India AQI Standards

O₃ Safe Level in India

Ground‑level ozone is a harmful air pollutant and a key ingredient in smog; it forms when pollutants react in sunlight.

Safe Levels (AQI Breakpoints)

Averaging time: 8-hour. Units: µg/m³.

Category O₃ Range Averaging Time
Good (AQI 0–50) 0–50 µg/m³ 8-hour
Satisfactory (AQI 51–100) 51–100 µg/m³ 8-hour
Moderate (AQI 101–200) 101–168 µg/m³ 8-hour
Poor (AQI 201–300) 169–208 µg/m³ 8-hour
Very Poor (AQI 301–400) 209–748* µg/m³ 8-hour
Severe (AQI 401–500) 748+* µg/m³ 8-hour

What Happens When O₃ Is High?

  • Satisfactory (51–100): May cause minor breathing discomfort to sensitive people.
  • Moderate (101–200): May cause breathing discomfort to people with lung disease such as asthma and discomfort to people with heart disease, children and older adults.
  • Poor (201–300): May cause breathing discomfort to people on prolonged exposure and discomfort to people with heart disease with short exposure.
  • Very Poor (301–400): May cause respiratory illness on prolonged exposure; effects may be more pronounced in people with lung and heart diseases.
  • Severe (401–500): May cause respiratory effects even on healthy people and serious health impacts on people with lung/heart diseases; impacts may be experienced even during light physical activity.

Why O₃ Matters in India

Ozone is one of the criteria pollutants used in India’s AQI system with short‑term standards for daily reporting.

Check Your Local AQI

See live readings and nearby monitoring stations for your location.

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Precautions to Reduce Exposure

  • Check your local AQI before outdoor exercise and reduce exertion when AQI is Moderate or worse.
  • Limit prolonged outdoor time during peak traffic hours and congestion.
  • Keep windows closed when pollution is high and use an air purifier if available.
  • If you must be outside on poor days, reduce strenuous activity and consider a well‑fitting mask.
  • Prioritize early morning or late evening for outdoor activity when conditions are better.

FAQs About O₃ in India

In India’s AQI system, O₃ between 0–50 µg/m³ (8‑hour) is considered Good.

100 µg/m³ is the upper end of the Satisfactory band; sensitive people may feel discomfort.

Ozone forms when pollutants react in sunlight rather than being emitted directly.

India’s AQI maps 8‑hour ozone concentrations to AQI categories from Good to Severe.

Ozone tends to rise on hot sunny days in urban areas.