Failure modes of control methods for laser generated fume during hair reduction procedures

Laser hair reduction is one of the most commonly performed minimally invasive cosmetic procedures. Risk assessment of a tertiary referral laser dermatology unit in England identified that there are still unknown hazards related to laser-generated fume from procedures that represent approximately half of all treatments in the unit. This uncertainty in fume hazard analysis was raised in response to significantly increasing awareness of respiratory risks and updated guidance on respiratory protective equipment for medical laser procedures because of the COVID-19 pandemic. This paper presented an analysis of the failure modes for the current control methods for laser-generated fume, which involve room ventilation, local exhaust ventilation, and respiratory protective equipment that rely heavily on administrative procedures to function correctly. The new respiratory risk methods guidance also affects the integrity of existing laser safety personal protective equipment. The identified failure methods were then analysed through the collection of laser-generated fume and provided new evidence of the laser-generated plume concentration hazard during in-vivo laser hair reduction procedures. The air quality of the treatment unit was measured over a typical day of procedures using optical particle sizing to calculate the PM_2.5 mass concentration. The results identified a potential failure mechanism with existing control methods, as a maximum concentration of 298 μg/m³ could be observed during the day with all the existing methods in use. This was a single-day and treatment-type study on a laser. However, this analysis provides valuable evidence to laser medical practitioners and medical laser safety officers in any treatment environment of the potential for fume to bypass the current standard existing control methods. The paper presents recommendations for further analysis and the requirement for knowledge of the acute limits of laser-generated fume to understand the hazard potential.