The results of radiation leakage surveys performed annually on commercial microwave ovens in hospitals

The purpose of this paper is (1) to report the leakage levels from a large number of microwave ovens in regular hospital use tested annually over an 8-year period, (2) investigate cases with leakage in excess of 50 W m-2, (3) perform a hazard analysis in order to assess exposure of staff and (4) recommend a policy for routine safety checks. Since 1980, all microwave ovens used by personnel employed by seven Area Health Boards in the West of Scotland have been surveyed annually by Radiation Physics staff within the Department of Clinical Physics and Bio-Engineering. During the survey, tests were carried out to check if (1) microwaves are generated before the door is closed, (2) the unit switches off when the door is opened, (3) there are warning lights or other visible indications of mains power and microwave production, (4) the unit restarts when the door is closed, (5) leakage levels exceed 50 W m-2 at 5 cm, (6) the mechanical or electrical condition requires attention and (7) the state of cleanliness is unsatisfactory.