Do You Really Need An N95 Mask?

Taken from Dr Koh Poh Koon's Facebook page is very useful information about what masks to buy, what works and what doesn't.

Most of the time, no. And there’s one group for whom the answer is definitely no: the group people most want to protect.

N95 masks don’t fit young children.

There’s no properly fitting N95 for a small child’s face, and an N95 works entirely by sealing. A loose mask filters almost nothing while giving the adult holding their hand a strong and false sense of protection.

For young children during haze, the answer is staying indoors with windows shut and the air-conditioning or a purifier running, not a mask.

What an N95 does

N95 filters at least 95% of very fine airborne particles, including the PM2.5 that makes haze harmful. It works by forming a seal against the face so air goes through the filter, not around it.
A surgical mask doesn’t seal and isn’t designed to filter fine particulate. It helps against droplets. For haze it does very little.
Cloth masks do less again for fine particles.

When you need one

Prolonged outdoor exposure when readings are high. Health advisories here are keyed to PSI bands, so check them instead of guessing from how the air looks.
Outdoor work that can’t be avoided during a haze episode.
Not for short trips: walking to the MRT or across a car park doesn’t warrant one.
Not indoors, with windows closed and air-conditioning or a purifier running.
Not for a light haze day if you’re otherwise healthy and staying inside.

Wearing one properly

An N95 worn badly performs like no mask at all, and most people wear them badly.

Both straps. One below the ears at the neck, one above the ears at the crown. Not looped over the ears. That’s a different, non-sealing mask.
Mould the metal nosepiece firmly along the bridge of the nose with both hands, not by pinching with one.
Do a seal check. Cover the mask with both hands and breathe out sharply. Air escaping around the edges, or glasses fogging, means it isn’t sealed.
Facial hair breaks the seal. There’s no way around this.
Don’t touch or adjust it repeatedly while wearing it.
Replace it when it becomes damp, dirty or damaged, or when breathing through it becomes noticeably harder.

Who should be careful

Anyone with heart or lung disease. An N95 increases the effort of breathing. Check with your doctor before relying on one.
In pregnancy, breathing is already harder in later stages. Wearing one is generally fine, but take breaks, avoid exertion in it, and remove it if you feel breathless or lightheaded.
Older children who can manage a proper adult small size and tolerate the seal may be able to use one for genuine outdoor need, but they’ll pull it off, and staying indoors remains better.
Anyone feeling dizzy or breathless in one should take it off and get to clean air.

What to do instead

Check the readings: PSI and PM2.5 on the NEA site or app. Plan the day around them.
Stay indoors with windows shut and air-conditioning running.
Run a HEPA purifier in the room where you spend the most time, particularly bedrooms overnight.
Move exercise indoors. Exertion outdoors means breathing far more of it in.
Keep asthma medication accessible and check expiry dates before the season, not during it.
Watch children with asthma closely: increased coughing or wheezing during a haze episode needs a doctor, not a mask.

Frequently asked questions

Do children need N95 masks during haze?

No, and they can’t use them effectively. There’s no properly fitting N95 for a small child, and the mask works entirely by sealing, so a loose one filters very little while creating false confidence. For young children the answer is staying indoors with windows shut and air-conditioning or a purifier running.

Is a surgical mask any use for haze?

Very little. Surgical masks don’t seal to the face and aren’t designed to filter fine particulate. They help against droplets, which is a different problem.

When should I wear an N95?

For prolonged outdoor exposure when readings are high, or unavoidable outdoor work during a haze episode. Not for short trips, not indoors with the windows shut and air-conditioning running, and not on a light haze day if you’re healthy and staying in.

How do I wear an N95 correctly?

Both straps: one at the neck below the ears, one above the ears at the crown, never looped over the ears. Mould the nosepiece firmly with both hands, then do a seal check by covering the mask and breathing out sharply; escaping air or fogged glasses means it isn’t sealed. Facial hair breaks the seal entirely.

Is it safe to wear an N95 while pregnant?

Generally yes, but it increases the effort of breathing, which is already harder in later pregnancy. Take breaks, avoid exertion while wearing one, and remove it if you feel breathless or lightheaded. Anyone with heart or lung disease should check with a doctor first.

When do I replace an N95?

When it becomes damp, dirty or damaged, or when breathing through it becomes noticeably harder.

What to remember

Most of the time you don’t need one. Check the PSI, stay indoors, shut the windows, run the air-conditioning.

If you do wear one: both straps, mould the nose, seal check. A badly worn N95 performs like nothing.

And don’t put one on a young child. They don’t fit, they don’t seal, and keeping the child indoors is the real protection.