LAUSR

sion Advisory Committee on Toxic Substances identified an occupational exposure standard for Isoflurane of 50 ppm over an 8-h timeweighted average at which there is no significant risk to health [3]. This remains the current of current workplace exposure limit in the latest Control of Substances Hazardous to Health (COSHH) guidance (there are no limits currently available for newer agents) [4]. The detected values in Tallent’s study never reached 50 ppm, even in the control group. However, the principle of ‘as low as reasonably practicable’ should still be adhered to and steps taken to reduce the workplace concentrations of these anaesthetic agents. An alternative solution would be to ensure adequate ventilation within the recovery room to achieve at least the recommended minimum of 15 air changes per hour [5]. Over the long-term, this is likely to be more cost-efficient and produces less medical waste than the ISO-Gard mask.