What is safe? The difficulty in setting EMF guidelines with precise threshold limits

Deciding what constitutes a safe level of radiation exposure from electromagnetic fields (EMFs) is not a simple or straightforward task. It is often fraught with difficulties and dynamic variables.  How do you determine a safe level when biological effects are still observed at extremely small EM signal strengths, far lower than would be acceptable for a useable telecommunications network?  To complicate matters, we are dealing with a large range of frequencies and strengths, and different combinations of frequencies, each perhaps with their own set of harmonics. We are then trying to assess a safe level by estimating the biological response of the human organism to these fields.

On top of this biological systems, human beings or otherwise, can respond in a variety of ways such as by reacting strongly to very small stimuli.  This can also depend on their state or disposition at the time which could bias their response. For example, after being inside in a darkish room for a while you will be blinded on going out into the sunlight. On the other hand, If you have been outside for a while already, you may notice nothing particularly strained in your vision as it would not appear overwhelmingly bright.   Another example might be where a tramuatised state can keep you constantly alert to danger.  It can also depend on many other factors such as health, and such things as nutritional fortitude, degree of toxic exposure, attitude of mind, etc.

Biological response becomes more complicated when considering that different frequencies also have different propagation rates, penetration depths and scattering characteristics.  On top of this different materials interact in different ways depending on their own unique permeability and dielectric properties. It is not just intensity levels that are important, frequency also plays an important role, where certain frequencies correlate with enhanced sensitivity and lower tolerance.

Despite the fact that the response of living organisms can be quite varied, being based on many dynamically changing factors, makes the particular response of individuals difficult to predict. Also, how does consistent low-level exposure compare with intermittent high-level exposure?  What happens in cases of long term exposure to levels so low you’d probably think they could never do any damage?

While ‘simpler’ biological organisms in vitro are readily shown to directly respond to very low levels of electromagnetic radiation, establishing a cause and effect relationship between EMFs and health in humans is much more difficult and complex.  Nevertheless, the fact is that living organisms respond to EMFs.

Precautionary action would favour acknowledging that there might in fact a potential risk to health, even if it is a small and subtle threat, and then take an informed and intelligent decision to alter one’s behaviour and habits accordingly to minimise any further exposure. The degree to which one chooses to adhere to these guidelines should be based on what the individual considers to be an adequate level of protection, and based on their own informed understanding as to what constitutes a ‘safe’ EMF exposure level.

From the evidence I’ve come across, I’ve decided to go with the lower and more recent biologically-based recommendations (such as the Salzburg and Bioinitiative 2012 standards which recommend levels around 1 – 10 μW/m2), and adopt some good habits now to minimise exposure in my day-to-day activities.  This should make quite a difference over the long term, e.g., like routinely carrying my phone in a brief case or backpack rather than in my pants or shirt pocket, which places it much closer to my body.

Measuring the EMF strength over a range of frequencies (broadband detector) is usually a good indicator of whether there might be a problem.  If the level is too high, or too high only in certain places, then practical steps can then be taken to effectively reduce the EMF level and overall exposure.


Inadequate Microwave Safety Standards?

The currently adopted standard from the International Commission on Non-Ionising Radiation Protection (ICNIRP) is thousands to millions of times greater (i.e., 9,000,000 μW/m2) than the limits indicated by scientific research based on the response of living biological entities.  ICNIRP looks at causal links to establish a relationship between non-ionising radation and neurological/health related responses in humans and animals.   This difference in approach and the large discrepancy in safety limits basically reflects two different schools of thought; where one seems to ignore informational electromagnetic signalling within the body, i.e., it seems to dismiss the importance of subtle electromagnetic vibrations as carriers of information.  This position also  seems to ignore the fact that living organisms are governed by very subtle electromagnetic vibrational signals, which can be disrupted by external artificial sources. The ICNIRP standard really only considers radiation levels that can cause tissue heating and neurological effects as a threshold dosage where difficulties might arise.  Unfortunately, this threshold is around 6 orders of magnitude above where biological effects are generally observed.  Or put another way, this is where living organisms normally respond to the same frequency of radiation but at much, much lower levels.

The ICNIRP guidelines were originally introduced to protect military personnel from short-term high level exposure of microwave radiation.   The guidelines clearly state that they only relate to acute and short exposures, and are obviously inadequate to address the real life situation where civilians are exposed to low-level long-term exposure.  Furthermore, they do not take into account pulsed technology that occurs with current digital broadcasting nor do these standards take into consideration frequencies other than microwaves. They also don’t take into account of the age or size of the individual.  (A child absorbs at least twice as much as an adult due to a thinner skull (easier to penetrate) and smaller diameter head (less distance to penetrate).

There are also data for chronic low level exposure that indicate that there may also be other health effects. It is, however, ICNIRP’s view that in the absence of support from laboratory studies the epidemiological data are insufficient to allow an exposure guideline to be established.

– from the ICNIRP guidelines



Power Limit (μW/m2)





ANSI C95.1 Based on thermal effects.


ANSI/IEEE C95.1-1992 Reduced level recommended earlier by IEEE in 1982. EPA still considered it seriously flawed.


FCC 5,800 mW/m2 over a 30-minute period (at 869 MHz), previously recommended by NCRP in 1986;
10,000 mW/m2 for frequencies ~2 GHz.


ICNIRP 9000 mW/m2 for 1800 MHz and
4,500 mW/m2 for 900 MHz.This is the prevalent standard in use today

The current ICNIRP standard (1998) in use today allows for much higher levels of radiation than the precautionary guidelines suggested by more recent research groups. The precautionary groups suggest levels at least 10,000 times less and around 1,000,000 times less for the more conservative limits. This is a big difference suggesting a major difference of understanding.





