Haze and pregnancy in Singapore: what the advisory asks you to change

Singapore’s haze health advisory puts pregnant women in the same row as the elderly and children, and once the air turns unhealthy that row asks for more than the healthy adult row does. At a 24-hour PSI of 101 to 200, on the Pollutant Standards Index, Singapore’s measure of air quality, a healthy adult is told to reduce prolonged or strenuous outdoor exertion. You are told to minimise it. The Ministry of Health (MOH) defines both words on the same page: reduce means do less, minimise means do as little as possible. Above 300 the gap opens again, from minimise outdoor activity to avoid it. Your commute does not need an N95 mask and neither does being indoors, so almost all of the change lands on one thing: time spent exerting yourself outdoors. And the 24-hour PSI, the number the health advisory itself is built on, is not the one that answers “can I go out in the next hour”.

The short version. Two numbers, two jobs: the 24-hour PSI air-quality forecast plans tomorrow, and the 1-hour PM2.5 fine-dust reading decides the next hour. Once the air turns unhealthy, both ask more of you than of a healthy adult. No mask is needed for the commute or indoors. Above a PSI of 200 a mask becomes a question, the same trigger given for chronic lung or heart disease, and MOH asks you to settle it with your own doctor. Feeling unwell is the signal to seek care, and the usual pregnancy warning signs still apply. Correct as of September 2026; the readings change hourly.

What does the haze advisory actually ask you to do differently?

It asks you to do less outdoors, sooner than a healthy adult would have to, and it says so in a table. MOH publishes the Health Advisory for the General Public as three rows against five bands of the Pollutant Standards Index, or PSI, which is Singapore’s 24-hour measure of how bad the air is. A PSI of 101 and above is what MOH calls unhealthy. Pregnant women share the middle row with the elderly and children.

The words are not loose. MOH prints its own glossary under the table: reduce means do less, minimise means do as little as possible, avoid means do not do. Prolonged means continuous exposure for several hours. Strenuous means involving a lot of energy or effort.

Read the middle column against the first and the practical difference shows up twice. In the unhealthy band, 101 to 200, the instruction covers the same activity at a stricter dose: a healthy adult does less of it, you do as little of it as possible. In the very unhealthy band, 201 to 300, the wording changes shape entirely. A healthy adult is still only being asked about prolonged or strenuous exertion. You are being asked about outdoor activity, full stop, whether or not it is strenuous. That is the point at which a slow walk to the shops counts and it did not before.

PSI or PM2.5: which number should you actually check?

Both, for different questions. The National Environment Agency (NEA) publishes two readings, and its own poster says which decision each one is for. The 24-hour PSI forecast is for planning tomorrow. The 1-hour PM2.5 reading is for the next hour.

PM2.5 means fine particles small enough to travel deep into the lungs, measured in micrograms per cubic metre of air. NEA sorts the 1-hour reading into four bands. It carries a separate line for what NEA calls vulnerable persons, defined on the poster as the elderly, pregnant women, children, and people with chronic lung or heart disease.

Something in that second table is worth a second look. On the 24-hour PSI table, pregnancy sits in a middle tier, one notch gentler than chronic lung or heart disease. On the 1-hour PM2.5 table there is no middle tier at all: pregnancy is folded into a single vulnerable persons group alongside chronic lung and heart disease, and gets the same instruction they get. So for the “can I go out in the next hour” decision, the official guidance treats a pregnancy exactly as cautiously as it treats an existing lung condition.

One footnote that matters if you are reading older haze articles: the 3-hour PSI reading was phased out on 7 December 2016. Anything still telling you to check it is out of date. Live readings for both current numbers sit on haze.gov.sg, on nea.gov.sg and in NEA’s myENV app.

Do you need an N95 mask?

Not for the commute, and not indoors. MOH is unusually direct about this: N95 masks are not needed for short exposure “like commuting from home to school or work”, and HealthHub adds the bus-stop-to-shopping-mall hop to the same list. Neither page asks for a mask in an indoor environment. If your day is home, MRT, office, MRT, home, the advisory is not asking you to mask.

