When the haze rolls in, a familiar scene plays out in many Malaysian households: someone digs out a box of N95 or KN95 masks, hands them around, and everyone heads out the door assuming the job is done.
But a respirator like this isn’t really a “put it on and forget it” tool.
Worn the wrong way, it protects far less than most of us assume.
And for a few groups – pregnant women and children especially – it may not even be the right tool to reach for.
Fit to seal
Haze is made up of very fine particles – small enough to slip straight past a loose surgical mask.
A properly fitted N95 mask is designed to filter at least 95% of test particles around the size that is hardest for the surgical mask filter to capture.
This means that it can substantially reduce exposure to fine haze particles, including PM2.5.
That’s exactly why health authorities point to a well-fitted respirator over an ordinary surgical mask when the air outside turns hazy.
Meanwhile, KN95 respirators are manufactured to China’s GB 2626 standard and are designed to achieve at least 95% particle-filtration efficiency under specified test conditions.
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A genuine, compliant KN95 mask may be a reasonable alternative, but performance also depends heavily on fit.
Many KN95 models use ear loops, which may not seal as reliably as the two headbands commonly used by N95 respirators.
“Well-fitted” is the key word here; a respirator only protects you as well as its seal.
The mask should sit snugly across the nose, cheeks and chin, with no gaps for air to sneak in around the edges.
Here’s the part that catches a lot of people out: facial hair, jewellery or eyewear sitting under the sealing edge can break that seal and let unfiltered air leak straight in.
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If there’s a gap anywhere, the respirator underneath it is doing a lot less than you’d hope.
How long to wear it?
You might wonder how long you can actually wear a face mask.
This is where a lot of misinformation floats around.
Some claim that an N95 or KN95 mask is “only safe for one hour”, or that outdoor trips must be capped at exactly 30 to 40 minutes.
But there is actually no universal time limit.
How long a respirator can be worn comfortably depends on the wearer, activity level, environmental conditions and fit.
If it becomes uncomfortable or difficult to breathe through, move indoors where there should be cleaner air (and not in the middle of a hazy street!) and remove it safely.
ALSO READ: How to keep your indoor air clean
You should replace your respirator when its condition changes, i.e. when it becomes wet, dirty, damaged, misshapen, hard to breathe through or no longer seals properly.
Never wash, heat or attempt to disinfect a disposable N95 or KN95 mask at home.
These methods may damage the respirator, affect its filtration performance or reduce its ability to seal properly.
One more myth worth putting to rest: wearing a well-sealed respirator does increase the effort of breathing, and some people do feel discomfort, tiredness or a mild headache because of that added resistance.
Although respirators can increase breathing effort and discomfort, current evidence does not support the claim that normal use causes dangerous carbon dioxide poisoning in healthy adults.
Vulnerable groups
According to Health Ministry (MOH) haze guidance, N95 respirators are not considered suitable for pregnant women.
As other tight-fitting respirators such as KN95 masks may also increase breathing effort, pregnant women should prioritise avoiding haze exposure and consult their doctor before using one.
For pregnant women, the priority isn’t really “which mask”, it’s “how to avoid needing one” in the first place.
That means staying indoors with cleaner air, and skipping outdoor trips that aren’t necessary while the haze is heavy.
If getting outdoors genuinely can’t be avoided, the safest bet is to check with your doctor about what suits your own circumstances.
MOH guidance also states that N95 respirators are unsuitable for children as these adult-sized respirators may not seal properly on a child’s face.
So, keeping children indoors during heavy haze is equally important.
If you’re managing asthma, chronic obstructive pulmonary disease (COPD), or a heart or lung condition, haze season calls for a bit of a strategy shift too.
Reduce outdoor exposure first.
Keep doors and windows closed when appropriate, and use an air purifier indoors if you have one.
Keep your treatment close by.
Continue medication as prescribed, carry a reliever inhaler if one has been prescribed, and follow your asthma action plan if you have one.
Respond early to warning signs.
If wheezing, dizziness, chest tightness or unusual shortness of breath develops, move immediately to cleaner indoor air and remove the respirator once safe.
Seek urgent medical attention if symptoms are severe, worsen or do not improve.
Kek Jin Er is a pharmacist at Alpro Pharmacy. For more information, email starhealth@thestar.com.my. The information provided is for educational and communication purposes only, and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this article. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
