rate of change of magnetic field strength with time
r.m.s. volts
:
root mean square volts
sr
:
steradian
m
:
meter
cm
:
centimeter
mm
:
millimeter
µm
:
micrometer
nm
:
nanometer
l
:
litre
ml
:
millilitre
s
:
second
µs
:
microsecond
Hz
:
hertz
kHz
:
kilohertz
MHz
:
megahertz
GHz
:
gigahertz
kW
:
kilowatt
W
:
watt
mW
:
milliwatt
µW
:
microwatt
PART I
PRELIMINARY
Citation and commencement
1. These Regulations may be cited as the Radiation Protection (Non-Ionising Radiation) Regulations 1991 and come into operation on 1st February 1992.
Definitions
2. In these Regulations, unless the context otherwise requires —
“accessible location” means any point that can be reached by any part of the human body;
“AEL” means accessible emission limits;
“applicator” means the part of the ultrasound device designed to transmit ultrasonic power from the transducer to the patient or materials, and includes the transducer and any associated housing;
“approved” means approved in writing by the Chief Executive;
“beam” means a collection of rays that may be parallel, convergent or divergent;
“cavity” means that portion of the microwave oven in which food or other materials may be heated, cooked or dried;
“collateral radiation” means any electronic product radiation, except laser radiation, emitted by a laser apparatus as a result of the operation of the laser or any component of the laser apparatus that is physically necessary for the operation of the laser;
“continuous wave” —
(a)
in relation to ultrasound, means a wave in which the ratio of the temporal maximum pressure amplitude to the root-mean-square pressure amplitude, each spatially averaged over the effective radiating surface, is less than or equal to 1.05; and
(b)
in relation to a laser, means an emission of laser radiation for a period of 0.25 second or longer;
“deal” means any activity involving an irradiating apparatus other than use, possess for use and import or export;
“diameter” means the minimum diameter of a circular aperture that, when placed to intercept laser beam with the plane of the circular aperture perpendicular to the direction of propagation of the beam, will permit 86.5% of the total beam power to be transmitted;
“divergence” means the full angle of spread of a laser beam;
“door”, in relation to microwave oven, means a movable barrier which prevents access to the cavity of the microwave oven during operation and whose function is to prevent emission of microwave energy from the passage or opening which provides access to the cavity;
“exit aperture” means an opening or window in the protective enclosure of a laser system that is designed to allow laser radiation to be transmitted outside;
“exposure position”, in relation to ultraviolet sunlamp, means any location, orientation, place or distance relative to the ultraviolet radiating surfaces of the sunlamp at which it is recommended by the manufacturer that the user of the sunlamp be exposed;
“external surface”, in relation to microwave oven means the outside surface of the cabinet or enclosure provided by the manufacturer as part of the microwave oven, including any door, door handle, latch and control knob;
“eye examination” means the following examinations performed by a registered medical practitioner:
(a)
visual acuity examination;
(b)
manifest refraction examination;
(c)
external ocular examination;
(d)
examination by slit lamp;
(e)
examination of the ocular fundus with an ophthalmoscope; and
(f)
any other necessary examination;
“individual” means any natural person;
“installation” means the area of radiation hazard under the administrative control of the person possessing the irradiating apparatus;
“integrated irradiance” means the radiant energy incident per unit area of surface expressed as J/m2;
“irradiance” means radiant power incident per unit area expressed as W/m2;
“irradiating apparatus” means any apparatus of a type specified in the First Schedule;
“laser” means any device that can be made to produce light primarily by the process of stimulated emission;
“laser radiation” means all electromagnetic radiation generated by a laser that is coherent and propagates collinearly through space;
“lasing medium” means a material that emits laser radiation by virtue of stimulated transitions between specific electronic or molecular energy levels;
“leakage radiation” means all radiation other than the useful beam;
“licensee” means a person who holds a licence under the Act;
“maximum exposure time”, in relation to the ultraviolet sunlamp, means the longest time interval for continuous exposure recommended by the manufacturer of a sunlamp;
“maximum timer interval”, in relation to ultraviolet sunlamp, means the longest time interval setting on the timer of a sunlamp;
“medical laser” means any laser product manufactured, designed, intended or promoted for purposes of in vivo diagnostic, surgical or therapeutic laser irradiation of any part of the human body;
“minimum interval between consecutive exposures”, in relation to sunlamp, means the shortest time interval between 2 consecutive exposures recommended by the manufacturer of a sunlamp;
“non-ionising radiation” means electromagnetic radiations and fields with wavelengths greater than 100 nm or acoustic radiations and fields with frequencies below 16 Hz and above 16 kHz;
“person”, includes any company or association or body of persons, corporate or unincorporate;
“primary radiation” means radiation coming directly from any irradiating apparatus;
“protective enclosure” means a structure that encloses a laser and its accessory components and restricts the emission of laser radiation to one or more than one exit aperture;
“protective eyewear” means any device designed to be worn by the user to reduce, directly or indirectly, the radiation reaching the eyes;
“protective housing” means a structure that encloses the components of a laser system and prevents the emission of laser radiation except through an exit aperture;
“pulse” means an intermittent emission of laser radiation for a duration of less than 0.25 second;
“pulse duration” means the time interval measured between the half-peak power points on the leading and trailing edges of a pulse;
“radiation” means non-ionising radiation for the purpose of these Regulations;
“radiation hazard” means the danger to the health of an individual arising from exposure to radiation emitted from an irradiating apparatus;
“radiation level” means the corresponding radiation power density expressed in W/m2;
“radiation work” means work which involves the use, handling or operation of any irradiating apparatus specified in Parts II and III of the First Schedule;
“radiation worker” means any individual who is engaged in or is employed for part or whole of his working time to do radiation work;
“SAR” means specific absorbed rate;
“safety interlock” —
(a)
in relation to a microwave oven, means a device or system of devices which is intended to prevent generation of radiation when access to the cavity is possible;
(b)
in relation to a laser, means a device associated with the protective housing of a laser apparatus to prevent human access to excessive laser radiation;
“scanned laser radiation” means laser radiation having a time varying direction, origin or pattern of propagation with respect to a stationary frame of reference;
“scattered radiation” means radiation which, during its passage through a substance, has been deviated in direction or has been modified by an increase in wave length;
“service” means any adjustment, procedure or servicing method prescribed by the manufacturer of an irradiating apparatus;
“service controls” means any control provided by the manufacturer for the purpose of adjustment of an irradiating apparatus and that, under normal conditions of use, is not accessible to the user of the apparatus;
“shutter” means a mechanism that, in its closed position, intercepts the radiation beam and prevents the emission of radiation from the irradiating apparatus;
“spectral irradiance” means the irradiance resulting from radiation within an infinitesimally small wavelength range expressed as W/m2/nm;
“spectral transmittance” means the spectral irradiance transmitted through protective eyewear divided by the spectral irradiance incident on the protective eyewear;
“timer” means any device that is incorporated into an irradiating apparatus and is capable of terminating the emission of radiation from the apparatus at the end of a preset time interval;
“user controls” means a control provided by the manufacturer for the purpose of operation of an irradiating apparatus that, under normal conditions of use, is accessible to the user of the apparatus.
