Interim Australian/New Zealand RF standa

[Andrew McEwan <Andrew@nrl.moh.govt.nz>]

At 08:27 A 22.4.98 -0700, Randy Ross wrote:
>
>
>Richard Smart wrote:
>
>> Dear ARPS Members,
>>
>> In case you missed it, Standards Australia has just published AS/NZS
2772.1 (Int): 1998 Radiofrequency fields part 1: Maximum exposure levels -
3 kHz to 300 GHz.
>>
>> The standard costs $36.50 or $29.20 if your organisation is a member of
Standards Australia.
>>
>
> Is this not to be confused with ICNIRP Guidelines published in Heath
Physics vol74, No4 April 1998?
>
HERE IS A BRIEF REVIEW

After several years of committee meetings and public comment an interim 
revised standard which replaces NZS 6609.1:1990 and AS 2772.1-1990, 
Radiofrequency radiation, Part 1: Maximum exposure levels - 100 kHz to 300 
GHz was published on 5 March 1998. The interim standard is a compromise 
document which broadly follows the 1988 guidelines of the Non-Ionizing 
Radiation Committee of the International Radiation Protection Association, 
and standards in other countries.  For the spectral range above about 10 MHz 
where thermal effects dominate, the basic limit of a specific absorption 
rate (SAR) of 0.4 W/kg for occupationally exposed persons has been retained, 
with the same derived limits as in the earlier Australian and New Zealand 
standards.  For frequencies around 1 MHz, however, the derived limits have 
been made more restrictive in line with those of the IRPA guidelines.  For 
frequencies above 400 MHz where other standards introduce a change in 
derived limits, corresponding to changes in SAR per incident unit power flux 
density, the interim standard retains frequency independent derived limits 
as previously, thus effectively incorporating a safety factor which is 
increasing with frequency.

The frequency range covered by the standard extends now down to 3 kHz. 
 Derived limits at low frequencies have been obtained by adopting the IRPA 
values for 100 kHz for the 3-100 kHz range, and this has created an anomaly 
in magnetic field limits at low frequencies.  Further changes from the 
earlier standard are the introduction of spatial averaging over a 30x30 cm 
area for field measurements, and much more detailed specification of 
requirements for compliance of mobile and portable transmitting equipment. 
 A further change is the disappearance of the ALARA (as low as reasonably 
achievable) requirement from the new standard as an inappropriate for an 
agent which has a threshold for effects.  A 'prudent avoidance' related type 
of statement has instead been incorporated.

The Standards organisations are inviting comments on the interim standard by 
5 March 1999, at which time, or earlier, the interim standard will be 
confirmed, withdrawn or revised.  Perhaps, in view of the difficulties in 
producing a revised local standard, adoption of the revised guidelines of 
the International Commission on Non-Ionizing Radiation Protection (published 
inthe April issue of Health Physics) would be the preferable forward 
direction.


_________________________
Andrew C McEwan PhD
National Radiation Laboratory
PO Box 25-099
Christchurch, New Zealand

Ph 64 3 366 5059
Fax 64 3 366 1156
acmcewan@nrl.moh.govt.nz
________________________