DRY HEAT STERILISATION

Dr Ong Seh Hong asked the Minister for Health (a) whether his Ministry will allow Dry Air Steriliser to be used as a form of sterilization at general practitioners' clinic; and, if not (b) what is the rationale for not allowing this use.

Mr Lim Hng Kiang: Steam autoclaving is recommended by the Ministry's Advisory Committee on Infection Control as a method for sterilisation of all heat-stable surgical instruments. Dry heat using a hot-air oven is only recommended for materials that might be damaged by moist heat. Examples of such materials include powder and fine instruments used for microsurgery.

Dry heat sterilisation process is more difficult to control and monitor because of the following:

(i) the long duration of time taken to reach recommended temperatures to achieve optimum sterilisation (time taken may vary from 1/2 hour to 1 hour depending on the make of the hot air oven);

(ii) uneven distribution of heat, and therefore proper sterility cannot be assured unless other monitoring devices, such as biological indicators, are used to show that sterility has been achieved.

The Ministry's primary concern is patient safety and infection control. Health care institutions should use the recommended method to sterilise reusable heat stable instruments. Alternatively, they could use sterile disposable instruments.