ExplainedAir pollution
GRAP explained: the four stages of Delhi's pollution plan and what each one bans
Stage I of the Graded Response Action Plan came into force across Delhi-NCR on Wednesday as the air turned poor. What the plan is, who runs it, what changes at each stage, and why this year's version kicks in harder and sooner.
The short answer
The Graded Response Action Plan (GRAP) is a set of emergency curbs for Delhi and the National Capital Region that tighten in four stages as the air quality index (AQI) worsens: Stage I for poor air (201-300), Stage II for very poor (301-400), Stage III for severe (401-450) and Stage IV for severe plus (above 450). Each stage adds to the ones before it, from dust control and a ban on open burning at Stage I to a halt on non-essential construction and curbs on older cars at Stage III, and a ban on polluting trucks and almost all construction at Stage IV. The Commission for Air Quality Management (CAQM) decides when to invoke or lift each stage, often on the strength of forecasts.
What is GRAP?
It is Delhi-NCR’s emergency rulebook for bad air.
The Graded Response Action Plan is a list of curbs that switch on in stages as the air gets worse. It was first notified in 2017 after the Supreme Court pressed for a ready-made emergency response in the long-running M C Mehta pollution case. It is now run by the Commission for Air Quality Management, the statutory body that covers Delhi and the neighbouring districts of Haryana, Uttar Pradesh and Rajasthan.
The plan is not meant to clean the air on its own. It is a brake, meant to stop a bad spell turning into a dangerous one while longer-term measures do the real work.
How do the stages work?
Each stage is tied to a band of the air quality index, and each adds to the ones below it.
Stage I applies to “poor” air, an AQI of 201 to 300. Stage II covers “very poor”, 301 to 400. Stage III is for “severe”, 401 to 450, and Stage IV for “severe plus”, above 450. When Stage III is in force, everything in Stages I and II still applies.
The commission does not wait for the index to cross a line. A sub-committee watches forecasts from the India Meteorological Department and the Indian Institute of Tropical Meteorology and can invoke a stage when the air is expected to get there. It also lifts stages, sometimes within days, when wind or rain clears the smog.
What each stage of GRAP adds
What does Stage I mean for people now?
Mostly enforcement, not bans on daily life. Under the order issued on Wednesday, agencies must cover construction material, run anti-smog guns and sprinkle water at building and demolition sites. Open burning of leaves, crop waste and rubbish is banned. Traffic police are to step up checks on pollution certificates and act against visibly smoky and overage petrol and diesel vehicles, and inspections of industries, brick kilns and hot-mix plants are to increase.
Buses coming into the region from Haryana, Uttar Pradesh and Rajasthan may enter only if they run on electricity, CNG or BS-VI diesel. Citizens are asked to follow a charter of their own: keep engines tuned, avoid idling at signals, use public transport and not burn waste.
What changes when it gets worse?
At Stage III the city starts to slow down. Non-essential construction and demolition stop, stone crushers and mining shut, and older cars, BS-III petrol and BS-IV diesel four-wheelers, are kept off the roads in Delhi and the nearby districts, with an exemption for persons with disabilities. Primary classes can move to hybrid teaching.
At Stage IV non-essential trucks that pollute are kept out of Delhi, Delhi-registered diesel heavy goods vehicles of BS-IV or older standard are banned except for essential services, and almost all construction stops. In past winters schools moved to hybrid mode for every class except 10 and 12.
Why is the plan different this year?
Because the commission has twice moved curbs earlier. In November 2025, during a run of severe days, it shifted several measures down a stage: power back-up to avoid diesel generators and extra traffic staff moved to Stage I, staggered office hours to Stage II, and working from home for half of office staff from Stage IV to Stage III.
In September this year it approved a further revised schedule with 25 actions at Stage I, eight at Stage II, ten at Stage III and five at Stage IV, merging repeated dust, waste and transport measures into the first stage. Restrictions on older light vehicles now cover Sonipat as well as Gurugram, Faridabad, Ghaziabad and Gautam Buddh Nagar, and curbs on older diesel goods vehicles from outside Delhi sit at Stage III. The commission said more than 1,800 violating units had already received closure orders.
Does it work?
It helps at the margins, but it cannot beat the weather. GRAP targets local sources such as dust, traffic and burning, which can be controlled within days. It does little about smoke from farm fires in Punjab and Haryana or the still, cold air that traps pollution over the plains in November. That is why Delhi’s air often stays bad even with the strictest stage in force, and why critics argue that measures kept for emergencies should be running all year.
The documents
- CAQM approves revised GRAP schedule for National Capital RegionNews On AIR, 29 September 2026