1. The Code of Practice for ECCs indicates that good indoor air quality practices are mandatory for youth facilities only. Why is that so?
Indoor air quality affects the comfort and well-being of those who occupy indoor spaces. The occupants of youth facilities, including young children, belong to the vulnerable group and hence, it is important for premises managers and Environmental Control Coordinators (ECCs) to put in place measures to ensure good indoor air quality in these specified premises.
The Premises Managers and ECCs can take reference from the Code of Practice for Indoor Quality for Air-Conditioned Premises (SS 554: 2016+A1:2021), which specifies good practices in managing indoor air quality as well as standards and limits of indoor air quality parameters.
2. The Code of Practice for ECCs indicates that periodic indoor air quality audits should be conducted at least once every three years. Who will conduct these periodic indoor air quality audits?
Premises Managers will be required to get accredited labs to conduct the periodic IAQ audits (at least once every 3 years) and the audit should include measurements of the recommended IAQ parameters stipulated in the Code of Practice for Indoor Air Quality for Air-conditioned Premises (SS 554: 2016+A1:2021). IAQ audits after major renovations should include measurements of parameters for Formaldehyde and Total Volatile Organic Compounds (TVOCs). In cases where the parameters exceed the acceptable limits stated in SS554:2016+A1:2021, ECCs and PMs should follow up to identify the cause(s) and rectify the situation accordingly.
3. Are the mandatory indoor air quality (IAQ) practices included in the Code of Practice because of COVID-19?
NEA, together with the relevant authorities, had begun work on the environmental sanitation regime as early as 2018, following a series of gastroenteritis outbreaks which affected preschools. In 2019, NEA convened an Environmental Sanitation Technical Committee to develop national baseline standards on environmental sanitation for designated high-risk non-healthcare premises. Since 2020, we have been working with the sector lead agencies to include good indoor air quality practices as part of the sector specific requirements for youth facilities while the other premises will be encouraged to adopt as best practices.
4. Is there a reference document for indoor air quality (IAQ) audits?
Premises managers and ECCs should reference the Singapore Standard Code of practice for indoor air quality for air-conditioned buildings (SS554:2016+A1:2021), which specifies IAQ that will be acceptable to the majority of building occupants and that will minimise risk of adverse health effects. It provides information, advice and guidance on measures to improve IAQ in air-conditioned environments, as well as recommended limits for IAQ parameters.
SS554:2016+A1:2021 and some 40 other standards (accurate as of 18 February 2022) are currently available for free viewing at https://www.singaporestandardseshop.sg/Covid19/Desktop. You may also purchase SS554:2016+A1:2021 for download at the Singapore Standards E-shop.
5. Who may be engaged to conduct IAQ audits?
Laboratories accredited by the Singapore Accreditation Council (SAC) for IAQ testing may be engaged to conduct IAQ audits.
For a list of these laboratories, refer to the SAC website at https://sac-accreditations.gov.sg. From the “Accredited Org” tab on the main page, select “Search accredited organisations”. In the dropdown menu under Scheme, select ‘Laboratories (SAC-SINGLAS)’, then select ‘Environmental Testing’ and ‘Indoor Air Quality’ in the next 2 fields respectively.
6. Is there a recommended number of IAQ sampling points per premises?
The SS554:2016+A1:2021 provides guidance on the number and locations of sampling points in IAQ audits.
At least one sample should be taken from each separated area served by a separate air handling unit (AHU). For premises/spaces served by fan coil units or any air-conditioning or air distribution system, the number of sampling points is determined by floor area:
Area of floor(m2)
Minimum number of sampling points
1 point for every 500 m2
3,000 to 5,000
6, with 1 additional point for every 1,000 m2
5,000 to 10,000
8, with 1 additional point for every 1,250 m2
Outdoor measurements should be performed whenever indoor measurements are taken. The outdoor sampling point should be located at or near locations that would represent the conditions of outdoor air that is introduced or infiltrates the indoor environment being audited.
7. What should an IAQ audit cover?
a) General or periodic IAQ audits should typically involve measurements of all 10 Recommended IAQ Parameters listed in Table 1 of the SS554:2016+A1:2021, which are general indicators of IAQ (below). These parameters should be assessed during periods of occupancy.
1. Air temperature
6. Carbon dioxide
2. Relative humidity
7. Carbon monoxide
3. Air movement
9. Total volatile organic compounds (calibrated to isobutylene)
5. Respirable Suspended Particles
10. Total viable bacteria count
Besides these general IAQ indicators, you may also wish to monitor other airborne contaminants arising from specific sources (e.g. nitrogen dioxide from cooking/burning activities, ozone from significant photocopying/printing activity). Examples of these are listed in Table 2 of SS554:2016+A1:2021 and reproduced below:
1. Nitrogen dioxide
6. Semi volatile and volatile organic compounds
(b) IAQ audits following renovation works and before occupancy should include measurements of the following contaminants of concern:
2. Total volatile organic compounds (TVOCs)
4. Respirable Suspended Particles
5. Asbestos (for buildings where asbestos is present)
This is due to the possible introduction of these contaminants during the renovation works and emissions from the building materials used (e.g. chemical off-gassing from materials used).
It is prudent to clarify with the IAQ auditor which parameters will be assessed in the IAQ audit. It is usually possible to tailor the IAQ audit to your requirements.