Investigation into the Effects of Applying the Physical Agents (EMF ... · comparison with the revised EMF Directive. In the previous T515 project significan t work, in measurements

Investigation into the Effects of Applying the Physical Agents (EMF) Directive in the UK Railway System

Copyright RAIL SAFETY AND STANDARDS BOARD LTD. 2015 ALL RIGHTS RESERVED

This publication may be reproduced free of charge for research, private study or for internal circulation within an organisation. This is subject to it being reproduced and referenced accurately and not being used in a misleading context. The material must be acknowledged as the copyright of Rail Safety and Standards Board and the title of the publication specified accordingly. For any other use of the material please apply to RSSB's Head of Research and Development for permission. Any additional queries can be directed to [email protected]. This publication can be accessed by authorised audiences, via the SPARK website: www.sparkrail.org.

Written by: Lloyds Register Rail

Published: May 2015

mailto:[email protected]://www.sparkrail.orghttp://www.sparkrail.org

Summary......................................................................... 1

Introduction................................................................... 3Background .......................................................................................................4

Exposure limits and action levels ..................................................................................................6

ELV: Exposure limit value .................................................................................................................6

AL: Action level ...................................................................................................................................7

Methodology ........................................................................................................................................7

Limits .......................................................................................................................................................8

Action level limits for frequencies >1Hz .....................................................................................8

Glossary ........................................................................................................... 11

Abbreviations................................................................................................. 11

Review of T515 .......................................................... 13Task 1 ............................................................................................................... 13

T515 project review ........................................................................................................................ 14

Task 2 ............................................................................................................... 15

Task 3 ............................................................................................................... 17

Lack of railway standard cases ................................................................................................ 18

AC network supply voltage ripple .............................................................................................. 19

DC substation harmonics .............................................................................................................. 20

Task 4 ............................................................................................................... 22

Railway standard case ................................................................................................................ 23

Railway EMF fact sheet ................................................................................................................. 24

Conclusions ................................................................. 25

References ................................................................... 27

Contents

Investigation into the effects of applying the Physical Agents (EMF) Directive in the UK railway system

Summary

The EMF Directive has now been updated and finalised as 2013/35/EU, published by the European Commission on the 29th June 2013. This is to be implemented in UK Law by 1 July 2016.

Research project T1051 has being undertaken to update the deliverables of an earlier project T515 in-line with this new Directive.

The 2013 EMF Directive is similar to the 2004 EMF Directive in terms of limits with a relaxation in some areas and only more stringent values in the electric field limits in the frequency range 1kHz to 1MHz. Furthermore movement in high static intensity fields or very low frequency fields was not considered in the T515 report. The assessment methodology and limits in this area had not been developed at the time. These have now been published by ICNIRP and included in the 2013 Directive (by indirect reference).

The static field limits for pacemakers are given more weight in the 2013 Directive.

The assessment methodology requires an assessment (measurement or calculation) versus the stated action levels unless:

An Assessment has been carried out or the environment has been determined to comply with a more rigorous requirement (Public Recommendation 1999/519/EC).

The equipment is known to comply with the action levels (such as equipment certified to the Low Voltage Directive).

The Situation complies with a Standard Case (likely to be defined in the Guidance document, for example typical office and shop environments).

The work carried out in T515 (modelling and testing) has been reviewed with respect to the new EMF Directive and it is concluded that it remains valid. The particular cases of concern identified have the same or more relaxed limits in the 2013 EMF Directive.

The greatest change in the 2013 EMF Directive is in the process for achieving compliance.

RSSB|InvestigationintotheeffectsofapplyingthePhysicalAgents(EMF)DirectiveintheUKrailwaysystem

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The European Commission will publish non-binding guidance no later than January 2016.

Other industries which have funded research in this area and expressed concerns as to achieving compliance are operating in the following areas:

Mobile telecommunications

Radio systems

Magnetic resonance imaging

Welding

Electrolysis and electroplating

Of relevance to the rail industry are the concerns expressed by The Welding Institute (TWI) with respect to welding, although for most welding associated with the railway (rail to rail) welding machinery is involved which would keep the operator at a safe distance.

Where products fall within the scope of Low Voltage Directive, Machinery Directive, or Radio Equipment Directive they will be assessed for compliance with occupational EMF requirements.


Introduction

In 2004 the European Commission published the Physical Agents (Electromagnetic Fields) Directive (2004/40/EC) (EMF Directive). As a result, RSSB commissioned Lloyds Register Rail to perform research project T515 Investigation into the Effect of the Physical Agents (Electromagnetic Fields) Directive on railway operations, which concluded that EMF levels in day-to-day operations of the rail industry were well below the action levels referred to in the 2004 Directive.

