Environmental Characteristics and Mixed Exposure Risks in Small-Scale Beauty Facilities in Vietnam

Abstract

Small-scale beauty facilities constitute a distinctive occupational setting characterized by simultaneous exposure to multiple volatile organic compounds (VOCs) emitted from hairdressing, nail services, and solvent-based cleaning. This study aims to characterize workplace environmental conditions, quantify concentrations of priority VOCs, and assess non-carcinogenic health risks under different exposure scenarios in small-scale beauty facilities in Vietnam. A field-based design was applied across four facilities, integrating structured site surveys, air monitoring, and scenario-based risk assessment under baseline, task-based, and adverse conditions. Toluene and formaldehyde were measured in two sampling campaigns, while acetone was included as an indicator of mixed exposure. Real-time measurements of formaldehyde (HCHO) and total VOCs (TVOC) were conducted to capture short-term variability. Results show that all facilities were micro-scale (15–40 m²) with prolonged exposure duration and widespread open chemical handling practices. Toluene concentrations ranged from 0.014 to 0.024 mg/m³, formaldehyde from 0.005 to 0.027 mg/m³, and acetone up to 0.066 mg/m³. End-of-shift HCHO and TVOC reached 0.45 ppm and 0.47 ppm, respectively. Formaldehyde exhibited greater variability and dominated cumulative risk. One facility recorded a hazard index (HI) exceeding 1, increasing to 1.2872 under adverse conditions. The findings highlight that mixed VOC exposure is strongly influenced by ventilation, service intensity, exposure duration, and chemical handling practices.