Investigations of some aspects of atmospheric pollution by anaesthetic gases. I: Diffusion of halothane across plastic and rubber tubes.
Plastic and rubber tubing, of the types used frequently to convey anaesthetic gases to and from the patient, or anaesthetic waste gases out of the operating theatre, were assessed for their capacity to allow diffusion of halothane through the tube wall. The magnitude of this effect has been calculated in relation to pollution of the operating theatre atmosphere under different circumstances.
Gas exhaust valve
Anaesthesia's timely editorial (27, 1 (1972) ) on the deleterious effects of pollution by anaesthetic gases within the operating theatre stresses the need for some simple device whereby all expired vapours can be ducted to the exterior. The apparatus described here has been designed for this purpose and has been in constant use for the last nine months. Figure 1 shows that it is essentially a simple, spring-loaded non-adjustable fhp valve to which has been added an adjustable tapered vent which controls the volume of exhaust gases passing the valve. The unit is switched into or out of use by a simple lever movement thus enabling the anaesthetist to close the circuit easily and quickly without having to alter the tapered vent. The valve is a spring-loaded Teflon flap valve and the re-
MEASUREMENTS OF HALOTHANE IN THE ATMOSPHERE OF AN OPERATING THEATRE AND IN EXPIRED AIRAND BLOOD OF THE PERSONNEL DURING ROUTINE ANAESTHETIC WORK
The exposure of operating‐theatre personnel to vapours of halothane during routine anaesthetic work was studied. The concentrations of halothane in the atmosphere of an operating theatre and in expired air and blood from the personnel were determined by means of gas chromatography. Possible deleterious effects of repeated exposures are discussed. The need for reducing the amount of waste anaesthetic vapours in operating theatres is pointed out.