The mask question starts at several hours outdoors, and here the two official pages sit at different levels of detail. HealthHub’s guide, contributed by MOH, gives a number: wear one at a PSI above 300 if you are healthy, and above 200 if you are elderly or pregnant. That is the same trigger it gives for chronic lung or heart disease, printed in the same merged cell. MOH’s own haze page gives no number for you at all. It says elderly, pregnant women and people with severe lung or heart problems “should consult their doctor as to whether they should use the N95 mask if they have to be outdoors for several hours”.

Those two are not in conflict. Take a PSI above 200 as the point at which the question becomes live, and take MOH’s sentence as the answer to who decides it. There is a reason MOH routes this through your doctor rather than a threshold: HealthHub notes plainly that wearing an N95 “increases effort in breathing and reduces air intake”, says to take a break from it if you feel uncomfortable, and says to consult a doctor if you are unsure whether you should use one. So this is worth raising at an appointment before the air turns rather than during.

Two practical notes. A surgical mask is not a substitute: HealthHub says normal surgical masks are not effective at filtering fine particles, though they do cut the discomfort from larger ones. And an N95 only works if it fits: HealthHub says the mask has to be fitted properly for each user, sized so that it covers the nose and mouth comfortably without a leak, which is worth checking before you buy a box of one size. If there are older children in the house, the fit problem is harder for them than for you, and we have gone through the kids’ N95 and KN95 masks sold here and what MOH and NEA say about masking children separately.

What happens to your usual walk or prenatal class?

Read your own routine against the two words MOH defines. Prolonged means several hours of continuous exposure. Strenuous means a lot of energy or effort. A twenty-minute walk to the market is neither, and in the unhealthy band the advisory is not aimed at it. A ninety-minute outdoor prenatal yoga session in the sun is prolonged; an outdoor exercise class that leaves you breathing hard is strenuous. Those are what the middle row is about.

Above a PSI of 200 the scope widens and the walk is in as well. MOH’s blunt summary of the whole advisory, in its own FAQ, is that “the best form of protection is for people to stay indoors”. The useful move is usually not to cancel the exercise but to move it inside while the air is bad: a mall, a gym, a corridor, home. HealthHub puts Singapore’s haze in the Southwest Monsoon season, June to September, and both it and MOH define the short-term exposure they discuss as continuous exposure to unhealthy daily average PSI levels over a period of a few days.

Anything about your own exercise programme, how much and what kind, belongs with the person who knows your pregnancy. The advisory sets a ceiling on outdoor exertion. It does not set your baseline.

What can you do at home?

HealthHub’s household list is short, and none of it is pregnancy-specific. That is rather the point: this part is the same for everyone in the flat.

• Close doors and windows when the outdoor air looks like it is getting worse, and open them again when it improves.
• Stay indoors and go easy on physical activity.
• Cut back on anything that adds pollutants indoors, smoking above all.
• Mop or wipe rather than dry-dust or vacuum. Wet cleaning does not throw settled dust back into the air.
• Fans and air-conditioners are fine for circulation and cooling. If your unit draws in unfiltered outdoor air, a window unit typically does, close the outdoor air intake.
• A portable air purifier can bring the indoor particle level down further.

Drink more water than usual. MOH pairs hydration with the advisory every time, and HealthHub is specific that it helps with a dry or itchy throat rather than with anything deeper. If you are weighing a purifier for the bedroom or nursery, we have compared HEPA air purifiers by room size, noise and filter grade, and separately looked at the monitors that tell you whether the purifier is doing anything.

When should you call your clinic?

When you feel unwell. That is the whole haze-specific trigger, and every official page lands on it: MOH says people who are not feeling well should seek medical advice, its FAQ adds that anyone who develops breathing difficulties should consult their doctor, and HealthHub says vulnerable persons who develop symptoms or feel unwell should seek medical attention promptly.