The 2004 Directive has now been updated and finalised as 2013/35/EU, published by the European Commission on the 29th June 2013 to be implemented in UK Law by April 2016. This new version of the Directive is not directly equivalent to the early version and the changes from the previous version 2004/40/EC require consideration.

For this reason, a further research project, T1051, has been undertaken by Lloyds Register Rail to update the deliverables of T515 in line with the new EMF Directive.

This involved:

Task 1 -- A desktop review of the previous work done under T515 and a comparison with the revised EMF Directive.

In the previous T515 project significant work, in measurements and modelling, was carried out to establish the typical levels expected in the Railway environment and a comparison of these fields with the action levels and Reference Levels in the 2004/40/EC Directive. This work has been reviewed to establish compliance with the new limits defined in EMF Directive 2013/35/EU.

Task 2 -- A desktop review of the work done, concerns of other industries and 3rd parties with respect to the new directive.

In the UK the Health & Safety Executive (HSE) has been leading the consultation on this directive and has held several seminars during its period of development. The HSE has also set up a web forum for discussions on the implementation of the EMF Directive http://webcommunities.hse.gov.uk


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http://webcommunities.hse.gov.uk

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Task 3 -- A review of the previous work done under T515 to identify any gaps needing additional studies.

The previous T515 project work has been reviewed to establish gaps with the new methodology defined in EMF Directive 2013/35/EU. The new 2013 directive has changed the definition of limits and included pacemakers and implantable medical device limits.

Task 4 -- Review of T515 work to establish compliance with the new methodology defined in EMF Directive 2013/35/EU.

BackgroundThe EU has issued two Directives on the health and safety implications of occupational exposure to electromagnetic fields. These are:

Directive 2004/40/EC of the European Parliament and of the Council of 29 April 2004 on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (electromagnetic fields).

Directive 2013/35/EU of The European Parliament and Of The Council of 26 June 2013 on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (electromagnetic fields).

In this document they are referred to as the 2004 Directive and the 2013 Directive respectively.

Exposure to electromagnetic fields also applies to the general public; however, neither Directive seeks to control these although the 2013 Directive does state:

In workplaces open to the public it is not necessary for the exposure assessment to be carried out if an evaluation has already been undertaken in accordance with the provisions on the limitation of exposure of the general public to electromagnetic fields, if the restrictions specified in those provisions are respected for workers and if the health and safety risks are excluded.

This implies that there are limits defined for the public that are generally applied.

The two Directives are very similar. In general content the 2013 Directive is more focussed and prescriptive; the 2004 Directive suggested that certain factors should be taken into account whereas the 2013 Directive is more likely to give a prescriptive limit.


The 2013 Directive states that its implementation will define minimum requirements and that each country is allowed to apply more restrictive measures if it thinks these are of benefit to the workforce; the HSE position is that the UK requirements will not be more stringent than the 2013 Directive.

Both Directives state that the assessment must be risk based and depend upon exposure level, exposure pattern and frequency (of exposure).

In order to facilitate the implementation of the 2013 Directive the Commission will make available non-binding practical guides at the latest six months before the implementation date of 1 July 2016.

The Directives distinguish between near field and far field effects giving separate definitions to the electric, magnetic and electromagnetic (radiated) fields. For the purposes of the Directive limits no definitive frequency threshold is given for the transition between separate electric and magnetic and electromagnetic values. Limits are given for electric and magnetic fields covering the whole spectrum up to 300GHz although at frequencies above 6GHz power based Specific Absorption Rate (SAR) level limits are also given.

The effects of non-ionising electromagnetic radiation are considered in more detail in the 2013 Directive.

All effects are biophysical, however, there are several types defined:

direct biophysical effects means effects in the human body directly caused by its presence in an electromagnetic field .

There are three sub-categories of biophysical effect:

Thermal effects; tissue heating through energy absorption from the fields

Non-thermal effects; the stimulation of muscles, nerves or sensory organs. In addition to the gross effect, e.g. phosphenes (optical effects such as flashes of light) and vertigo, the 2013 Directive states that, these can be transient symptoms which may act as a distraction from performing work safely. In addition, it states that these effects may be detrimental to mental as well as physical health

Limb currents; these are currents induced in limb nerve tissue which may activate (involuntary) muscle actions

indirect (biophysical) effects means effects, caused by the presence of an object in an electromagnetic field, which may become the cause of a safety or health hazard:


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There are several sub categories of indirect effect:

Interference with medical electronics; cardiac pacemakers, implants or medical devices worn on the body

Projectile risk from ferromagnetic objects in static magnetic fields

The initiation of electro-explosive devices (detonators); normally this is only of concern to specialist workers

Fires and explosions resulting from the ignition of flammable materials by sparks caused by induced fields, contact currents or spark discharges

Contact currents; currents caused by touching a charged conductor. This is distinguished from the risk of electric shock from exposed conductors which is explicitly excluded from the Directives

Exposure limits and action levels

There are several separate levels and limits defined in the 2013 Directive. These differ in description and, in some instances in value, from those of the 2004 Directive. Moreover, they are categorised in the 2013 Directive into classes dependent on the severity of the exposure. Exposures limits are separated into two main classes.

