What you need to know about masks

Masks are coverings that cover the wearer’s nose and mouth. There are different types of masks:

• Face masks which are non-medical masks

• Surgical masks which are also referred to as medical masks

It is important that the mask is worn properly over the nose and mouth and removed properly to protect yourself against COVID-19. Watch this video to find out more. ↗ (opens in new tab)

Face masks

What are face masks?

Face masks such as cloth or fabric masks act as a simple barrier and work as “source control”[1].

“Source control” refers to preventing the wearer’s respiratory droplets from travelling into the air and onto other people when the person wearing the mask coughs, sneezes, talks etc.

These are not suitable for use during medical and surgical procedures in healthcare facilities, where exposure and risk of transmission of infection is higher. These masks may be used by the general public and in community settings. Please refer to MOH’s guidance ↗ (opens in new tab) and FAQs ↗ (opens in new tab) on the use of masks.

Face masks are not regulated as medical devices under the Health Sciences Authority (HSA). Therefore, the quality and effectiveness of face masks are not regulated by HSA.

How to choose a face mask?

For greater effectiveness, choose face masks that have good filtration capability. Examples of such masks include those distributed by the People’s Association and Temasek Foundation.

When selecting a face mask, look for the following specifications:

• Masks with at least 2 to 3 layers of fabric. As a general guide, the material should not be see-through when held against light.

• Layers should preferably be made with different fabrics, including:

  • Water-repellant outer layer

  • Middle filter layer to remove particulates – this can be disposable filter inserts

  • Absorbent inner layer to absorb droplets from wearer’s mouth

• Fabrics with better filtering efficiency

• Fabrics with enough permeability to allow breathing

• Appropriate fit around the face and chin, with complete coverage of the nose and mouth, to prevent leakage of exhaled droplets

Do not choose masks with exhalation valves, as these allow the escape of exhaled droplets from the wearer and exposes others to the risk of infection.

Are face masks useful?

Face masks with good filtering efficiency help prevent people who have COVID-19 from spreading the virus to others by acting as a “source control”. Wearing a mask in public places limits exposure to respiratory droplets and large particles and reduces the risk of community spread of infection[2]. This is especially relevant for asymptomatic or pre-symptomatic infected wearers who feel well and may be unaware that they are infectious[3].

These masks are particularly useful in public settings (e.g. when using public transport) when strict adherence to safe distancing may be challenging.

Surgical masks

What are surgical masks?

Surgical masks are medical masks that offer both “source control” and protection for the wearer against exposure to splashes and sprays of infectious material from others. Therefore, in situations where an individual is in contact with an infected or a potentially infected individual (e.g. visiting a clinic for consultation, patient care givers) a surgical mask is recommended.

Surgical masks offer high filtration efficiency, adequate breathability and reasonable fluid penetration resistance. Their performance characteristics are tested according to a set of standardised test methods based on international standards such as ASTM F2100, EN 14683, Singapore Standard SS 669 series[4] or equivalent to verify that they meet prescribed requirements for bacterial filtration efficiency (at least 95%), breathability, splash resistance etc.

These masks, which are locally or overseas manufactured and used during medical and surgical procedures in healthcare settings, are regulated as medical devices under HSA. Local surgical mask manufacturing facilities are required to be licensed by HSA.

Simple rules for effective masks usage 

Dos

• Ensure that you consistently use and wear an appropriate mask (with good filtration efficiency), according to its purpose as described on the instructions.

• Practise proper removal of used and contaminated masks to prevent the spread of viruses to your hands, face and other contact surfaces. Touch only the straps and not the surface of the mask when removing it. You should wash your hands after disposal of a used mask.

• Reduce the amount of talking when wearing a mask. These actions will lower the amount of condensation produced within the mask and extend its effective life. To ensure effectiveness, change masks if soiled or wet.

• For reusable mask, follow the manufacturer’s instructions on washing, and replace once it is used beyond the recommended number of uses.

Don'ts

• Do not reuse masks as they are contaminated once used.

Please note that this advisory focuses on masks used by consumers in general and does not include N95 and other respirators.

[1] Consideration for wearing cloth face coverings. [link has been removed as it is no longer available] updated 16 July 2020)

[2]    Moghadas SM, Fitzpatrick MC, Sah P, et al. The implications of silent transmission for the control of COVID-19 outbreaks. Proc Natl Acad Sci U S A. 2020;117(30):17513-17515.10.1073/pnas.2008373117.

[3] Scientific Brief: Community Use of Cloth Masks to Control the Spread of SARS-CoV-2 [link has been removed as it is no longer available], updated 20 November 2020).

[4] Singapore Standard SS 669 series:

SS 669 - 1 : 2020 Medical face masks – Part 1 : Filtering half masks to protect against particles – Requirements, testing, marking (Identical adoption of EN 149:2001+A1:2009)

SS 669 - 2 : 2020 Medical face masks – Part 2 : Requirements and test methods (Identical adoption of EN 14683:2019+AC:2019)

SS 669 - 3 : 2020 Medical face masks – Part 3 : Standard specification for performance of materials used in medical face masks (Identical adoption of ASTM F2100-19)

SS 669 - 4 : 2020 Medical face masks – Part 4 : Standard test method for evaluating the bacterial filtration efficiency (BFE) of medical face mask materials, using a biological aerosol of Staphylococcus aureus (Identical adoption of ASTM F2101-19 : 2019)

SS 669 - 5 : 2020 Medical face masks – Part 5 : Standard test method for determining the initial efficiency of materials used in medical face masks to penetration by particulates using latex spheres (Identical adoption of ASTM F2299/F2299M-03(2017))