Magnets, RF, EMF

Scope

This experimental work instruction applies to the use of Magnets, Radio Frequency equipment and Electromagnetic Fields where these are above the Action Levels (ALs) or Exposure Limit Values (ELVs).

See Appendix 1 for further information.

 

Pre-visit

User Principal Investigator shall provide the following to the Diamond Local Contact at least eight weeks prior to the experiment at Diamond:

• Essential Information Requirements (see below).

Assurances that User-provided equipment achieves the relevant:

• Essential Safety Requirements (see below).

Assurances that Users coming to Diamond achieve the relevant:

• Essential Competency Requirements (see below).

Assurances that the equipment is compliant with the safety requirements of the home institution.

Diamond Local Contact shall ensure compliance with the following for Diamond provided equipment:

• Essential Information Requirements (see below);
• Essential Safety Requirements (see below);
• Essential Competency Requirements (see below).

 

Pre-experiment

Diamond Local Contact shall ensure that the above pre-visit requirements for User provided equipment is reviewed by a competent mechanical technician or engineer.  This shall include inspection of the equipment.

 

Experimental Setup

Diamond Local Contact & User Visit Principal Investigator shall collaborate to ensure adherence to:

• Essential Experimental Setup Checklist (see below).

 

Operation

Diamond Local Contact & User Visit Principal Investigator shall collaborate to ensure adherence to:

• Essential Operational Checklist (see below).

 

Essential Safety Requirements

Equipment shall be:

• Rated and compatible for the intended fields, frequencies, and voltages / currents;
• Suitably tested by a competent person or body to ensure safe operation at Diamond.  Non-standard set-ups shall be commissioned and tested prior to coming to Diamond;
• Safely packaged & transported to Diamond to prevent damage that could affect safe operation;
• Suitably risk assessed, identifying failure modes, safety controls and emergency controls (ref Essential Hazard & Failure Mode Checklist);
• Fitted with suitable safety devices (e.g., remote emergency shutdown);
• Electrical conductors within, and supplying the equipment are covered / double insulated and there is no potential for accidental contact;
• Labelling: Equipment CE / UKCA marked or has an appropriate declaration of conformity; and
• Remote operation enabled as far as possible.

 

 

Essential Information Requirements

Information required:

• A full description of the proposed experimental setup & technical specifications.
• Equipment details including hazards, energies, extent to which fields will extend, safety devices.
• Sample environment details including field strengths, shielding requirements, frequencies, and voltages / currents in use.
• Safe distance for persons wearing pacemakers and other medical devices (i.e., 5 gauss line).
• Safe operating procedure / instructions for any equipment not provided by Diamond.
• Unique Identification mark of any equipment not provided by Diamond, i.e., its serial number.  
• Manufacturing QA documents.
• Assurances and evidence that all equipment has full up-to-date test and calibration certificates (where applicable).

 

Essential Competency Requirements

Person setting up experimental equipment shall:

• Have sufficient experience of setup, test and operation of the equipment, risks and required safety controls to ensure safe setup;
• Have sufficient skills and be practiced in the setup and operation of the equipment, risks and required safety controls used in the experiment; and
• Have sufficient knowledge of the essential safety requirements of the equipment to ensure safe setup.

Persons operating equipment shall:

• Have sufficient experience and be practiced in safe use of the specific equipment, risks and required safety controls to ensure safe operation;
• Have sufficient skills and be practiced in safe use of the specific equipment, risks and required safety controls used in the experiment;
• Have sufficient knowledge of the essential equipment safety requirements, risks, and safety controls to ensure safe operation. This includes knowing when to stop operations and what to do in the case of an emergency; and
• Be suitably supervised if they do not have sufficient skills, knowledge, and experience.

 

Essential Experimental Setup Checklist

• Persons setting up the equipment meet the Essential Competency Requirements.
• Metal tools and potential metallic projectiles are eliminated from area with high EMF. 
• Guarding: Components which could fragment due to unintended impact when under strong fields are sufficiently guarded. 
• Appropriate shielding and / or distance has been selected and placed between the hazard and all those who may be affected by the field.
• Electrical conductors where external to equipment are protected from accidental contact.
• Electromagnetic Field (static and moving): The extent of the field is known and marked, and briefed to people at particular risk, e.g., those fitted with medical implants or body-worn medical devices.
• Protective devices are in place and appropriate for the duties of the equipment – consider voltages and current when examining RCD, MCBs, fuses etc.
• Electrical safety devices are in place (e.g., emergency stop) and confirmed as functional.
• Remote shutdown is enabled for all experimental equipment. 
• Signage is sufficient to warn persons with medical devices not to enter areas with high EMF.
• Visual inspection of the setup.
• Manufacturer’s instructions (where applicable) have been followed during setting up.
• Modifications from planned setup have been checked by a competent person.