ELV: Exposure limit value

exposure limit values (ELVs) means values established on the basis of biophysical and biological considerations, in particular on the basis of scientifically well-established short-term and acute direct effects, i.e. thermal effects and electrical stimulation of tissues;

The meaning of an ELV is therefore one where an effect will (probably) occur if someone is exposed. This class is divided into two sub-classes:

health effects ELVs means those ELVs above which workers might be subject to adverse health effects, such as thermal heating or stimulation of nerve and muscle tissue;

sensory effects ELVs means those ELVs above which workers might be subject to transient disturbed sensory perceptions and minor changes in brain functions;

The two sub-categories reflect the difficulty in separating the effects of electromagnetic fields as, whilst health effects are directly verifiable by the appearance of gross physical symptoms, the more subtle changes from


sensory effects (which may be behavioural) would be much more difficult to diagnose.

As ELVs are defined in terms of internal (body) electric field strength they cannot be measured and hence are of little practical use in the application of the 2013 Directive.

AL: Action level

Action Levels (ALs) are practical electric / magnetic field levels that have been defined to simplify the process of demonstrating compliance with the ELVs.

Action levels are separated into High and Low levels that relate to specific protection or prevention measures. The low action level can be exceeded, provided certain precautions are taken and the high action level are not exceeded.

Prevention and protection measures refer to the general concepts under Health & Safety legislation of removing a hazard or using measures such as PPE to reduce the risk of harm.

For electric fields both high and low levels relate to the specific protection or prevention levels.

For magnetic fields high levels relate to health effects and low levels relate to sensory effects.

Methodology

The methodology for demonstrating compliance is risk based and it is the responsibility of the employer to perform the risk assessment. As the subject of EMFs is complex and as the 2013 Directive now has several different limits applied (ELVs and ALs) the actual methodology can be best expressed as a flowchart (see Appendix A). The actual assessment will range from a checkbox paper study to a full program of iterative testing to see if the action levels are exceeded.

The description of the methodology to be used includes measures that are clearly intended for particular workers: medical investigation staff and the military. However, the actual equipment used for each of these groups is not specifically stated. There is an implication that MRI scanning is the intentional target for medical staff. To this end, the methodology includes a special exemption category where exceedance of the action levels (and sensory


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levels) is permitted under certain circumstances. Health levels are understood to be an absolute.

It is not stated whether workers have a right to be given the results but they must be consulted during the process.

Limits

Rather than the single limits given in the 2004 Directive for magnetic and electric fields, the 2013 Directive has several different limits for each and the interpretation of which limit will apply must be determined on a case by case basis.

Limits are given in the appendices of the 2013 Directive for the health and sensory ELVs and for the corresponding action levels. The ELVs are given for fields inside the body and are therefore very specialist and are only needed if the action levels are exceeded. There is no practical way to measure the fields inside the body so this will have to be done by calculation and/or modelling.

Action level limits for frequencies >1Hz

The action levels are measured in the free field i.e. without the body present.

The general (frequency based) limits are illustrated in the charts below, however, there are additional limits that apply for static and very low frequency fields (

9sicalAgents(EMF)DirectiveintheUKrailwaysystem
RSSB|InvestigationintotheeffectsofapplyingthePhy
Figure 1 - Comparison of electric field limits 2013 and 2004

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2004

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Figure 2 - Comparison of magnetic field limits 2013 and

GlossaryDirect biophysical effects: means effects in the human body directly caused by its presence in an electromagnetic field .

Electromagnetic fields: means static electric, static magnetic and time-varying electric, magnetic and electromagnetic fields with frequencies up to 300 GHz.

Indirect (biophysical) effects: means effects, caused by the presence of an object in an electromagnetic field, which may become the cause of a safety or health hazard

Thermal effects: tissue heating through energy absorption from the fields

Non-thermal effects: the stimulation of muscles, nerves or sensory organs. In addition to the gross effect, for example, phosphenes (optical effects such as flashes of light) and vertigo, the 2013 Directive states that, these can be transient symptoms which may act as a distraction from performing work safely. In addition, it states that these effects may be detrimental to mental as well as physical health.

Limb currents: these are currents induced in limb nerve tissue which may activate (involuntary) muscle actions.

