Graded Response Action Plan

The Graded Response Action Plan (GRAP) is an emergency framework for controlling episodes of high air pollution in Delhi and the National Capital Region. It links specified Air Quality Index (AQI) ranges with progressively stricter control measures. Measures can be activated in advance using pollution forecasts rather than waiting for air quality to deteriorate further.

AQI-linked stages

GRAP classifies deteriorating air quality into four stages under the national AQI framework. Each higher stage adds stronger restrictions to measures already operating at lower stages.

• Stage I, Poor: AQI of 201-300 triggers basic enforcement against dust, waste burning and visibly polluting vehicles and industries.
• Stage II, Very Poor: AQI of 301-400 requires intensified dust suppression, mechanical road cleaning and restrictions on polluting equipment and activities.
• Stage III, Severe: AQI of 401-450 brings wider restrictions on construction, demolition, mining, industrial operations and specified vehicle categories, subject to exemptions.
• Stage IV, Severe Plus: AQI above 450 permits the strictest measures, including stronger limits on truck movement, construction and other high-emission activities.

Activation and implementation

The Commission for Air Quality Management (CAQM) invokes, modifies or withdraws stages through its GRAP Sub-Committee after considering observed AQI, forecasts and meteorological conditions. Departments of Delhi, NCR states, pollution control bodies, municipal agencies, traffic police and other authorities implement the prescribed actions.

• The system is anticipatory, because an expected breach of a threshold can justify early action.
• The response is cumulative, so measures under earlier stages generally continue when a higher stage is imposed.
• Restrictions are relaxed when forecasts indicate sustained improvement, preventing unnecessary continuation of emergency controls.

Purpose and limitation

GRAP converts air-quality data into a coordinated administrative response and allows the severity of intervention to match the pollution risk. However, it primarily manages acute pollution episodes; lasting improvement requires year-round control of transport, industry, construction dust, waste burning and other emission sources.