Exposure limits from organisations
A number of organisations have published specific EMF exposure limits, some of which have been adopted by various countries and authorities to form their national or local guidance on EMFs.
Some organisations producing guidelines are:
- International Commission on Non-Ionizing Radiation Protection (ICNIRP).
- International Commission on Electromagnetic Safety (ICES) from the IEEE.
- American Conference of Government Industrial Hygienists (ACGIH) – Occupational.
The guidelines in force in the UK are those of ICNIRP which are described below.
ICNIRP
ICNIRP has developed exposure limits covering low frequency EMFs. Importantly, its guidelines are not intended to be a complete system for protecting the public that should be applied as it stands. ICNIRP says that its guidance considers only the science, and governments will need to consider other factors before deciding whether, and how, to implement the guidelines. Thus, for example, the EU Recommendation references the ICNIRP exposure limits but expects them to be applied only where the time of exposure is significant.
Why are the basic restriction values different between 1998 and 2010?
In the 1998 guidelines the basic restriction is set to limit the induced current, measured in mA/m, but in ICNIRP 2010 they are set to limit the induced voltage, measured in mV/m. Both units essentially limit the same thing and have been set to prevent effects on nerves from occurring.
Why do the ICNIRP 1998 guidelines still apply to public exposures?
Although the ICNIRP 2010 guidelines are the most recent guidelines to be published covering 50 Hz, the Government advice and policy is to apply the 1998 guidance.
The new guidelines will not apply in the UK unless the Government make a specific decision to introduce them. The ICNIRP 2010 limits allow for higher public exposures, so continuing to follow the ICNIRP 1998 guidelines ensures lower public limits are applied.