AbbreviationsAC Alternating current

AL Action level

AWS Automatic Warning System

DC Direct current

ELV Exposure limit value

EMF Electromagnetic field

HSE Health & Safety Executive

ICNIRP International Committee on Non-Ionising Radiation Protection

MRI Magnetic resonance imaging

PNS Peripheral nervous system

SAR Specific absorption rate

SME Small- and medium-sized enterprise(s)


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T&RS Traction and rolling stock

TPWS Train Protection and Warning System


Review of T515

Task 1The 2013 Directive states that the Commission has the overall responsibility for producing guidelines to aid in the interpretation and use of the action levels and health effect levels given in the technical sections (annexes). It has also given the commitment to deliver this guidance by January 2016.

Whilst it is not impossible to measure fields within the body the 2013 Directive implies that the health effects must be calculated by modelling. The guidance will give an explanation of the rules to be applied to relate measured (free space) levels to Health Effect ELVs within the body. These will include how to apply the calculation/modelling to spatial averages and to allow for uncertainties in the modelling process. It is assumed that this will also define exposure time.

There will be separate guidance on Non-Uniform exposure.

There will be separate guidance on multi-frequency fields: non-sinusoidal fields. This will also define the summation rules to be applied to calculate a cumulative exposure.

The 2013 Directive implies that there will be guidance supplied on what might constitute a standard situation. This is aimed at simplifying an assessment of SMEs who might have a low risk environment (a standard office) and hence would not require further assessment.

There will be guidance on measures to reduce risk; this will involve activities such as reducing exposure, segregating areas, signage, working practices, and training.

There will be specific guidance, rules or working procedures for MRI workers.

Where several action levels associated with a frequency range exist (the low and high ones defined in the general graphs (Figure 1 and Figure 2) there will be guidance on how to apply and interpret the evaluation of thermal and non-thermal effects.


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There will be guidance on health surveillance for workers exposed to fields; this will include the requirement to investigate any reports of effects experienced by workers. From the clauses in the first few articles of the 2013 Directive this would include physical, mental and temporary phenomena.

T515 project review

The T515 project involved measurements (about 2009) and modelling (about 2006) carried out when the 2004 Directive had been published but partially prior to the issue of the standard EN50500 in 2008 (Measurement procedures of magnetic field levels generated by electronic and electrical apparatus in the railway environment with respect to human exposure).

The objective was to establish if the typical railway environments would meet the levels defined in the 2004 Directive.

Modelling looked at a variety of sources and systems (such as AWS and APC magnets, TPWS loops, tuned zones of track circuits, rolling stock traction and motor cables, traction motors, inductors and chokes used in T&RS electric traction equipment, train cabs, traction system faults). The project concluded that these systems would likely to be compatible with the 2004 Directive limits.

In order to validate the modelling work typical railway environments were measured including:

Depots (AC)

Rolling stock (AC/DC)

Stations (AC Mainline)

The significant exposure cases identified were:

The 50Hz electric field level directly under the catenary (say on a walkway in a depot)

50Hz magnetic field close to overhead or feeder cables (such as the transformer feeder cable on AC rolling stock)

In terms of 50Hz electric field the 2013 Directive low action limit is the same as the 2004 Directive limit considered in T515 (10kV/m) and a high action limit is double (20kV/m) meaning that for the particular case considered there is a greater margin.

In terms of 50Hz magnetic field the 2013 Directive low action limit is higher than the 2004 Directive limit considered in T515 (500T) with the low action


limit double (1mT) and the high action limit of 6mT meaning that in this particular case there is also a greater margin.

The area where the limits have been changed in the 2013 Directive is the electric field between 1kHz and 1MHz were the low action levels are less than the 2004 Directive values. In the T515 report, no significant sources of electric fields in this frequency range were identified. Although there are a number of magnetic field sources: TPWS loops, audio frequency track circuits, and induction motor currents; the magnetic field action levels are unchanged.

Movement in high intensity static fields or very low frequency fields was not considered in the T515 report. The methodology and limits in this area had not been developed at the time. These have now been published by ICNIRP and included in the 2013 Directive (by indirect reference).

Task 2The EMF directive may impact upon all employers. There are around 30m people working in the UK, in 4.9m private businesses as well as with government organisations. About 5.7m people work in the public sector. Around 50% of the people working in the private sector work for small- or medium-sized enterprises (SME) of fewer than 250 employees. In the UK there are around 50,000 Chartered Electrical Engineers, but only a small percentage of these are likely to be specialists in dealing with RF, EMC, or EMFs. Thus it is evident that implementation of the directive needs to be achieved without significant use of specialist resources.

In terms of participating and commenting on the occupational exposure limits, significant work has been limited to a few medical and industrial sectors:


Electric arc or resistance welding

Electrolysis or electro-plating

These are industries where they are at risk of exceeding the action levels when an operator is in close proximity to source of high magnetic fields (or high DC 50Hz current sources). They have carried out measurement campaigns, calculation and computer modelling with a view to developing risk assessment techniques together with codes of practice for mitigation.

The MRI industry has focused its work on the unique MRI machines used and so does not have useful read across to the rail industry.


