Resolution GSC-10/05: (GRSC) Facilitating Liaison in Relation to Measurement

Methodologies for Assessing Human Exposure to RF Energy

Update

SOURCE: ETSI TC Safety

TITLE:

AGENDA ITEM:

CONTACT: Brian Copsey bc@copsey-comms.com

GSC11/ (06)

Physical Agents Directive

• Physical Agents Directive (part 18) 2004/04/EC• the total EMF exposure within a work place both

from the equipment under the control of the employer within that workplace and EMF contributions outside that workplace. i.e. transmitters on adjacent buildings.

– Responsibility now lies with the employer.

ETSI Contribution

• Whilst joint CENELEC- ETSI working groups are producing the standards for the Commission mandate, ETSI ERM TG27 had been working on :

• EG 202-373 Guide to the methods of measurement of Radio Frequency (RF) fields

EG 202-373

• This ETSI Guide is dedicated to the memory of Gerald H David OBE, founder and chairman of the Radio Site Engineering Task Group. His wise counsel and professional approach resulted in a number of practical standards being published to the benefit of the radio community and the wider engineering field.

• The document is a guide to practical methods of measurement that can be used for the assessment of the radiated RF fields at radio sites and other locations where radio signals are encountered.

EG 202-373

• The guide is the first ETSI document to cover the practical measurement of a multi use radio site, and compares a range of probes measuring the same EMF field

EG 202-373

• The results of the tests indicated a high degree of confidence using 3 different manufacturers equipment, which gave results where the differences were not significant for radiated RF field measurements and therefore could be used in the assessment of locations at which it is necessary to measure the presence of RF fields at specific levels.

• It is important to note that the tests carried out only involved individual frequencies. Further work is needed to determine the situation in a multi-frequency environment.

EG 202-373

• The issues of multi frequency measurements and calibration are the subject of ongoing work by TG27 in collaboration with the UK National Physics Laboratory

EG 202-373The Site Measured

Towers on Site

Conclusion

– The measured results have been related to current standards relating to human exposure to electromagnetic fields. Specifically:

– ICNIRP International Committee on Non-Ionizing Radiation Protection;

– Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic and Electromagnetic Fields (up to300 GHz).

– From the tables in the guide it can be seen that the maximum signal level recorded is 40% of the ICNIRP reference level for general public exposure.

– It can thus be stated that the site is compliant with current RF hazard regulations.

CENELEC-ETSIJoint WP4

• Documents produced under the mandate are probably for the first time in EMF standards work aimed at the employer or other non technical personal.

• The Standard draws together existing Standards, guides and other documents with flow charts and tables to lead the reader through the process.

Zoning

• This describes a simple administrative procedure that employers may wish to consider in order to define different areas in their workplace.

• These are not intended to be strict or “hard” boundaries corresponding to the exact locations that different exposure levels might be exceeded. Instead they might correspond to, for example, existing areas of a workplace. For example, a particular building or area might contain equipment that gives rise to exposures greater than public levels, even though those levels are not exceeded in most of the building or area. The employer may choose, for reasons of convenience, that access to that whole building or area should be restricted to certain people (eg excludes visiting members of the public) or that access is associated with information about likely EMF levels.

• Various zones are defined, but whether and where the exact zone boundaries are decided is a matter for the individual employer. What actions (if any) are to be taken at zone boundaries also is a matter for the employer.

– Workplace zones• A Zone 0 workplace is one in which all exposure levels are complying with the relevant general

public limits. • In Zone 1, exposures may be greater than the general public limit but will be compliant with the

occupational exposure limit. • In Zone 2, exposures may be greater than the occupational exposure limit. If access is possible

to Zone 2, then remedial measures to reduce exposure or to restrict or limit access should be taken.

Assessment

• In assessing the workplace the employer is encouraged to use the following flow chart. Table 1 assists the process by a list of common devices:– Not considered to produce EMF over the

limits,

or– Where further investigation is necessary.

ActionValuesmet ?

Specificworkplacestandard?

In complianceWith table 1?

ExposureLimitsMet ?

Assessment against Action Values (clause 8)

Assessment against Exposure Limits

(Clause 9)

Measures[Clause 10]

Assessmentvia that

standard

End of assessmentSee annexe B

Start of assessment

Procedures from other (basic, generic, product)

standards

No

No

No

No

Yes

Yes

Yes

Yes

Future

• Work continues in various committees which will be either referenced or included in the final Standard.