PM2.5 are very small particles usually found in smoke. They have a diameter of 2.5 micrometres (0.0025 mm) or smaller.
PM2.5 particles are a common air pollutant. We measure PM2.5 at sites around Victoria.
Health effects of PM2.5 particles
Breathing in PM2.5 particles can affect your health. PM2.5 particles are small enough for you to breath them deeply into your lungs. Sometimes particles can enter your bloodstream.
People who are sensitive to air pollution might experience symptoms when PM2.5 levels are high. This includes people with heart or lung conditions. Symptoms can include:
- chest tightness
- difficulty breathing.
Call 000 if you experience chest pain or difficulty breathing.
Find out more about what to do when it’s smoky outside.
Sources of PM2.5 particles
Common sources of PM2.5 particles include:
PM2.5 on EPA AirWatch
- the last hour (1-hour average)
- the last 24 hours (rolling 24-hour average).
|Air quality category||PM2.5 µg/m3 averaged over 1 hour||PM2.5 µg/m3 averaged over 24 hours|
|Good||Less than 25||Less than 12.5|
|Extremely poor||More than 300||More than 150|
Air quality standards for PM2.5
We compare PM2.5 data to national air quality standards. These are incorporated into the State Environment Protection Policy (Ambient Air Quality).
There is currently no national standard for the one-hour PM2.5 average. For one-hour PM2.5 data, we use the value 62 µg/m3 to trigger a ‘poor’ air quality category.
|National standard||Averaging time|
|25 µg/m3||24 hours|
Read more about air quality
Reviewed 13 January 2021