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The work carried out by the The Welding Institute (TWI) on behalf of the welding industry European EMF Weld project may prove useful. At present it is not in the public domain but rail industry organisations may already have access as corporate members of TWI. The type of welding of most concern from the research papers published is manual arc welding and resistance spot welding which are not common in the operational railway. Although arc welding may be used in repair work within depots and workshops, and specialist welding of rails (flash butt welding) using high current is used extensively on the railway.

The Welding Institute is advising its members to assess high risk processes now rather than waiting until the legislation is in effect. The rationale being two-fold; the time taken to carry out the assessment and the requirements for any mitigation or training.

The radio communications industry has kept a close watch on developments. However, as the limits in the radio frequency range are well understood and have been applied in practice for over 20 years this industry has no specific issues. This industry is helped by the fact that from an implementation point of view antenna masts and base stations are at very specific locations.

For the rail industry radio communications systems, such as base stations and mobile GSMR, will be adequately addressed by available standards. The main difference in the rail industry compared to elsewhere being generally lower antenna heights but this is covered by the assessment methodology in the standards.

The Electricity Network Association has prepared guidance and information relating both to the public exposure and occupational limits specified in the ICNIRP 1998 recommendation. Its studies relate to the structure of high voltage 3-phase distribution systems as such they are not directly applicable to the railways.

Where products fall within the scope of Low Voltage Directive, Machinery Directive, or Radio Equipment Directive, they will in the future be assessed for compliance with occupational EMF requirements. However this, in itself, is not likely to be sufficient for rail industry compliance alone due to the bespoke nature of traction power supplies and rolling stock which fall outside the scope of these directives. Nevertheless, it may be useful to include a wide range of areas within the Railway, such as shops, offices, and depot workshops, as typical industry domains within the proposed guidance document being produced by Public Health England.


Task 3The significant exposure cases identified were:

The 50Hz electric field level directly under the catenary (for example on a walkway in a depot)

50Hz magnetic field close to overhead or feeder cables (for example the transformer feeder cable on AC rolling stock, infrastructure fed cables)

In terms of 50Hz electric field, the 2013 Directive low action limit is the same as the 2004 Directive limit considered in T515 (10kV/m); and a high action limit is double (20kV/m) meaning that for the particular case considered there is a greater margin.

Major infrastructure systems such as electrification and signalling, were not within the scope of the T515 project, except at interface boundaries such as stations, as they were assessed independently by Network Rail.

In terms of 50Hz magnetic field the 2013 Directive low action limit (1mT) is double that of the 2004 Directive limit considered in T515 (500T), and the high action limit is 6mT; meaning that in this particular case there is also a greater margin.

It is likely that some areas of electric field exposure on the railway will lie between the low action level and high action level in a few limited circumstances such as described in the previous T515 project. In this case they will need some documentation:

Risk assessment

External documentation

Measurement results (if applicable)

Assessment (if applicable)

Preventative measures to be applied

Protective measures to be applied

Mitigation action plan


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Lack of railway standard cases

Public Health England (PHE) have prepared a guidance document for application of the New EMF Directive under contract to the EU, not currently in the public domain. This document (around 300 pages) is currently being reviewed by the EU. The main focus of the guide is:

The determination of exposure, taking into account appropriate European or international standards

Guidance on demonstrating compliance in special types of non-uniform exposure in specific situations, based on well established calculations and measurements

The description of the weighted peak method for the low frequency fields, and of the multi-frequency fields summation for high frequency fields

The conduct of the risk assessment and, wherever possible, the provision of simplified techniques, taking into account in particular the needs of SMEs

Measures aimed at avoiding or reducing risks, including specific prevention measures depending on the level of exposure and the workplace characteristics

The establishment of documented working procedures, as well as specific information and training measures for workers exposed to electromagnetic fields during MRI- related activities

The evaluation of exposures in the frequency range from 100 kHz to 10 MHz, where both thermal and non-thermal effects are to be considered

The guidance on medical examinations and health surveillance to be provided by the employer

We anticipate that the railway environment will not be included in the standard cases described. Although aspects of the railway will resemble expected standard cases such as shopping centres.


Figure 3 - Hierarchy of Standards

AC network supply voltage ripple

Modern rolling stock using 4-quadrant single phase power converters to achieve low power supply distortion and close to unity power factor utilises switching frequencies around 1kHz to 5kHz. Harmonics of this switching may cause a high frequency supply ripple voltage in the overhead line.

In the frequency range 3 kHz to 10 MHz the Electric Field low action level is 170 V/m and the high action level is 610 V/m.

The electrification standards [EN 50163] define the maximum AC voltage Umax2 as 29kVrms for less than 5mins.