 

Essential Operation Checklist

• Persons operating the equipment meet the Essential Competency Requirements.
• Visual check of the setup is carried out before every operation.
• Modifications to the planned setup are done by a competent person and checked against the Essential Experimental Setup Checklist.
• Safety controls stated in the User Experimental Risk Assessment (ERA) are applied, and the ERA has been graded and validated.
• Safety controls stated in both the beamline risk assessment and any Diamond equipment risk assessment are applied. 
• Lone-working prohibition is in place and understood by all persons supervising the experiment.
• Suitable manning to ensure a suitable level of manning on the beamline.
• Suitable supervision of the experiment is in place to ensure safety.
• Failure modes of the set-up are understood by all persons supervising the experiment.
• Interlocking of the systems in use has been applied and has been tested.
• High field strength: All persons are aware of field strengths and limits, as well as operating times.  Persons at particular risk have been identified and notified.
• Appropriate warning signs have been placed at entrances to the hazardous areas.
• PPE identified on the risk assessment is provided, it fits, it is in good condition, and all operators are proficient in its correct usage.
• Emergency conditions and required action is understood by all persons supervising the experiment.
• Emergency actions on equipment failure, uncontrolled physical movement due to (stray) fields or localised heating is understood by all persons supervising the experiment.
• Emergency action on the fire alarm sounding is understood by all persons supervising the experiment.
• Emergency action on gas detection (e.g., LN2 for cooling) sounding is understood by all persons supervising the experiment.
• Emergency action on power outage is understood by all persons supervising the experiment.
• If safety issues are identified, the Principal Beamline Scientist (PBS) must be contacted, and the issues resolved before continuing with the experiment.

 

Essential Hazard & Failure Mode Checklist

The main hazards are:

• Crush or impact from uncontrolled release of components or equipment causing physical crush (attraction) or impact (repulsion) injuries;
• Stray fields extending beyond expected distances;
• Unexpected field interaction with electrical / electronic / mechanical equipment;
• Localized heating of body parts / whole body exposure;
• Fire resulting from ignition of flammable materials due to overheating of e.g., electromagnetic coils or power supplies;
• Fire resulting from ignition of flammable materials due to overheating from radiated energy;
• Hot surface contact;
• High voltage / current electrocution from contact with energized circuit; and
• High voltage / current burns from contact with energized circuit.

Principal failure modes are:

• Poor equipment and / or system design;
• Poor installation / setup;
• Poor maintenance of equipment;
• Inadequate repairs or modifications;
• An unsafe system of work; and
• Operator error, poor training / supervision.

 

Appendix 1: Action Levels & Exposure Limit Values summary tables

Table 1: Summary of Action Levels (ALs)

Frequency range	Electric field strength V / m	Magnetic field strength (µT)
1 – 8 Hz	10000	40000 / f2
8 – 25 Hz	10000	5000 / f
25 – 400 Hz	2.5x105 / f	200
400 – 3000 Hz	2.5x105 / f	80000 / f
3 – 100 kHz	83	27
100 – 1000 kHz	85	4.0x107 f1.234
1 – 10 MHz	87000 / f1/2	4.0x107 f1.234
10 – 400 MHz	28	0.092
400 – 2000 MHz	1.375x10-3 f1/2	4.6x10-6 f1/2
2 – 300 GHz	61	0.20

 

Table 2: Summary of Exposure Limit Values (ELVs)

Frequency range	Electric field strength V / m	Magnetic field strength (µT)
1 – 50 Hz	20000	3x105 f
50 – 1640 Hz	1x106 / f	3x105 f
1640 – 3000 Hz	610	3x105 f
3 – 100 kHz	610	100
100 kHz – 10MHz	1.93x105/ f1/2	5.56x108 f1.349
10 – 400 MHz	61	0.20
400 – 2000 MHz	3x10-3 f1/2	1x10-5 /f1/2
2 – 300 GHz	137	0.45

 

Table 3: Summary of limits for Static Electromagnetic fields

Static field strength	Actions required
>0.5mT (5 Gauss)	General risk assessment to be completed Give information on the risks to those affected Display warning signs
>0.1T (1000 Gauss)	Complete an EMF risk assessment Develop and implement local rules f Ensure those affected by the EMF are trained and given suitable information Display warning signs where the field extent is a hazard