Air quality categories

The Air Quality Categories webpage published by the Environment Protection Authority (EPA) Victoria describes the air quality classification system used to communicate current air pollution conditions and associated health advice. It explains the five air quality categories—Good, Fair, Poor, Very Poor, and Extremely Poor—and the pollutant concentration thresholds used to assign these categories based on hourly measurements of ozone, nitrogen dioxide, sulfur dioxide, particulate matter (PM₂.₅ and PM₁₀), and carbon monoxide. The webpage also outlines how overall air quality is determined, provides health guidance for the general population and sensitive groups, and describes the monitoring standards and quality assurance procedures that support Victoria's air quality reporting system.