BS EN 50388:2012 10.4 defines acceptance criteria as The overall acceptance criterion for overvoltages and stability is that no peak voltage higher 50kV for 25kV, 50 Hz networks will occur on the contact line in any point of the power supply network with voltage U defined in EN 50163 below or equal to U max2. This value is the peak value of the distorted voltage waveform. On this basis the maximum tolerable additional peak ripple would be 9kV which equates to 6.4kV rms


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If we considered a 5 kV rms ripple at 5 kHz this would equate to ~1 kV/m for a 5 m catenary height. Within the train the metallic structure would effectively shield staff, although composite cabs may need consideration.

Exposure outside the train may not have been effectively assessed as part of T515. The exposure scenario of concern would be time limited, requiring a train in the vicinity, and highest on track, which is an infrequent location for staff (in T515 measurements were made in a depot at crossing points).

The ripple voltage is dependent on the train switching and resonance in the overhead and distributed over the overhead line. The high frequency ripple will be multi-frequency rather than a pure tone.

This is a low exposure risk but would warrant further consideration to determine if it can be discounted.

DC substation harmonics

A DC substation produces harmonic voltages related to the supply frequency, number of rectifier pulses, and dependent on the load current.

Typical harmonic levels for a DC substation supply are relatively low; less than 30V in the case of 3rd rail or 4th rail systems (refer to Appendix A). The highest electric field would exist very close to the supply rail within 100~200mm. Therefore we conclude that the risk of exceeding the electric field limits on DC traction supplies is negligible.

From the review of T515 against the new directive, presented in this review, the following additional work studies are identified for consideration:

1 Definition of a risk assessment process, based on BS EN 50499 with guidelines and supporting information for typical railway environments.

2 Definition and assessment of standard cases (based on PHE Guidance and a BS EN 50499 approach):

a Stations (non-electrified, AC, DC and dual voltage areas)

b Lineside environment (non-electrified, AC, DC and dual voltage areas)

c Depots (non-electrified, AC, DC and dual voltage areas)

d Technical equipment rooms (signalling and telecommunications)

e Feeder or substations (AC/DC) and switching cubicles

f Low voltage equipment rooms and trackside cubicles

g Rolling stock (passenger, freight, and diesel; AC, DC, and dual voltage)


3 Railways fact sheet on Electromagnetic Fields and human health.

4 Assessment of electric fields due to supply ripple in the 25 kV ac supply.

5 Assessment of occupational pacemaker risk in the railway environment: stations, depots and lineside. Safe distance advice for particular hazards (AWS magnets, 3rd rail or 4th rail, DC feeder cables).

6 Contact current assessment; for example maintenance vehicles or road/rail vehicles in transition mode on the 25 kV AC network.

The 2013 Directive has a greater focus on the assessment methodology and it is concluded that the greatest benefit to the industry may be achieved by providing standard guidance to minimise this task, and brief those employers and employees involved.

In particular the generation of standard cases may assist employers in discharging their responsibilities.

The technical limits in the 2013 Directive are mostly unchanged except for the increased emphasis on consideration of workers with active implantable medical devices. The electric field limit in the frequency range 1 kHz to 1MHz is lower than the old directive. It is not envisaged that there are any sources of electric fields in the frequency range 1 kHz to 1 MHz on the DC railway that would exceed these limits. In the case of the AC railway, a further theoretical assessment to determine if this risk can be discounted would be useful if the industry has reliable basic input data.

The static field limits for pacemakers are now given more weight in the 2013 Directive. It requires the consideration of workers who have declared the use of implanted medical devices, if necessary with individual risk assessments, to prevent exposure to excessive fields (>0.5 mT) in accordance with the Directive 89/391/EEC (Implemented by the Management of Health and Safety at Work Regulations 1999, et al).

Thus it is believed additional guidance on sources of static magnetic fields and safe distances may prove useful in this respect.


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Task 4The assessment methodology as detailed 2013/35/EU basically requires an assessment (measurement or calculation) versus the action levels unless;:

The equipment is known to comply with the action levels (such as equipment certified to the Low Voltage Directive, or certified by the manufacturer)

The situation complies with a standard case (likely to be defined in the guidance document, for example typical office or shop environments)

An assessment has been carried out or the environment has been determined to comply with a more rigorous requirement (Public Recommendation 1999/519/EC)

The work carried out in project T515 (modelling and testing) has been reviewed with respect to the 2013 Directive and it is concluded that it remains valid. The particular cases of concern identified have the same or more relaxed limits in 2013 Directive.

In this area cooperation with HSE in the drafting of the legislation and guidance can assist the railway industry by ensuring employers and employees can readily identify those low risk situations which do not require assessment, as well as any medium- or high-risk situation needing detailed assessment or mitigation.

Typical areas that may need further assessment are detailed in Table 1.

Employees with an active implanted medical device, such as a pacemaker, would need to discuss an individual risk assessment with their employer, although they are unlikely to be exposed to fields capable of affecting an active implanted medical device unless you they enter one of the locations detailed in Table 1.


