Singapore residents began collecting two reusable masks each yesterday, in the fourth nationwide reusable mask distribution exercise, to help shield against Covid-19.

A Temasek Foundation initiative, the masks can be collected from StayMasked vending machines at about 800 locations by scanning the barcodes of an NRIC, a school smartcard, birth certificate, FIN or any government-issued identification with a barcode. They can be collected over a two-week period until Oct 4. Although a useful and sustainable alternative to single-use disposable masks, reusable masks should be washed regularly and replaced after a recommended period of time.

Here are some things to note about reusable masks.

Q How long should I use the new reusable masks?

A The latest masks given out by Temasek Foundation are for daily use. Each mask can be washed up to 30 times.

Infectious diseases expert Leong Hoe Nam advises users to check that the mask fits their face and cheeks well, as unfiltered air could enter through the side of a loose mask.

When used on a "wear one, wash one" cycle daily, each mask kit with a pair should last for two months. After that, the masks remain usable, but their anti-microbial effectiveness and filtration are less effective.

Q What is the best method to wash the reusable mask?

A Washing and drying is simple but needs to be done correctly so the mask remains effective for a longer period of time.

Use a gentle soap and lukewarm water solution. Do not use antiseptic detergent or bleach.

The mask manufacturer says the masks may be soaked in water for a longer period of time to wash off stains from cosmetics. It is not advisable to use make-up remover as it may affect the protective qualities of these masks.

Q How often should I wash my reusable mask?

A The mask should be washed after each day of use, according to the guidelines given in the mask kit. Dr Leong advises users to be careful when washing the mask as aggressive washing or the use of a washboard to clean the fabric may damage it quickly.

Q How do I dispose of the reusable mask after the recommended period of use?

A The face mask should be disposed of as you would a surgical mask - in a rubbish bag with other waste or in a bin. Alternatively, cleaned masks can be upcycled in various ways.

For example, they can be repurposed as a cleaning cloth, or a pouch for your spectacles or keys, since they are made of cotton.

Q Why should I stop wearing the reusable mask after the recommended period of use?

A After 30 washes, the antimicrobial as well as filtration properties of the mask become less effective. Dr Leong indicated the mask's effectiveness could drop by between 10 and 15 per cent.