Microbial inactivation and emission of volatile organic compounds in low-heat thermal treatment of infectious healthcare waste.

The growing use of low-temperature waste decontamination devices in hospitals has raised concerns about their inactivation efficiencies and emissions of volatile organic compounds (VOCs). This study evaluated the decontamination efficiencies, as well as VOC and ammonia emissions, of sterilizer devices in four hospitals, including two autoclaves (one with a shredder and one without), a hydroclave, and a dry heating device. Decontamination efficiency was assessed using mechanical and biological indicators, while air pollutants, including VOCs and ammonia, were measured according to National Institute for Occupational Safety and Health (NIOSH) methods. Evaluation of decontamination revealed that the autoclave with a shredder achieved the highest efficiency (up to 100 %), highlighting the importance of shredding, while the autoclave without a shredder demonstrated the lowest performance. Maintaining an appropriate temperature was also identified as a reliable indicator of device efficiency. The hydroclave exhibited the highest VOC and ammonia emissions (128.03 mg/m³ for VOCs and 6.48 mg/m³ for ammonia), while the autoclaves had the lowest ones (45.72 mg/m³ for VOCs and 2.58 mg/m³ for ammonia). The three major VOCs emitted from the sterilizer devices included dichloromethane, ethyl alcohol, and ethyl acetate (with a total level of 22.82 mg/m³). VOC and ammonia emissions were affected by device operational factors and waste composition. These findings highlighted the critical need to optimize hospital waste management practices. Adhering to operational parameters that directly influence device efficiency, along with equipping low-temperature sterilization devices with air pollutant control systems, can significantly minimize emissions, thereby reducing occupational health risks and environmental impacts.