The main global air quality problem in recent decades is the so-called fine particle matter, specially particles smaller than 2.5 um. It is common written as PM 2.5. A good air purifier should include the measurement of PM2.5, otherwise better not consider to buy it.
PM2.5 is often to be monitored in house, such as from candle, cooking, fireplace..etc. During winter time In the Netherlands, you will even get higher PM2.5 concentration in your house when your neighbours are warming house through wood burning fireplace. Well, a HEPA air purifier can help you get ride of it and keep the PM2.5 low under safe level. When it is below the safe level, the device will show you “Good” air quality.
But, what is “safe level” actually ?
Logically, an air purifier should react quickly when the PM2.5 is higher than the safe level. Now the question is what “safe level” your air purifier is using inside him ? Have you ever wondered what it means when it is telling you the air quality is “Good” at this moment ?
According to WHO (World Health Organisation), the concentration 25 μg/m3 (24-hours mean) is defined as the safe level of PM2.5 generally while the different countries have their own standard. For instance, China defines 75 μg/m3 as the safe level, which is much higher than WHO. Therefore, when you are using air purifier brand from China, it might still show you “Good” air quality when actually the PM2.5 level inside house would have even reached 65 μg/m3 and you think he is providing you a clean air all the time.
How can I know which PM2.5 standard my air purifier is using?
If you have had an air purifier at home, then better ask the original band manufacturer. We do not have answer here.
If you are the owner of BRISE air purifier, C360 or C200, you never have this doubt because you can always choose which standard you like to use, such as Europe, UK, USA, Taiwan or General WHO standard, while the default is Europe.
With the new model C360, he can even detect PM 0.3 / 1 / 2.5 / 10 at same time and analyses the possible pollutants or allergens.