2026-08-12.
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