EMFBase
Sources & emitters

Fluorescent tube lighting

Ballast-driven tubes measured 20–100 mG (2–10 µT) at 15 cm, falling to at most 30 mG (3 µT) at 30 cm — relevant because the fitting is often directly above a desk or bed rather than at arm's length.

elf magnetichomeworkplaceschool

Last verified 12 August 2026.

Also searched as: fluorescent tube EMF, strip light EMF, CFL EMF

Category
elf magnetic
Emission bands
Power frequency; Electronic ballast switching
Environments
home, workplace, school
Duty cycle
Continuous while lit; magnetic ballasts hum at the power frequency, electronic ballasts add a switching frequency in the tens of kilohertz.

Field strength by distance

15 cm
20–100 mGMeasured range — Measured range at 15 cm from the fitting (2–10 µT) in the EPA's 1992 survey of 60 Hz appliances, dominated by the ballast rather than the tube.sources: nrc-1997-appliance-fields, epa-1992-appliance-fields
30 cm
0–30 mGMeasured range — The strongest fitting measured 30 mG (3 µT) at 30 cm; the weakest was indistinguishable from background.sources: nrc-1997-appliance-fields, epa-1992-appliance-fields

Mitigations, most effective first

Mount the fitting at ceiling height rather than in a desk or under-cabinet lamp within 30 cm of the head.
Normal ceiling separation puts the ballast beyond the distance at which it is distinguishable from background.
Measure with an instrument rated above 2 kHz if the fitting uses an electronic ballast.
A power-frequency gaussmeter reads near zero at the ballast's switching frequency, producing a false negative.

Measure with

  • ELF gaussmeter (power-frequency magnetic field)
  • Intermediate-frequency magnetic field meter

Related records

  • LED lamps and low-cost drivers

    The switch-mode driver inside a cheap LED lamp can put measurable high-frequency harmonics on the circuit and produce visible flicker; well-filtered drivers do neither.

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  • 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).

    Sources & emitters

Sources

  1. nrc-1997-appliance-fields Possible Health Effects of Exposure to Residential Electric and Magnetic Fields, Table 2-3: magnetic-field strengths of common household appliances — National Research Council (US), National Academies Press, 1997. peer-reviewed, link checked 2026-08-12.
  2. epa-1992-appliance-fields EMF in Your Environment: Magnetic Field Measurements of Everyday Electrical Devices (EPA 402-R-92-008) — U.S. Environmental Protection Agency, Office of Radiation and Indoor Air, 1992. government, link checked 2026-08-12.

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