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Bioelectromagnetism
TABLE 7.3 Reference Levels in ICNIRP Guidelines for Low Frequencies (Unperturbed rms Values)
Exposure Characteristics
Frequency Range
E-Field Strength (kV/m)
Magnetic Flux Density (T)
Occupational exposure
1–8 Hz
8–25 Hz
25–300 Hz
300Hz to 3kHz
3 kHz to 10 MHz
General public exposure
1–8 Hz
8–25 Hz
25–50 Hz
50–400 Hz
400Hz to 3kHz
3 kHz to 10 MHz
20
20
5 × 102/f
5 × 102/f
1.7 × 10−1
5
5
5
2.5 × 102/f
2.5 × 102/f
0.83 × 10−1
0.2/f2
2.5 × 10−2/f
1 × 10−3
0.3/f
1 × 10−4
0.04/f2
0.5 × 10−2/f
0.2 × 10−3
0.2 × 10−3
0.08/f
0.27 × 10−4
Source: Reproduced from ICNIRP, Health Physics 99: 818–836, 2010.
Notes:
1. f in Hz.
2. In the frequency range above 100 kHz, RF-specifc reference levels need to be considered additionally.
TABLE 7.4 Reference Levels in ICNIRP Guidelines for Low Frequencies for Time-Varying Contact Currents from
Conductive Object
Exposure Characteristic
Frequency Range
Maximum Contact Current (mA)
Occupational exposure
−2.5 kHz
1.0
2.5 kHz to 100 kHz
0.4f
100 kHz to 10 MHz
40
General public exposure
−2.5 kHz
0.5
2.5–100 kHz
0.2f
100 kHz to 10 MHz
20
Source: Reproduced from ICNIRP, Health Physics 99: 818–836, 2010.
Note: f is the frequency in kHz.
Te reference levels in Table 7.3 are derived from the basic restrictions referring to published data
of computational dosimetry results (Dimbylow, 2005, 2006). In the computation, millimeter resolu
tion anatomical human models were used, and the conditions of maximum coupling of the feld to
the exposed individual, i.e., uniform feld exposures, were assumed to provide maximum protection.
An additional reduction factor was considered in the derivation of the reference levels to consider the
dosimetric uncertainty.
As can be seen in Table 7.5, the reference levels in the ICNIRP guidelines (2010) are expressed in terms
of electric feld strength (kV/m) (1 Hz to 10 MHz), magnetic feld strength (T) (~10 kHz), and contact
current (mA) (~10 MHz).
Apart from the direct efects of EMFs, “indirect efects” are also considered in the guidelines. Te
indirect efects involve a human touching an object where the electric potential of the object is difer
ent from that of the human body. In the guidelines, reference levels limiting the indirect efects of EMF
have also been given for frequencies up to 10 MHz expressed as contact current to avoid shock and burn
hazards in Table 7.4. It should be noted that the reference levels are not intended to prevent perception
but to avoid painful shocks.
7.7.2 IEEE Safety Standard
Te IEEE safety standard for low-frequency electric and magnetic felds was originally established in
2002 as IEEE standard C95.6 and revised along with that of high frequency as C95.1 in 2019 (IEEE, 2019).