N95 masks for haze: Reuse, use and replacement guide

N95 masks have sold out at my neighbourhood pharmacy. And I can’t find KN95 or KF94 masks either. Can I use a surgical mask or reusable face mask instead?

“N95 and equivalent masks are the most effective options for protection against haze because they are designed to filter fine particulate matter, including PM2.5, when properly fitted and worn,” said Tan Geak Poh, respiratory and critical care medicine senior consultant at Tan Tock Seng Hospital.

He noted that surgical face masks – which serve primarily to prevent the spread of infectious diseases – provide only limited protection against finer air pollution particles and generally do not provide sufficient protection during significant haze episodes. 

Similarly, cloth or reusable masks have limited effectiveness against PM2.5 unless specifically designed and certified for particulate filtration.

In a 2016 advisory, MOH noted that while surgical masks are not effective in filtering haze particles, they can reduce some discomfort caused by the haze, by preventing larger irritant particles from entering the user’s nose and mouth.

What masks can younger children wear? The N95 masks are too big for them.

There are currently no international certification standards for the use of N95 masks in children, MOH noted in guidelines updated on Oct 15.

The Health Sciences Authority notes that children should not use adult-sized masks or respirators, which may not fit properly and thus may not provide adequate protection. They should instead use those specifically sized for children where possible.

MOH advised that children without heart or lung conditions can use the AIR+ Smart Mask, which comes in smaller sizes suitable for children aged seven and older, and includes a built-in valve for greater breathing comfort.

There are also KF94 and KN95 masks for children, available on e-commerce sites such as Amazon and Shopee as at Oct 16.

When should I use an N95 mask?

Vulnerable people – which include the elderly, pregnant women and those with chronic heart or lung disease – should wear a mask to reduce exposure when the PM2.5 reading exceeds 150, in the high and very high ranges.

“Individuals with underlying heart or lung conditions who experience discomfort, breathlessness, dizziness or other symptoms while wearing N95 masks should seek medical advice,” TTSH’s Tan said.

Under MOH guidelines, for healthy individuals, N95 or equivalent masks are not necessary when the hourly PM2.5 reading is under 250 and they are going outdoors for short periods, such as when commuting from home to school or work.

The ministry also notes that masks are not required in an indoor environment.

In situations where outdoor exposure cannot be avoided – in particular when you are outside for extended periods or when performing strenuous activities that increase breathing or heart rate – N95 masks or their equivalents are recommended, said Tan.

“There is no specific duration that defines ‘extended’ exposure, as health risks depend on the level of air pollution, intensity of physical activity and individual’s health status,” he said.

“In general, the longer the exposure, the greater the potential health impact.”

But the use of such masks is recommended for healthy people when the hourly PM2.5 reading exceeds 250, entering the very high range.

Can N95 masks be reused multiple times?

There is no need to replace N95 or equivalent masks every day when using them for protection against the haze, as they can be reused multiple times, said Tan.

“Instead, users should replace the mask when it becomes damp, dirty, damaged, contaminated or can no longer maintain a good seal against the face,” he said, noting such issues are more likely after prolonged or repeated use.  

Users should check the fit of the mask each time it is worn, examining the nose clip, foam padding and straps. Should these become worn or damaged, the mask should be replaced as they can result in gaps around the face, significantly reducing its protective effects, he said.

Tan added that masks should also be stored properly between uses, and be kept in a clean, dry place and not be shared with others.

Where can I get N95 masks?

N95 masks are available at pharmacies and online marketplaces, though some retailers have placed restrictions on how many each customer can buy amid rising demand.

Free packs of two masks can be collected from community clubs across the islandwide for members of the Pioneer Generation and Merdeka Generation, as well as CHAS Orange and Blue card holders, those holding Medical Fee Exemption cards and ComCare Assistance recipients.

Masks are available via vending machines at selected public transport hubs and social service offices.

Pregnant women, children aged seven to 16 years old and people with medical conditions such as asthma can collect masks at the CCs, but not at the vending machines, which require NRICs to verify eligibility.

To find out more about where they can collect free N95 masks, residents can go to the HazeMaskGoWhere website at www.gowhere.gov.sg/hazemask/.