ICNIRP 2010
(still not up to current tech specs)
Who are ICNIRP?
ICNIRP are the International Commission on Non-Ionizing Radiation Protection. They issued guidelines on exposures in 1998 that covered the frequency range up to 300 GHz. In 2009 they issued a draft revision for consultation and in 2010 they issued new guidelines for the frequency range 1 Hz to 100 kHz together with an accompanying Factsheet.
Importantly, their guidelines are not intended to be a complete system for protecting the public that should be applied in different countries as it stands. They say that their guidance considers only the science, and Governments will need to look at other factors before deciding whether and how to implement the guidelines. Thus, for example, the EU Recommendation uses the numbers out of ICNIRP 1998 but expects them to be applied only where the time of exposure is significant.
What do the guidelines say?
For the first time, ICNIRP distinguish central nervous system (CNS) effects - basically the head - from peripheral nervous system (PNS) effects - the rest of the body. They give different basic restrictions for each. They set the occupational levels, then for the general public, they apply an extra factor, generally 5 but in one case 2.
They also give reference levels. These are not the actual limits, they are simply guidance figures for when it is necessary to investigate the basic restriction. The reference levels are based on both CNS and PNS effects, whichever is the more onerous at the frequency concerned, which at 50 Hz is the CNS limit. The reference levels are deliberately set below the field required to produce the basic restriction. ICNIRP say, for example, that the magnetic-field reference levels have an extra factor of 3 built in to allow for "dosimetric uncertainty".
The fields actually required to produce the basic restriction are always higher than the reference levels and need to be derived from dosimetric modelling. We give the best available values in the following tables but there is uncertainty around these values. We discuss the derivation of these values and the alternatives on a separate page.
Occupational exposure:
Basic restriction:
100 mV/m in the head
800 mV/m in the whole body
Magnetic fields
Electric fields
ICNIRP reference level: 1 mT
field actually required: 3.03 mT
ICNIRP reference level: 10 kV/m
field actually required: 24.2 kV/m
These values are for 50 Hz - see here for the values at 60 Hz
Public exposure
Basic restriction:
20 mV/m in the head
400 mV/m in the whole body
Magnetic fields
Electric fields
ICNIRP reference level: 200 µT
field actually required: 606 µT
ICNIRP reference level: 5 kV/m
field actually required: 9.9 kV/m
These values are for 50 Hz - see here for the values at 60 Hz
Chronic effects
ICNIRP state:
"It is the view of ICNIRP that the currently existing scientific evidence that prolonged exposure to low frequency magnetic fields is causally related with an increased risk of childhood leukemia is too weak to form the basis for exposure guidelines. In particular, if the relationship is not causal, then no benefit to health will accrue from reducing exposure."
In the Factsheet they give more detail:
"The absence of established causality is the reason why the epidemiological results have not been addressed in the basic restrictions. ICNIRP is well aware that these epidemiological results have triggered concern within the population in many countries. It is ICNIRP's view, that this concern is best addressed within the national risk management framework. Risk management in general is based on many different aspects, including social, economic, and political issues. ICNIRP in this context provides scientifically based advice only. Additional risk management advice, including considerations on precautionary measures, has been given for example by the World Health Organization and other entities."
Does anyone use these Guidelines?
Most countries who have based their standards on ICNIRP have used, specifically, the 1998 ICNIRP Guidelines. The only countries we know of who have adopted these 2010 Guidelines are Japan and Germany.