Railway standard case

The public areas of the railway; stations, level crossings (including Radar fitment) and rolling stock should be included in the UK standard case as not requiring assessment due to assumed conformity. RSSB will support HSE in the development of this case.

Unshielded over bridges on the 25kV network, if they exist, may be an exception to this case.

The argument for this is public access to these areas and the generally held position by HSE and PHE that the UK is in compliance with EU Recommendation 1999/519/EC as periodically reported to the European Commission (refer to Appendix B).

Table1Typicalrailwaysituationsrequiringfurtherassessment

LocationPerson at

riskTask

Likelihood of exceedance or

region of exceedance

On GSM-R or radio base station antenna mast or tower

MaintainerClimbing mast directly in front of energised antenna

Unlikely to exceed unless within 1m of antenna face

Within DC substation

Maintainer

Entering operational DC substation working close to high current conductors

Unlikely to exceed unless within 0.3m of high current conductors

Within AC feeder station

Maintainer

Entering operational AC substation working close to high current or voltage conductors

Unlikely to exceed unless within 1m of high current or voltage conductors

Adjacent to electric arc or flash butt welding

Operator

Remaining close to high current carrying cables during electric arc or flash butt welding processes

Unlikely to exceed unless within 1m of weld cables


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Research by RSSB reported in project T515 and this project supports this position.

Railway EMF fact sheet

In cooperation with HSE a Railway EMF fact sheet should be published giving simple advice to Railway workers as to the nature and risks form EMFs and situations with potential to exceed recommended action levels.


Conclusions

The 2013 Directive is substantially similar to the 2004 Directive in terms of limits with a relaxation in some areas and only more prescriptive values in the electric field limits for the frequency range 1kHz to 1MHz.

It is not envisaged that there are any sources of electric fields in the frequency range 1 kHz to 1 MHz on the DC railway that would exceed these limits. In the case of the AC railway, a further theoretical assessment to determine if this risk can be discounted would be useful if the industry has reliable basic input data.

The static field limits for pacemakers is now given more weight in the 2013 Directive requiring the consideration of workers who have declared the use of implanted medical devices, if necessary with individual risk assessments, to prevent exposure to excessive fields (>0.5mT) in accordance with the Directive 89/391/EEC (Implemented by the Management of Health and Safety at Work Regulations 1999, et al). In the UK context this is not a significant change.

The greatest change in the 2013 Directive is in the process for achieving compliance.

The assessment methodology basically requires an assessment (measurement or calculation) versus the action levels unless:

The equipment is known to comply with the action levels (such as equipment certified to the Low Voltage Directive, or certified by the manufacturer)

The situation complies with a standard case (likely to be defined in the guidance document, for example typical office or shop environments)

An assessment has been carried out or the environment has been determined to comply with a more rigorous requirement (Public Recommendation 1999/519/EC)

The work carried out in project T515 (modelling and testing) has been reviewed with respect to the 2013 Directive and it is concluded that it remains valid. The particular cases of concern identified have the same or more relaxed limits in 2013 Directive. Some areas were not considered at the time of the T515 project.


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Movement in high static intensity fields or very low frequency fields was not considered in the T515 report. The methodology and limits in this area had not been developed at the time. These have now been published by ICNIRP and included in the 2013 Directive (by indirect reference).

A number of other organisations have been involved in discussions with HSE and also directly with the EU on the content and structure of the revised EMF Directive.

These organisations are primarily ones with a significant knowledge of electromagnetic fields and involved in these industries:

Mobile telecommunications

Radio systems


Welding

Of most relevance to the rail industry are the concerns expressed by TWI with respect to welding, although for most welding associated with the railway (rail to rail) welding machinery is involved which would keep the operator at a safe distance.

The rail industry can obtain benefit from taking due cognisance of the Risk Assessment approach adopted by TV SD, TWI, MRI Alliance and machinery standards.

Where products fall within the scope of the Low Voltage Directive, Machinery Directive, or Radio Equipment Directiveit should be assessed for compliance with occupational EMF requirements.

In particular the generation of standard cases may assist employers in discharging their responsibilities.

We believe additional guidance on sources of static magnetic fields and safe distances may prove useful in this respect.

The conclusion of this review is that cooperation and communication with HSE in respect of the proposed 2013/35/EU EMF Directive UK Regulations and specific Guidance would be of great benefit to the railway industry in reducing the uncertainty and burden of implementation.


