CAP. 303]
Radiation (Control of Irradiating Apparatus) Regulations
[1989 Ed.
[Subsidiary]
L4228/90
"half-value layer" means the thickness of material which reduces to half the exposure rate of a particular beam of radiation;
"intensity" means the quantity of radiation passing through a unit area perpendicular to the direction of the beam of radiation per unit of time; “ionometric method” means a method of measurement based on the ionization produced by the radiation which is being measured;
"licence" means a licence issued under section 9 of the Ordinance;
"licensee”, in relation to any irradiating apparatus, means a person holding a licence for the time being in force issued under the Ordinance with respect to that apparatus;
“maximum permissible dose, in relation to persons employed in radiation work, means a dose of radiation-
(a) in the case of skin of the hands, forearms, feet or ankles, of 200 millisieverts in any calendar quarter or 750 millisieverts in any calendar year; or
(b) in the case of any other parts of the body, of 30 millisieverts in any calendar quarter or 50 millisieverts in any calendar year;
"medical practitioner" means a medical practitioner for the time being registered or exempted from registration under the Medical Registration Ordinance (Cap. 161);
"panel" means such committee as the Board may from time to time appoint under section 5 of the Ordinance for the purpose of advising the Board upon matters affecting or concerning the state of health of persons employed or to be employed on, or engaged in, radiation work;
"personnel radiation monitoring device" means a device designed to be worn or carried by an individual for the purpose of measuring exposure to radiation and includes a photographic film suitable for that purpose, placed in an appropriate film holder; (L.N. 229 of 1985)
"photograph" means a photograph of approximate size neither greater than 50 × 70 mm nor smaller than 40 × 70 mm;
"proximity", in relation to any irradiating apparatus, means a position in which a person may be liable to receive a dose of radiation exceeding 15 millisieverts to any part of the body if such position were retained by him for one calendar year;
"quality", in relation to radiation, means the property of the radiation which determines the manner in which it affects and is itself altered by the matter it traverses, expressed quantitatively in terms of equivalent constant potential or half-value layer;
“radiation" and "rays" mean ionizing radiation;
"radiation hazard" means the danger to health arising from exposure to ionizing radiation whether such danger is due to radiation arising from sources outside the human body or to radiation from radioactive substances within the body;