Methoxyflurane exposure in ambulances: a controlled laboratory study on paramedic safety

Methoxyflurane, a self-administered fluorinated hydrocarbon, provides rapid, relief for traumatic pain. While low-dose methoxyflurane poses minimal risk, paramedics may experience intermittent exposure. This study assesses occupational risks to enhance paramedic safety, health standards, and patient care directives. Active air sampling was conducted in a Ministry of Health-approved ambulance, in the driver and patient compartment, under controlled conditions, both with and without ventilation. Twelve healthy participants inhaled for 15 min, with samples collected per EPA and ISO standards. Results were adjusted for time weighted average (TWA) exposure. Twenty-four air samples were collected (median age 30.5 years, 50 % female). Exposure concentrations remained below 8-h TWA occupational limits and NIOSH 60-min ceiling limits. With ventilation, 8-h TWA levels were 0.001 ppm (driver) and 0.033 ppm (patient compartment), rising to 0.017 ppm and 0.057 ppm without ventilation. Maximum TWA levels for 22 transports (30-min duration) reached 0.019 ppm (driver) and 0.736 ppm (patient) with ventilation, increasing to 0.377 ppm and 1.254 ppm without. These were based upon worst-case assumptions of 22 treatment and transport events, each lasting 30 min, over a 12 h work shift. Ventilation significantly reduced exposure, with 99.1 % protocol adherence and no adverse events. This controlled study confirms methoxyflurane's safe use in ambulances with exposure well below safety thresholds. Ventilation minimizes potential risk(s), ensuring paramedic safety and uninterrupted pain management.