Isoflurane was added to the core list of the EML and EMLc as an inhalational anaesthetic in 2011. The Committee reviewed the evidence on inhalational anaesthetics. Currently halothane (square box) and nitrous oxide are the only inhalational anaesthetics on the EML. Halothane is widely used in both induction and maintenance, in adults and children but has been gradually replaced in developed countries by isoflurane, enflurane, desflurane, and sevoflurane for safety reasons. Ensuring availability of halothane is increasingly problematic in many settings. None of these medicines is best in all situations and the choice is determined by the availability of the medicines and specific vaporizers. The Committee decided to include isoflurane but not enflurane (due to the risks of convulsions) or sevoflurane (due to cost). Halothane should remain, but without a square box, as this would not be listed as the examplar of all inhalation agents. Where available, halothane provides an affordable option for induction and maintenance. However, where availability is an issue, isoflurane provides an acceptable option for maintenance.