Biologically-based Precautionary Guidelines for Microwaves


Power Limit (μW/m2)





Salzburg Resolution Recommendation of Salzburg, Austria. In 2008, Liechtenstein adopts the goal of 0.6 V/m to be achieved by 2013.
Equivalent to 0.6 V/m.
Proposed Limit for Public Exposure to Mobile Phone Base Stations


Seletun Scientific Statement 2011


EU Parliament STOA 2001


New Salzburg Precautionary Exposure Limit Outdoor The recommendation for GSM 900/1800 mobile phone base stations updated by Salzburg Public Health. See also SBM 2008 below.
Equivalent to 0.06 V/m.
Proposed Target for Personal Precaution


Bioinitiative 2012 Recommendation BioInitiative Report 2012

New Salzburg Precautionary Exposure Limit Indoor Recommendation for indoor exposures, updated by Salzburg Public Health.
Equivalent to 0.02 V/m.
Burgerforum 1999 & London Resolution of 2007 agree with the New Salzburg Exposure Limit.


SBM 2008 Standard of Building Biology
<0.1  No Concern
 0.1 – 10  Slight Concern
  10 – 1000  Severe Concern
 > 1000  Extreme Concern


Safety Standards and Precautionary Guidelines for Power Line Magnetic Fields

In terms of power line magnetic fields, ICNIRP regulations allow for a generous AC (alternating current) magnetic field in the region of 1G (100,000 nT).  The 2010 ICNIRP report on ‘ Limiting Exposure to Time-varying Electric and Magnetic Fields’ provides reference levels of 200,000 nT (2G) for general public exposure and 1,000,000 nT (10G) for occupational exposure at 50Hz.

The public exposure limit in Ireland advised by ICNIRP (and adopted in EU directive 2013 / UK Control of Electromagnetic Fields at Work Regulations 2016) is 0.1mT (0.1 milliTesla). This is equivalent to 100 μT (100 micro tesla) or 100,000 nT (100,000 nanoTesla). The ICNIRP magnetic flux threshold limit of 100,000 nT applies to low frequency magnetic fields and power line magnetic fields in Ireland.

At the other end, the Bioinitiative Working Group and Seletun Scientific Panel recommend exposures less than or equal to 100 nT (or 1 mG). See below:


SBM 2008 (Standard of Building Biology Testing Methods)

No Concern

Slight Concern

Severe concern

Extreme concern

<0.2 mG 0.2 mG to 1 mG 1 mG to 5 mG > 5 mG
<20 nT 20 nT to 100 nT  100 nT to 500 nT > 500 nT

As a reference point, the average magnetic field strength in the average household in the UK was 0.5 mG (Powerwatch) and closer to 1 mG in the USA.  Also, Building Biology recommends and exposure limit of 2 mG and best below 0.2 mG (up to 2kHz) or  (200 nT and 20 nT respectively)

I quote:

ELF EMFs are classed as “possible human carcinogens” by the International Agency for Research on Cancer (IARC). This is mainly due to a repeated and long-term association with a doubling in risk of a child developing leukaemia at field levels above about 0.3 to 0.4 microteslas – µT (3 to 4 milliGauss – mG). The increased risk seems to start at about 0.15 microteslas – µT (1.5 milliGauss – mG).


Electric fields

The electrical field strength threshold limits are also frequency dependent. (See Table below).  The reference levels for exposure of the general public to the electrical field is set to 5kV/m at around 50 Hz to a few hundred Hz (and 83V/m at 10 Mhz).

These levels are much higher than the those recommended by Buidling Biology(?) with levels set at 10 V/m, and even better if less than 1 V/m.

(The actual electric field penetrating the brain is attenuated by 5 – 6 orders of magnitude with ICNIRP limits generally less than 0.1 V/m, e.g. 0.1 V/m occupational CNS tissue exposure to the head and 0.02 V/m at 50 Hz for the general public. (See Table 2 below)).


ICNIRP low freqICNIRP internal E fields


The SAR Rating

The Specific Absorption Rating (SAR) is a standard developed for the mobile phones industry as a means of setting a safety standard.  It is a rating not based on power density such as μW/m2 but based on the thermal effects of microwave radiation.   It is based on the concept of so much electromagnetic radiation being absorbed by so many grams of biological tissue.

There are a number of inadequacies associated with this attempt at providing a meaningful safety standard.  For one thing it considers (1) thermal damage as being the only possible effect of microwave radiation or the only reliable measure, (2) it is based on an 11 pound head of average 6’2″ tall, 200+lbs male adult, and (3) it fails to account for possible electromagnetic radiation focusing in the brain both in terms of space and time, i.e., the standard does not take into account local focusing within the brain tissue (spatial) nor does it take into account the exposure to peak pulse powers (temporal) but only their average.  In the age of pulsed technology, this is a gross inadequacy.

The current SAR standard for mobile phones in Europe (Japan and Korea) is 2.0 W/kg (and 1.6 W/kg in USA, Canada, New Zealand and Australia). The standard was based on behavioural disturbances in monkeys exposed to 4 W/kg.  The standard was also designed for only 6 minutes exposure per day.

Biological effects are seen across the full range of SAR values, i.e., in experiments where biological systems were exposed to a certain amount of microwave radiation normalised to the mass of the biological system. Effects were seen even at very low levels, well below the SAR mobile phone specification.  For example, cell phone RF was observed to cause changes in the blood brain barrier at 0.00004 W/Kg (or 40 μW/Kg) (Salford, 1997), and DNA strand breaks in rat brain cells at exposure levels as low as 0.00008 W/Kg (Kesari & Behari, 2009).