Authors (including presenting author) :
Ho VKC(1), Ho JNY(1), Yeung RYS(1), Cheng CPY(1), Chan KY(1), Tsang ZST (1),
Lam WWM (2), Yip WWT (3), Leung MKW (4), Lam PH (4)
Affiliation :
(1) Occupational Safety & Health Office, NTEC
(2) Cluster Hospital Planning & Facility Management Division, NTEC
(3) Electrical Mechanical Service Department Health Sector Services (NTE) Subdivision
(4) Family Medicine Department, NTEC
Introduction :
Ventilation plays a critical role in maintaining a healthy indoor environment in healthcare facilities such as hospitals and out-patient clinics. According to the “Simple Guide to Health Risk Assessment” published by Labour Department in 2004, the adequacy of ventilation can be checked by measuring the indoor carbon dioxide level. If its level is constantly greater than 1000 ppm, this may indicate a concern with the ventilation system to remove normal contaminants from human occupants and to satisfy comfort criteria. To ensure staff wellbeing, it is a HA OSH policy to assess the CO2 concentration level in General Out-Patient Clinic (GOPC) annually to ensure good ventilation is maintained in these institutions where central mechanical monitoring system is generally unavailable due to their isolated locations and aging buildings. This checking mechanism was further enhanced in NTEC by implementing a 3 –tier CO2 monitoring system to ensure continuous and better monitoring.
Objectives :
To develop a three-tier mechanism for CO2 concentration monitoring, with an aim to:
- Close and continuous monitoring of CO2 centration level in GOPCs in NTEC
- Early notification of ventilation system deficiency and reporting to appropriate parties for early rectification
- Empowerment of clinic i/c to proactively monitor the performance of ventilation system in the clinic
Methodology :
1st Tier Monitoring
Daily checking by clinic i/c using a smart CO2 detector which are placed in Pharmacy, Treatment room & Shroff. The clinic i/c and pharmacy i/c record the CO2 level reading shown on the detector every working day between 3pm to 4:30pm. Alert will be raised when the reading is above 1000ppm. If similar reading (i.e >1000ppm) persists for 3 days or a reading of 1500ppm in any single episode, the i/c should report to EMSD immediately for ventilation system inspection and repair if necessary.
2nd Tier Monitoring
Quarterly checking by EMSD using a handheld CO2 monitor and air current testers. EMSD will check the CO2 concentration level in Pharmacy, Treatment Room & Shroff every 3 months. The measurement time is between 3pm to 4:30pm on a regular working day. Action level is >1000ppm. In addition to monitoring CO2 concentration, the airflow in all consultation rooms, pharmacy, Shroff, fever cohort room will be checked to ensure the air flow from clean to less clean areas.
3rd Tier Monitoring
Annual assessment by Cluster OSH team using a handheld CO2 monitor and air current testers. Cluster OSH team will check the CO2 concentration level and airflow direction in all consultation rooms, pharmacy, Shroff, treatment room, fever cohort room. The measurement time is between 3pm to 4:30pm on a regular working day. Action level is >1000ppm and/or any deviation from the principle of air flow from clean to less clean areas
Result & Outcome :
A trial was piloted in three GOPCs namely Yuen Chau Kok GOPC, Tai Po Jockey Club Clinic & Fanling Family Medicine Clinic from June 2024 to July 2024. One episode of 3 continuous readings exceeding 1000ppm was reported. EMSD conducted further adjustments on the system to address the ventilation demand and rectify the situations. A large-scale implementation was taken place in other 4 GOPCs in September 2024. As of 31/12/2024, three cases of “above the norm reading” were reported. Ventilation issues were identified very early in all cases and were promptly rectified.
This demonstrated the successful implementation of the three-tier mechanism enabling the continuous monitoring of CO2 level and the proactive maintenance of the ventilation system by EMSD. A healthy indoor working environment is maintained in the NTEC GOPCs and the staff wellbeing is safeguarded.
