SC39 - Static magnetic fields
17 Jun 2011
Yes
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Working with Static magnetic fields

No

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Contents

Revisions

1
Initial launch
March 2011
1.1Amendments to au​dit checklistMay 2013
1.2
Add Document Retention Policy Appendix
August 2014
2.0
Updated to comply with European Directive 2013/35/EU and HSE Consultation Document CD276 and audit findings.

November 2016 

​2.1
​Minor changes to reflect the launch of SHE Assure
​October 2018

NB - The changes to version 2.0 were considerable and readers should assume that significant portions of the body and Appendix 1 have changed.

1. Purpose

Static magnetic fields are used in a range of applications across the STFC sites, for example superconducting magnets in ISIS sample environments, or the permanent magnets in particle physics experiments and accelerator wigglers or undulators. The code aims to minimise so far as is reasonably practicable, the health and safety risks to staff and other persons who may be affected by static magnetic fields.

People can experience vertigo and other physiological effects relating to balance when they move within a strong static magnetic field but the main hazards to people associated with such fields comes from their impact on implanted medical devices (specifically magnetic or electronic devices such as heart pacemakers), and their ability to attract magnetisable objects at distance and speed (projectile and crush incidents), see Appendix 1.

This code was originally written to comply with The European Physical Agents (Electromagnetic Fields) Directive (2004/40/EC amended 2008/46/EC). On June 29th, 2013, the European Commission repealed Directive 2004/40/EC and published Directive 2013/35/EU on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (electromagnetic fields) which includes static magnetic fields.

2. Scope

This code is applicable to all staff, contractors, users and tenants working with strong static magnetic fields at STFC sites.

This code applies to all static magnetic fields (from 0 to 1Hz) which extend into areas readily accessible to people, and applies to all such fields on all STFC sites irrespective of ownership of the apparatus generating the fields.

This code is not intended to cover every piece of equipment in which magnetic fields are present.  For example, the code is not intended to apply to electric motors, loudspeakers and magnetrons in normal use.  However, if strong magnets from such pieces of equipment were removed and made into an assembly for some new purpose generating a magnetic field extending into areas readily accessible to people then this code would apply.

This code does not address the hazards associated with time varying electro-magnetic fields, see STFC SHE Code 23: Working with time-varying EMFs.

3. Responsibilities

3.1 Managers responsible for sources of static magnetic fields >0.5mT that extend into the working environment shall:
  • 3.1.1 Ensure that documented Risk Assessments address the hazards from static magnetic fields, see Appendix 1, SHE code 6 Risk Management. Such risk assessments must be undertaken by individuals with sufficient expertise in such hazards (see Appendix 1), and must be based upon an assessment of the magnetic field, derived as appropriate from: field calculations; from manufacturer’s guidance; or from a site survey of the field contours using a calibrated gaussmeter.
  •  
  • 3.1.2 Locate warning signs at all entrances to areas containing magnetic fields with strengths greater than 0.5mT (5 Gauss), see Appendix 1a
3.2 Managers responsible for sources of strong static magnetic fields, >0.1T, that extend into the working environment shall:
  • 3.2.1 Ensure that documented Risk Assessments address the hazards from strong static magnetic fields, see SHE code 6 - Risk Management: Appendix 1. Such risk assessments must be undertaken by individuals with sufficient expertise in such hazards (see appendix 1), and based upon an assessment of the magnetic field based as appropriate on: field calculations; manufacturer’s guidance; or from a site survey of the field contours using a calibrated gauss meter.

    The magnetic field hazards arising from the quenching of super conducting static magnet fields should always be subject to a risk assessment alongside related hazards such as asphyxiation from escaping cryogens.
  •  
  • 3.2.2 Develop and implement local procedures for the safe operation of equipment generating the static magnetic fields, see Appendix 1.

  • 3.2.3 Ensure that only sufficiently competent people are authorised to operate equipment and work in the areas where strong static magnetic fields are present, and that they are aware of the hazards, risk assessments and local procedures for the safe operation of equipment generating static magnetic fields.

  • 3.2.4 Ensure that warning signs and other measures, e.g. barriers or floor marks, are set up around areas where hazards arising from static magnetic fields could exist. The barriers, or floor marks, should define a zone outside which the magnetic field is less than 3mT (<30 Gauss) in order to delineate the boundary where magnetisable materials such as tools may be accelerated and present projectile hazards, see Appendix 1a.
3.3 STFC Staff, visitors, facility users, tenants and contractors shall:
  • 3.3.1 Comply with the local procedures for the safe operation of equipment which is capable of generating strong static magnetic fields.

  • 3.3.2 Ensure, if any one of them has an implanted medical device such as a heart pacemaker, that he or she informs his or her manager or other person responsible for his or her safety before entering an area where static magnetic fields greater than 0.5 mT (5 gauss) are present in the working environment. Anyone with an implanted medical device may wish to contact Occupational Health or the SHE Group for advice on the likely sensitivity of the implanted medical device to magnetic fields.

  • 3.3.3 Report all incidents relating to strong static magnetic fields through SHE Assure following SHE Code 5 - Incident Reporting and Investigation.​

4. References


Contact: Baker, Gareth (STFC,DL,CSD)