Health Risk of Hospital Workers toward Exposed to Ethylene Oxide Residues in Central Supply Departments - ความเสี่ยงต่อสุขภาพคนทำงานทีสัมผัสเอทิลีนออกไซด์ ที่ตกค้างในแผนกจ่ายกลางของโรงพยาบาล

Abstract

       Ethylene oxide (EtO) is used widely in hospital as a gaseous sterilant for heat-sensitive medical items and surgical instruments. Health care workers exposure usually results from improper aeration of the EtO chamber after the sterilizing process, or during off-gassing of sterilized items. The purpose of the present study was to assess the residual of EtO gas in the central supply department of the hospital. The present study was carried out by a descriptive study in twenty central supply department of the Provincial and Community hospitals in 5 provinces. The results of this study show 33 EtO chambers in 20 hospitals. The average of their capacity was 136 L (56-530 L). The average lifespan of EtO chambers was 9.8 years (3-25 years). The average of enabled times was 18.7 times per month (2-40 times per month).
Two hundred and forty air samples were collected. Highest concentration of residual EtO gas were found in supply units (0.105 mg/m3), sterilization units and health care worker (0.024 and 0.014 mg/m3, respectively). The residual EtO gas in 2 medical equipments after 1 day of sterilization was found by Miran Foxboro. The concentration of these medical equipments was found. These finding indicated that the EtO gas was residual in supply unit too. Although in most workplaces, time-weighted average (TWA)
concentrations by the stationary sampling were below the threshold limit value (TLV-TWA = 1 ppm by OSHA and 0.1 ppm by NIOSH). Therefore, the health care workers should avoid staying too long in the workplace. The sufficiency of aeration after the sterilization was also important for reducing the residual EtO gas.
Key words: health risk, ethylene oxide, residues, central supply units