Covid-19: Human Resources Ministry releases Health and Safety Guidance Notes on Ventilation and Indoor Air Quality

The Guidance Notes on Ventilation and Indoor Air Quality to reduce the risks of airborne transmission of the COVID-19 virus at various premises1 (severally a “Guidance Note” and collectively “Guidance Notes”) were recently announced by the Ministry of Human Resources on 13 July 2021.2
 
The Guidance Notes were developed by a technical committee that included indoor air quality specialists and representatives from various organisations such as the Department of Occupational Safety and Health, the Ministry of Health and the Public Works Department.
 
These Guidance Notes, which are based on the Department of Occupational Safety and Health’s code of practice on Indoor Air Quality 20103, are best practices intended to guide the public on improving ventilation and indoor air quality in premises with: (a) a mechanical ventilating and air conditioning (“MVAC”) system; (b) an air conditioning system without fresh air supply; and (c) natural ventilation. The Guidance Notes should be adopted and implemented with inter alia the latest Standard Operating Procedures released by the Majlis Keselamatan Negara

Generally, the COVID-19 virus spreads via close contact between two individuals (with distance less than one metre) when respiratory droplets or aerosols containing the virus are inhaled or come into direct contact with the eyes, nose or mouth of the other person. However, the Guidance Notes also recognise the recent scientific opinions that the COVID-19 virus may spread through airborne transmission, especially in poorly ventilated or crowded indoor settings, as the droplets or aerosols containing the virus may remain suspended in the air or travel further than one metre. As such, the risk of airborne transmission of the COVID-19 virus may be reduced by improving the ventilation and indoor air quality in residential settings, non-residential settings, public areas, and healthcare facilities.    
 
Guidance Note for Residential Settings
 
A building is a residential building when more than 50% of the floor area is used for dwelling purposes, and is categorised into landed properties, and non-landed properties such as low/high rise apartments and condominiums.
 
The Guidance Note for residential settings is set out below:
 
  1. the recommended indoor thermal conditions are between 23°C to 26°C and 40% to 70% relative humidity with clean filtered air;
  2. electric/ceiling fans should be used to increase air circulation;
  3. air-conditioners should be operated as recommended in (a) and (b) above with a small window opening left open barring any excessive infiltration of air;
  4. when air-conditioners are not in use, the windows should be kept open to ventilate room spaces with clean outdoor air;
  5. exhaust fans should be operated in bathrooms and/or common areas in low/high rise apartments;
  6. the water seal in the sanitary system should remain intact and any cracks should be rectified;
  7. for low/high rise apartments, the use of open windows adjacent to or close to neighbouring units should be minimised; whereas the use of balconies in close proximity with neighbouring units should be avoided, to reduce the risk of infection from one apartment unit to another; and
  8. where a household member is ill, suspected or infected with the COVID-19 virus, an isolation space/room should be allocated without the use of air-conditioner but natural ventilation instead. The isolation space/room should have its own bathroom facilities to reduce the risk of infection to other household members.   
Guidance Note for Non-Residential Settings
 
Non-residential buildings include workplaces, schools and universities, accommodation buildings, religious and commercial spaces.
 
The Guidance Note for non-residential settings with different types of air ventilation is summarised below:
 
