NEW RADIATION LEGISLATION M M TREVOR
RADIATION Aims to: • Produce a working definition for the term Radiation • Consider what types of radiation are present in the workplace • Look at risk assessment of artificial optical radiation and electromagnetic radiation • Discuss possible implications of the draft IRR 2018
WHAT IS RADIATION?
RADIATION Tasks set in audience’s PowerPoint • Please list what types of energy sources you think we need to consider. • For each energy source you identified please give its method of energy transfer. • Please identify if you would consider potential energy transfer to be radiation. • Have a stab at a definition.
RADIATION Radiation – the transfer of energy from a source This is far too simple a definition we need to consider: • Types of energy • Types of transfer Radiation radiates: • Obeys the Invers Square Law (ISL) rule
RADIATION Energy • We have an energy source such as a hot object (heat), a loud speaker (sound) or a candle (light) • This energy is transferred from the source to another point usually as a wave – Note for heat we consider radiation transfer not conduction or convection
RADIATION Energy • We have an energy source such as an unstable nucleus • E = mc 2 • This radiation is in the form of charged particles (alpha and beta) and un- charged particles (neutrons) • Energy emitted is sufficiently large to ionize an atom
RADIATION Energy transfer • Energy travels from the source in straight lines – rectilinear propagation • It continues to do this until acted upon by an external factor – For example alpha particles are quickly acted upon by the earths gravitational field – this would not happen in outer space
RADIATION Potential Energy – Potential energy being the energy of a body as a result of its position • For example an electric, magnetic or gravitational potential energy – Force is a method to transfer energy – Energy is transferred to the object which the force is acted upon [gives motion KE]
RADIATION Concept of a Field • The field due to a ‘body’ (mass, charge or magnet) is the region of space surrounding the ‘body’ where other ‘bodies’ will feel a force due to it’s presence – Movement in a field changes the potential energy of a body – So energy has been transferred
RADIATION Field lines – We can try to model the field using field lines or lines of force – Gives the direction another body will move under the influence of the force – Field lines have three possible arrangements (as seen with gravitational, electric and magnetic fields)
RADIATION http://hyperphysics.phy-astr.gsu.edu/hbase/Forces/isq.html
RADIATION We do not have magnetic dipoles however the strength of the force does obey the invers square law
RADIATION Definition: Radiation is the transfer of energy (including potential energy) from a (point) source outward such that it obeys the inverse square law (until an interaction takes place), where the energy is transferred as a wave, a particle or the repositioning of a ‘body’ within a field – When energy is radiated from the source, energy is transferred from the source to another point
RADIATION IN THE WORKPLACE • Gravitational field (working at heights) • Sound (noise) • Electric and magnetic fields 2016 • Electromagnetic radiation – Radio waves – Micro waves – Visible radiation 2010 – Ionizing radiation draft for 2018
THE ICNIRP
ICNIRP International Commission on Non-ionizing Radiation Protection. An independent organization, providing scientific advice and guidance on the health and environmental effects of non-ionizing radiation (NIR) to protect people and the environment from detrimental NIR • Investigate the effect of non-ionizing radiation on the body for the different frequencies at http://www.icnirp.org/
CONTROL OF AOR AT WORK REGULATIONS 2010
OPTICAL RADIATION Light is an everyday example of optical radiation (artificial optical radiation, if it is emitted by a lamp and not the sun). • The term ‘optical radiation’ is used because light is a form of electromagnetic radiation, and because it has effects on the eye — i.e. it enters the eye, is focused and then detected.
OPTICAL RADIATION Task set in audience’s PowerPoint • Please try and calculate the power disposition to the eye.
OPTICAL RADIATION Consider a 10 W laser (mid-day sun is 10 W cm -2 ) The beam is 1 mm in diameter With a power disposition of 1000 W cm -2 This is sufficient to ignite paper or cause skin burns If the beam enters the eye it will be focused by the lens to give a power disposition 100 000 times greater or 10 8 W cm -2 Even if the laser operates at 900 nm (beyond the visible range) it still penetrates the eye and can cause damage.
