Haze season has a pattern. Someone posts the first PSI screenshot, the family chat lights up, and the purifier section of every website runs out of stock. The trick is to prepare while nobody is panicking.
This checklist is general household advice. For health guidance, follow NEA and MOH advisories.
- Before the haze: get your kit ready
- When the numbers climb
- What about the air-con?
- Heading out
- After the haze
- FAQ
Before the haze: get your kit ready
Switch on your purifier and make sure it works. Check the filter and the replacement date. Order a spare filter now rather than when everyone else does. Consider a PM2.5 monitor so you can see what is happening indoors. Bookmark NEA's haze.gov.sg and the myENV app.
No purifier yet? Measure your room, run the CADR calculator, then look at bedroom purifiers or what is hot in Singapore.
When the numbers climb
Close windows and doors. Switch the purifier on early, while the air is still fine, not after the room smells of smoke. Keep it in the room you use most, a little way from walls, with the intake unblocked.
Avoid adding indoor smoke on top of haze: incense, candles and heavy frying all add fine particles.
What about the air-con?
Split air-con units mostly recirculate indoor air, so running one with windows closed keeps outdoor air from coming in. Their built-in filters are not designed for fine haze particles, which is where the purifier comes in.
Heading out
Check the 1-hour PM2.5 reading before you go. NEA's advice for elevated readings is to reduce strenuous outdoor activity for the next hour, and the advice gets stricter at higher bands. Ordinary surgical masks are not designed to filter fine particles, so check NEA and MOH advice on masks.
After the haze
Once NEA's readings are back in the normal range, air out the home. Check your filters, replace them if they are due and restock your spare. Haze season does not always come once.
Quick answers
How early should I switch on the purifier?
As soon as the forecast says the numbers are rising, or when the 1-hour PM2.5 starts climbing. It is easier to keep clean air clean than to clean dirty air.
Should I open windows when the haze clears?
Once NEA's readings are back in the normal band, airing out is reasonable. Check the current numbers first.
Do I need a purifier in every room?
Not necessarily. Prioritise the room you sleep in, then the room you use most.