It helps to know what the ordinary version looks like. HealthHub describes short-term haze exposure in healthy people as irritation of the eyes, nose and throat, which usually settles on its own, and notes there can be one to three days of lag between exposure and symptoms. So a scratchy throat two days after a bad Tuesday is the expected pattern rather than a surprise.

Keep watching for the pregnancy warning signs you were already watching for. Bleeding, severe abdominal pain, a sudden change in your baby’s movements, leaking fluid, a severe headache with swelling or blurred vision: those go to your doctor or the hospital on their own merits, hazy day or clear one. HealthHub keeps the full list by trimester in When to Sound the Alarm on Your Pregnancy, and our guide to antenatal care in Singapore, which sits with the rest of our pregnancy guides, covers who to call and when.

On the longer view, be wary of anyone who sounds certain. MOH and HealthHub both say the same careful thing: because international research is built on years of continuous exposure and Singapore’s haze arrives in short episodes, there is “little robust data on the longer-term effects of short-term exposure to haze like the pattern seen in Singapore”. MOH’s advice to pregnant women is one sentence long and it names no outcome: reduce exposure to haze for the health of your unborn baby. Working the table above is doing that.

Does the Haze Subsidy Scheme cover you?

Probably not on the strength of being pregnant, and this is where the grouping that runs through the rest of this article stops. The Haze Subsidy Scheme is the one MOH may switch on during an episode, which then makes haze-related visits cheaper at all polyclinics and at Public Health Preparedness Clinics, or PHPCs. A clinic taking part displays a Haze Subsidy Scheme poster, a PHPC decal, or both, so that is what to look for on the door. It covers allergic rhinitis, asthma, bronchitis, conjunctivitis, chronic obstructive pulmonary disease, upper respiratory tract infections and their complications, with the doctor deciding whether your condition is haze-related.

At PHPCs, its eligibility list names Singapore citizens who are children aged 18 and below, seniors aged 65 and above, or holders of Public Assistance, Pioneer Generation, Merdeka Generation, Community Health Assist Scheme (CHAS) Blue and Orange, or Medical Fee Exemption cards. Pregnancy is not a category on that list. So the same advisory that groups you with children and the elderly for what you may do outdoors does not group you with them at the payment counter, and if you hold a CHAS Blue or Orange card you qualify through the card rather than through the pregnancy.

Two things to check rather than assume. As of 9 September 2026 the scheme page carries a line saying it is not being offered until further notice, and activation is a decision MOH makes episode by episode, so the status on that page is the only status worth trusting. And if your household income might qualify you for a CHAS card, applying takes time: HealthHub says applications are generally processed within 15 working days of a completed application.

What to set up before the next episode

Put NEA’s myENV app on your phone now, while the air is fine, and find both numbers in it once so you are not learning an interface on a bad morning. Know which one you want: the 1-hour PM2.5 for “am I walking to lunch”, the 24-hour PSI forecast for “is Saturday’s class on”. If a mask is likely to be part of your season, try one for fit and raise it at your next appointment rather than at a pharmacy counter during a haze week. And keep the advisory table somewhere you will actually see it, because the whole of it is one instruction repeated at five levels: as the air gets worse, spend less time working hard outside, and start doing that a step earlier than everyone else.

Sources

• Ministry of Health, Haze, page content dated 14 July 2026. The Health Advisory table and the N95 guidance for pregnant women.
• Ministry of Health, FAQ: Impact of Haze on Health. The one-sentence advice to pregnant women, and the long-term-data position.
• HealthHub, contributed by the Ministry of Health, How to Protect Yourself Against the Haze, last reviewed 6 June 2025. The mask table, the household tips and the two readings.
• National Environment Agency, How to Plan Your Outdoor Activities During Haze (PDF), dated July 2024. The 1-hour PM2.5 bands and the vulnerable persons definition.
• HealthHub, Haze Subsidy Scheme, last reviewed 3 July 2025. Eligibility, covered conditions and activation.

Wei Chun

Founder & Editor

A Singapore parent writing the guide he wished he'd had — practical, calm, and grounded in what actually works.

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