Ultrafine particle concentrations during laser hair removal: Effectiveness of smoke evacuators

Laser smoke is a biohazard that contains potentially dangerous toxic and biological components. In laser hair removal (LHR), practitioners undergo prolonged exposure as this procedure is widely used without protective measures. Little is known about the effect of smoke evacuators on ultrafine particle concentrations during LHR. This study aims to assess the effect of different laser devices and different smoke evacuators on the ultrafine particle concentrations in the room during LHR.

In a prospective observational study, we included patients with skin phototypes 2-4 for 755 nm Alexandrite LHR at two study sites, receiving treatment in axillae and pubic areas. Ultrafine particle concentrations were measured during LHR for two different alexandrite lasers, with and without an external smoke evacuator. Moreover, we assessed a device for LHR with a smoke evacuator integrated into the handpiece. Primary outcomes were the concentration of ultrafine particles (0.2-0.3 µm) per m³ at 1 min after initiation of treatment and maximum concentrations.

A total of 15 patients were recruited for routine LHR. Without a smoke evacuator, already at 1 minute after treatment onset, ultrafine particle concentrations rapidly increased. Both external and integrated smoke evacuators were highly effective with a 3.7-7-fold decrease in maximal particle count. Similarly, maximal particle concentrations remained low with both smoke evacuators. At both study sites, particle concentrations decreased slowly (8 min for 50% reduction) when treatment stopped.

LHR procedures generated an increase of ultrafine particles. Both the external and integrated smoke evacuators are highly effective in controlling ultrafine particle concentrations during LHR. Once particle concentrations are elevated and the process had been completed, clearance of ultrafine particles is rather slow.