Information for those working with Sources of Non-ionising Radiation
The Technical Advisor in Non-ionising Radiation Safety is
Katharine Sullivan
Tel:
56985
Email: katharine.sullivan@manchester.ac.uk
Please click on the links below to go directly to information on the following:
University Code of Practice and Guidance on Non-Ionising Radiation Safety
Microwaves (including microwave ovens)
Electromagnetic Fields (EMFs)
Training (UV Safe Practice)
Resources for download
Registration form for UV sources
Registration form for Microwave sources
Advice for UV Equipment users (may be printed and laminated for lab use)
UV light is potentially very harmful to exposed eyes and skin. There are both short term effects; serious damage to the cornea (photokeratitis) and to the skin (erythema) and long term effects; skin ageing and cataracts. Different wavelengths of UV light and intensity of source output considerably alter the time required before serious injury occurs. All UV light exposure should be kept to a minimum. A few seconds exposure may be sufficient to cause serious eye damage which may not be felt for several hours and be very painful.
All UV emitting equipment (100-400nm) or that which is suspected to fall in this range MUST be registered with the Radiation Safety Unit. Please download the UV registration form , complete it for all UV sources in your lab and return to Katharine.sullivan@manchester.ac.uk This includes but is not limited to:
- Transilluminators
- Sterilising equipment
- TLC viewing cabinets
- Cadmium/mercury lamps
- Hand held UV lamps
- Phospholuminescence equipment
- Fly killing tubes (Insectocutors)
Example risk assessments
use of transilluminators
housed UV light sources
These are available for you to use. If you have all the listed controls in place then the risk is adequately controlled and they can be used as provided. If not you must modify, stating the controls you do use and re evauate the risk as it may change. When you are satisfied that your measures adequately control the risk, remove the watermark (go to Format, Background, Printed Watermark, and select No Watermark).
To ensure safe UV usage, The Radiation Safety Unit implements the following measures:
Annual survey of all UV emitting equipment
Please contact katharine.sullivan@manchester.ac.ukext 56985 to arrange a survey of your equipment.
This is a requirement for all users of UV equipment on and off campus.
UV safety awareness training is available for small groups throughout the year on request. This is aimed at working in the lab environment where UV equipment is used.
The training comprises of a short presentation followed by a discussion on UV safety.
If working in:
Smith Building - please contact Vikki Kelly
MIB - contact Steve Marsden
Physics - contact Jon Mossman
or contact the Katharine Sullivan at the Radiation Safety Unit.
UV warning signs
These must be clearly visible on the equipment and, where necessary, the lab door/ wall.
PPE (Personal Protective Equipment)
Prevention of exposure during use of UV light requires the use of a full face shield that conforms to BS EN 170. Ordinary laboratory splash spectacles do not absorb UV and should never be used to protect the eyes during UV exposure.
The Radiation Safety Unit labels all face shields that are suitable to protect against UV 'SUITABLE FOR UV PROTECTION'
Those that are NOT LABELLED are NOT SUITABLE and must not be used.
Action to be taken in the event of accidental exposure or injury.
You may not be aware of an overexposure or may have witnessed another person's
- Immediately turn off the source and move away from it.
- Inform your project supervisor what has happened. If you have removed your visor whilst working with a transilluminator, you may not yet be suffering from photokeratitis or necessarily experiencing any pain.
- Seek medical advice. You should attend your local Accident & Emergency Department (and that this will probably be around 12 hours after your exposure when the eyes feel painful 'sand in the eye' sensation.)
- You must complete an Accident Report Form which should be given to your School Safety Advisor to forward to Health & Safety Services.
For all queries relating to UV and appropriate PPE contact katharine.sullivan@manchester.ac.uk
Microwaves (including microwave ovens)
The Radiation Safety Unit will test any microwaves for leakage upon request.
At present, the safe limit for leakage is 5mW/cm2. Any oven with a defective or loose seal or door grid should be reported for testing.
Although some work with microwave transmission is conducted in the Department of Electrical Engineering and Electronics and in the School of Physics and Astronomy, the main use of microwave radiation within the University is in microwave ovens.