  1. Centralised Air Conditioning System
  • ensure all components and controls of the centralised MVAC system are maintained and functioning.
  • outdoor fresh air ventilation should be increased to a minimum of 10L/s per person of fresh air. This may be carried out by opening outdoor air dampers to 100% to increase effective dilution ventilation per person;
  • filters should be changed as per the recommended maintenance frequency whilst the filter seals should be checked to avoid bypass;
  • occupancy density in air-conditioned spaces should be reduced. 
  • the indoor temperature should be between 23°C to 26°C and relative humidity should be between 40% to 70%;
  • the building’s water system should be flushed and maintained properly;
  • usage of MERV 13 or higher MERV value filters should be considered in accordance with the capabilities of the MVAC systems; and
  • if the restroom is located adjacent to an occupied space, the exhaust fan should run continuously to keep the negative pressure relative to the corridor or adjacent room.  
  1. Non-Centralised Air Conditioning System
  • windows and doors should be kept open frequently to allow cross natural ventilation and fresh air into the space, save for any poor outdoor air quality or weather. Where windows and doors are open, use of the air conditioning system should be kept at minimum or turned off completely;
  • exhaust fans should be operated in bathrooms or kitchens at maximum capacity;
  • use of portable air cleaners with particle filters of MERV 13 may be considered; and
  • the water seal in the sanitary system should remain intact and any cracks should be rectified.
  1. Naturally Ventilated Spaces
  • windows and doors should be kept open frequently to allow cross natural ventilation and fresh air into the space, save for any poor outdoor air quality or weather;
  • ventilation may be improved by purging the area frequently by opening all doors and windows completely especially when the area is not occupied;
  • do not direct the airflow of the fan directly from one person to another person as it may increase the risk of airborne transmission; and
  • if exhaust fans have been installed, the use of such fans should be considered to increase ventilation i.e. in bathrooms and/or kitchens.
Guidance Note for Public Areas
 
Public areas are defined as spaces where the public normally have unrestricted access and right of way or where anyone is entitled to be physically present.
 
The Guidance Note for public areas is fundamentally the same as those set out above for the Guidance Note for non-residential settings with the additional control methods described below:
 
  1. Engineering Controls
  • increasing the outside air ventilation;
  • increasing the air filtration by inter alia upgrading MVAC filters to MERV 13 (or the highest MERV rating a building’s ventilation system can accommodate) and placing portable air cleaners at high density or occupancy areas; and
  • adjusting or reconfiguring air flows by inter alia operating exhaust fans in restrooms to reduce the risk of indoor airborne transmission.
  1. Administrative Controls
  • implementing work practices designed to reduce crowding or occupancy such as telework, staggered schedules and remote/video meetings; and
  • limiting the use of small spaces that are shared such as laundry rooms and lobbies.
  1. Reconfiguration of Building Spaces and Furnishings
  • the use of partitions to reduce the risks of transmission by minimising direct air flow between individuals in building spaces.
  1. Cleaning and Disinfection
  • where there has been a suspected or confirmed case of COVID-19, cleaning and disinfection should be carried out within 24 hours; 
  • if more than 24 hours have lapsed since the suspected or confirmed case of COVID-19, cleaning would be sufficient unless there is, inter alia, high index transmission of infection in the area and the presence of individuals susceptible to COVID-19; and
  • if more than three days have lapsed since a suspected or confirmed case of COVID-19, no additional cleaning other than the usual cleaning is required.
Guidance Note for Healthcare Facilities
 
Healthcare facilities are premises used for COVID-19 treatment such as centres and wards including but not limited to hospitals, clinics and Pusat Kuarantin dan Rawatan COVID-19.
 
The Guidance Note for healthcare facilities is largely similar to those applicable to the Guidance Note for non-residential settings save for the following:
 
  1. in relation to air-conditioned facilities with mechanical ventilation and air-conditioned facilities without fresh air supply, the use of high-efficiency filters (at least MERV14 or F8) is recommended in AHUs. Filters should be properly installed, regularly inspected, maintained, and cleaned according to manufacturers’ recommendations; and
  1. although stand-alone air cleaners with appropriate filters may be used if no other (short term) strategy can be adopted, it is emphasised that the stand-alone air cleaners do not replace ventilation in any circumstance.
Commentary
 
The publication of the Guidance Notes by the Ministry of Human Resources is certainly welcomed in view of the alarming number of new COVID-19 cases and workplace clusters identified each day. As the Covid-19 virus poses the risk of airborne transmission, it is hoped that the implementation of the countermeasures in the Guidance Notes would alleviate these risks in line with the end goal of the National Recovery Plan.   
 
Alert prepared by Shannon Rajan (Partner) and Jeremiah Ch’ng (Associate) of the Occupational, Safety and Health Practice of Skrine.


This alert contains general information only. It does not constitute legal advice nor an expression of legal opinion and should not be relied upon as such.
 

1 This includes residential settings, non-residential settings, public areas and healthcare facilities.  
3 The Industry Code of Practice on Indoor Air Quality 2010 is available here.