Haze guides

Short explanations of the API, haze, and what to do about it.

• What is the API, and what do the numbers mean?The Air Pollutant Index is published hourly by Malaysia's Department of Environment. Here is what each band means and what to do at each one.2 min read
• Haze in Malaysia: the causes, the season, and when it clearsWhy haze returns most years, which months are worst, and what decides whether an episode persists or breaks.2 min read
• PM2.5 and PM10: the difference, and which one to worry aboutThe two particles behind almost every Malaysian API reading, why size decides the harm, and how a concentration becomes an index number.2 min read
• What API closes schools in Malaysia? The number that decidesThe API reading that usually stops outdoor activities, and the one that usually closes schools. Who actually makes the call, and where the official word appears.2 min read
• API or AQI? Why other apps show a different numberMalaysia publishes the API; most international apps show the US AQI. The same concentration can produce two very different numbers. Here is why.2 min read
• N95 masks for haze: how to choose one and wear itWhy cloth and surgical masks do not help in haze, what makes an N95 different, and why fit matters more than the brand on the box.2 min read
• Air purifiers for haze: what matters, and what does notThe filter you actually need, how to match the machine to the room with CADR, and the features that only add to the price.1 min read