All microwave ovens, whether used for heating in experiments such as agar solutions or for domestic cooking, should be registered with the Radiation Safety Unit using the Microwave Oven registration form
The information required is:
• School/Directorate
• Location
• Model
• Serial Number
• Person responsible for the oven
This information may also be sent as an e-mail attachment to katharine.sullivan@manchester.ac.uk
The public safety or otherwise of mobile phone usage, is still under debate and at the early stages of research. Both base stations and handsets work by transmitting and receiving radio waves (mobile phone frequencies lie at the border between radio waves and microwaves). Specific Absorption Rate (SAR) levels are suggested at 2W kg-1 to protect the user from localised heating effects under ICNIRP guidelines, although these have been criticised as inadequate, and relate to a 6 minute exposure. The non-thermal effects are unclear and not advised upon at present as the long term effects cannot be known.
It is therefore the responsibility of the individual to monitor one's own usage. The University does not as yet have a policy regarding mobile phones issued to staff for work purposes. The advice of the NRPB's recent report (2004) is to minimise usage, especially in youngsters.
There are many types of WiFi or WLAN but all of them allow two or more computers to form a network using radio frequency (RF) signals . As in the case of mobile phones, the safety of WiFi is still under great debate. The research is still at early stages. The Health Protection Agency consider there is no consistent evidence of harm from the low power transmissions of WiFi equipment nevertheless its states that it is a sensible precaution to keep the situation under review. The frequencies that WiFi uses are broadly the same as those from other RF applications such as FM radio, TV and mobile phones. The signals from WiFi are very low power, typically 0.1 watt (100milliwatts) in both the computer and the mast (or router) and resulting exposures should be well within internationally accepted guidelines.
For further information please see:
http://www.hpa.org.uk/default.htm
Restrictions on the effects of exposure to EMFs are based upon established health effects and are termed basic restrictions. Depending on the frequency, the physical quantities used to specify the basic restrictions to occupational exposure are as follows:
Time varying electric and magnetic fields
- Between 1 Hz and 10 MHz, basic restrictions are provided on Current density to prevent effects on nervous system functions;
- Between 100 kHz and 10 GHz, basic restrictions on Specific Absorption
Rate (SAR) are provided. This quantity is a measure of how
much heat is deposited in body tissues. SAR levels are applied to
a) prevent whole body heat stress and
b) prevent excessive localised tissue heating; at 0.4W/kg and 10W/kg respectively: - in the 100kHz-10 MHz range, restrictions are provided on both Current density at f/100 (f in kHz) and SAR as above; and
- Between 10 and 300GHz, basic restrictions are provided on Power density to prevent excessive heating in tissue at or near the body surface. This is restricted to 100 W/m 2 .
Visit Health Protection Agency website (old NRPB) at http://www.hpa.org.uk/radiation/understand/at_a_glance/index.htm
Static magnetic fields
There are few sources of high magnetic field strength on campus. If you are near or work with such a source, it is likely you are aware of its presence. However, those working in close proximity to such a source may arrange for a survey especially if they have any health concerns regarding their exposure. For static magnetic fields, occupational exposure should not exceed the time weighted average for 8 hours of 200 mT. Occupational whole-body exposure should not exceed a magnetic flux density ceiling value of 2T. For limbs only, exposures of 5T can be permitted.
Those fitted with a cardiac pacemaker or ferromagnetic implants should be aware that magnetic fields may not be protected by these limits. The majority of cardiac pacemakers are unlikely to be affected by fields <0.5 mT. Above this threshold, such locations should be avoided.
Areas with magnetic flux densities >3mT should specify with a warning sign to prevent movement or dislodgement of ferromagnetic implants, or hazards from flying metal objects.
Further information
For any advice relating to any Non-Ionising radiation use, contact the Radiation Safety Unit on 0161 275 6985
Other Websites
http://www.icnirp.de International Commission Non Ionising Radiation Protection
http://www.hpa.org.uk/radiation/services/nir/ Health Protection Agency UK
http://www.who.int/topics/radiation_non_ionizing/en/ World Health Organisation
Ref: ICNIRP publication Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic fields (up to 300 GHz) : Health Physics Vol. 74, No 4, pp 494-522, 1998.
ICNIRP publication Guidelines on Limits of Exposure to Static Magnetic Fields, Health Physics Vol. 66, No 1 , pp 100-106, 1994.
Last updated 16th August 2007