References

1 Electric and magnetic fields the facts, produced by Energy Networks Association - June 2013, http://www.energynetworks.org/modx/assets/files/electricity/she/emfs/EMF_The_Facts_260613.pdf

2 http://www.sagedialogue.org.uk/

3 Power Lines: Demonstrating compliance with EMF public exposure guidelines - A voluntary Code of Practice, March 2012, Department of Energy and Climate Change. https://www.gov.uk/government/publications/demonstrating-compliance-with-emf-public-exposure-guidelines-voluntary-code-of-practice

4 Power Lines: Control of Microshocks and other indirect effects of public exposure to electric fields -- A voluntary Code of Practice, July 2013, Department of Energy and Climate Change. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/224766/powerlines_vcop_microshocks.pdf

5 Occupational Exposure to Electromagnetic Fields at Radio transmitter Sites, HPA-RPD-026, June 2007, ISBN 978-0-85951-596-2

6 Health Effects from Radiofrequency Electromagnetic Fields, report of the independent Advisory Group on Non-ionising Radiation, RC-20, April 2012

7 An Investigation into Occupational Exposure to Electromagnetic Fields for Personnel Working With and Around Medical Magnetic Resonance Imaging Equipment, Project VT/2007/017

8 Are there harmful Biological Effects of Low-Level Electromagnetic Fields at frequencies up to 300 GHz?, 2014 Position Statement provided by the Institution of Engineering and Technology.

9 Institute of Physics and Engineering in Medicine, Policy Statement -- The Role of the Medical Physicist and Clinical Engineer in the use and effects of Electromagnetic Fields in Hospitals.

10workSMART from the TUC, http://www.worksmart.org.uk/health/electromagnetism

11TUV Sud Presentation on the EMF Directive http://www.TV SD .co.uk/uploads/images/1391441747473168070833/pad-emf-peter-dorey.pdf


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http://www.sagedialogue.org.uk/https://www.gov.uk/government/publications/demonstrating-compliance-with-emf-public-exposure-guidelines-voluntary-code-of-practicehttps://www.gov.uk/government/publications/demonstrating-compliance-with-emf-public-exposure-guidelines-voluntary-code-of-practicehttps://www.gov.uk/government/publications/demonstrating-compliance-with-emf-public-exposure-guidelines-voluntary-code-of-practicehttps://www.gov.uk/government/uploads/system/uploads/attachment_data/file/224766/powerlines_vcop_microshocks.pdfhttps://www.gov.uk/government/uploads/system/uploads/attachment_data/file/224766/powerlines_vcop_microshocks.pdfhttps://www.gov.uk/government/uploads/system/uploads/attachment_data/file/224766/powerlines_vcop_microshocks.pdfhttp://www.worksmart.org.uk/health/electromagnetismhttp://www.worksmart.org.uk/health/electromagnetismhttp://www.TV SD .co.uk/uploads/images/1391441747473168070833/pad-emf-peter-dorey.pdfhttp://www.TV SD .co.uk/uploads/images/1391441747473168070833/pad-emf-peter-dorey.pdf

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12 Magnetic Resonance Special Interest Group, MR Safety Update Royal Society of Edinburgh 6 November 2013

13CE Marking Association Human Exposure to EM Fields http://www.cemarkingassociation.co.uk/docs/marketing/EMF-Safety-Guidance.pdf

14Electromagnetic Fields (EMF) in the welding environment, Research Report 1018

15BS EN 12198-1-2009 Safety of machinery Assessment and reduction of risks arising from radiation emitted by machinery Part 1: General principles

16BS EN 12198-2-2009 Safety of machinery Assessment and reduction of risks arising from radiation emitted by machinery Part 2: Radiation emission measurement procedure

17BS EN 12198-3-2009 Safety of machinery Assessment and reduction of risks arising from radiation emitted by machinery Reduction of radiation by attenuation or screening

18Testing 2013/2014 Directory Test Houses & Labs EMC Equipment http://www.compliance-club.com/pdf/TestingDirectory2014.pdf

19T1051 Review of Project T515 with respect to the New EMF Directive 2013/35/EU for RSSB, 29/08/2014, Reference: 272837rep01_Iss01


http://www.cemarkingassociation.co.uk/docs/marketing/EMF-Safety-Guidance.pdfhttp://www.cemarkingassociation.co.uk/docs/marketing/EMF-Safety-Guidance.pdfhttp://www.compliance-club.com/pdf/TestingDirectory2014.pdfhttp://www.compliance-club.com/pdf/TestingDirectory2014.pdf

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SummaryIntroductionBackgroundExposure limits and action levelsELV: Exposure limit valueAL: Action levelMethodologyLimitsAction level limits for frequencies >1Hz

GlossaryAbbreviations

Review of T515Task 1T515 project review

Task 2Task 3Lack of railway standard casesAC network supply voltage rippleDC substation harmonics

Task 4Railway standard caseRailway EMF fact sheet

ConclusionsReferences

Documents

Investigation into the Effects of Applying the Physical Agents (EMF ... · comparison with the revised EMF Directive. In the previous T515 project significan t work, in measurements