OPTICAL RADIATION Heat – black body radiation T emperature Colour in K emitted 1,000 Red 1,500 Reddish orange 2,000 Yellowish orange 2,800 Yellow 3,500 Yellowish white 4,500 Warm white 5,500 White • KE of the atom (charge in motion) gives an electromagnetic wave
OPTICAL RADIATION Some of the invisible portions of the electromagnetic spectrum are included in the term ‘optical radiation’. These are the ultraviolet and infrared spectral regions. Although they cannot be seen (the retina doesn’t have detectors for these wavelengths) portions of these spectral regions can penetrate the eye, to a greater or lesser degree. • UVA is transmitted to the retina less efficiently than green lig ht
OPTICAL RADIATION Exposure limits exist for the spectral region 180 nm to 3,000 nm for non- coherent optical radiation and from 180 nm to 1 mm for laser radiation. • Ultraviolet ‘C’ (UVC) 100–280 nm • UVB 280–315 nm • UVA 315–400 nm • Visible 380–780 nm • Infrared ‘A’ (IRA) 780–1,400 nm • IRB 1 400–3,000 nm • IRC 3,000–1,000,000 nm (3 μm to 1 mm)
OPTICAL RADIATION Unit of measure • “irradiance” means the radiant power incident per unit area upon a surface expressed in watts per square metre (W m -2 ) • “radiance” means the radiant flux or power output per unit solid angle per unit area expressed in watts per square metre per steradian ( W m -2 sr -1 ) • “radiant exposure” means the time integral of the irradiance, expressed in joules per square metre (J m -2 )
OPTICAL RADIATION You can access the free download of the Non-binding guide to good practice for implementing Directive 2006/25/EC from the following: http://www.uni- heidelberg.de/md/zentral/universitaet/beschaeftigte/service/s icherheit/leitfaden_eu_optische_strahlung_engl.pdf • Laser classification and safety are in section eight from page 27 • AOR biological effects are in appendix B page 46 onwards • Exposure limits (Annex I and II) from page 123
OPTICAL RADIATION As required by our membership of the EU the British Government produced new legislation on Artificial Optical Radiation (AOR). http://www.legislation.gov.uk/uksi/2010/1140/pdfs/uksi_ 20101140_en.pdf To assist employers in implementing this new legislation the government has produced a useful guide at the web site below: http://www.hse.gov.uk/radiation/nonionising/optical.htm
OPTICAL RADIATION Hazard Whenever electromagnetic radiation interacts with a material, it is likely to deposit some energy at the point of interaction (possible damage mechanism). • We must also consider AOR effects on the skin (requires health surveillance of workers) The most serious long-term effect of UV radiation is the induction of skin cancer. The non-melanoma skin cancers (NMSCs) are basal cell carcinomas and squamous cell. Malignant melanoma is the main cause of skin cancer death, although its incidence is less than NMSC.
OPTICAL RADIATION Where should you be? As an employer with only safe sources • Have a list of all the sources in your workplace (see list in guide page three) • Not on the list? • Let your employees know you only have safe sources – Have a list of workers that have issues with AOR (migraine sufferers) • Review with new equipment
OPTICAL RADIATION As an employer with normally safe sources that could be inappropriately used • Have a list of all these sources in your workplace • Identify what needs to be done to keep your employees safe – Let your employees know what actions they need to take to keep the sources safe when in use • Record and review
OPTICAL RADIATION For one from the following list indicate what instructions you would give to keep your employee safe.
OPTICAL RADIATION Inappropriately used (placed close to eye) safe sources can cause harm. • Ceiling-mounted and task lights without diffusers or filters • Desktop projectors and vehicle headlights • Non-laser medical lights • Multiple photographic flash lamps and art & entertainment lights • UV insect traps • Group 2 lamp systems [see British Standard BS EN 62471: 2008] and class 1M, 2 or 2M lasers
OPTICAL RADIATION As an employer with hazardous sources • Have a list of all these sources in your workplace • Undertake a risk assessment • Identify what control measures are needed to keep your employees safe – see next set of slides • Implement controls and check outcome (Take action if employees are exposed to AOR in excess of the exposure limits) • Record and review
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