The return of winter in northern India has once again brought with it the spectre of toxic air. On Wednesday morning, Delhi’s Air Quality Index (AQI) remained in the ‘Poor’ category, recorded at 201 at 5:30 am, with the temperature at 19°C, according to the Early Warning System (EWS) for Delhi. Among city locations, Anand Vihar once again recorded the worst air quality, followed by Wazirpur.
The wider NCR fared worse: Noida’s AQI surged from 228 at 5:00 am to 369 by 7:00 am, Ghaziabad hovered around 320–325, and Faridabad rose from 252 to 267, with a visible smog layer hanging over the region.
The worsening trend follows a spike on Tuesday when Delhi’s 24-hour average AQI hit 211, breaching the ‘Poor’ category for the first time since June. In
response, authorities activated Stage I of the Graded Response Action Plan (GRAP), a set of emergency measures aimed at preventing further deterioration of air quality across the National Capital Region.
But what exactly is GRAP, who implements it, and how does this staged system determine when to act?
What Is GRAP And Why Was It Created?
The Graded Response Action Plan (GRAP) is a predefined, incremental framework of pollution-control measures, designed to be triggered as Delhi-NCR’s air quality deteriorates. The idea is to respond quickly and proportionately, with actions matched to specific levels of pollution to avoid a full-blown public health emergency.
The plan was first proposed by the Central Pollution Control Board (CPCB) and submitted to the Supreme Court in the case M.C. Mehta vs Union of India. In 2016, the court approved the recommendations. GRAP was officially notified by the Ministry of Environment, Forest and Climate Change (MoEFCC) in 2017, making it the national capital’s first legally enforceable pollution emergency framework.
Initially, the plan was enforced by the Environment Pollution (Prevention and Control) Authority (EPCA). However, in 2021, this authority was dissolved and replaced by a new statutory body: the Commission for Air Quality Management in NCR and Adjoining Areas (CAQM), which now has exclusive jurisdiction over air pollution matters in Delhi and surrounding areas of Haryana, Punjab, Uttar Pradesh, and Rajasthan.
What Is CAQM?
The Commission for Air Quality Management (CAQM) is now the sole agency responsible for deciding when and how to implement GRAP. Established under the CAQM Act of 2021, it was created to bring better coordination, forecasting, and action across multiple states.
The CAQM is chaired by a senior government official (rank of Secretary to the Government of India or a State Chief Secretary) and supersedes the powers of central and state pollution control boards in NCR states. It can issue binding directions, impose fines of up to Rs 1 crore, and sentence violators to up to five years’ imprisonment.
The Commission relies heavily on real-time air quality data and forecast models provided by the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM) to make decisions. GRAP measures were initially reactive, triggered after air quality worsened. But since 2022, CAQM has made GRAP a preemptive tool, using AQI forecasts to implement controls in advance.
What Is AQI, And Why Does It Matter To GRAP?
The Air Quality Index (AQI) is the central benchmark used to activate GRAP measures. Introduced by MoEFCC in 2014 under the Swachh Bharat campaign, the AQI simplifies public understanding of complex pollution data.
The AQI ranges from 0 to 500, with higher values indicating worse air. It includes eight key pollutants: PM10, PM2.5, NO2, SO2, CO, ozone (O3), NH3, and lead (Pb), each measured against National Ambient Air Quality Standards (NAAQS).
The AQI bands are:
- 0–50: Good
- 51–100: Satisfactory
- 101–200: Moderate
- 201–300: Poor
- 301–400: Very Poor
- 401–450: Severe
- 451+: Severe+
GRAP stages are directly tied to these AQI bands, and each stage mandates specific emergency actions.
What Are The Stages Of GRAP, And What Happens At Each Level?
GRAP has four stages, activated when the AQI crosses the corresponding thresholds. These actions apply across Delhi and NCR districts in Uttar Pradesh, Haryana, Rajasthan, and Punjab.
Stage I – ‘Poor’ Air Quality (AQI 201–300)
Activated when pollution first becomes health-relevant, this stage imposes restrictions aimed at prevention and early containment.
Key measures include:
- Ban on waste burning and garbage incineration
- Mandatory dust control at construction sites; water sprinkling and wind-breaking measures
- Close inspection of industrial units and emissions
- Enhanced use of CNG in public transport, and promotion of metro/bus usage
- Black carbon audits for heavy vehicles
- Immediate switch to 100 per cent piped natural gas at power plants within 10 km of Delhi
- Citizens are urged to avoid exertion outdoors, report violations, and use public transport
Stage II – ‘Very Poor’ Air Quality (AQI 301–400)
When pollution worsens further, the goal shifts to reducing further emission loads.
Enforcement actions include:
- Ban on diesel generator sets (except for essential services)
- Enhanced road dust control, with mechanical sweeping and frequent sprinkling
- Increased parking fees to discourage private transport
- Ensuring uninterrupted power supply to avoid polluting backup sources
- Targeted action in pollution hotspots
- Tighter control over construction and demolition debris management
This stage encourages citizens to limit use of private vehicles and remain indoors during peak smog hours.
Stage III – ‘Severe’ Air Quality (AQI 401–450)
At this point, the focus shifts to aggressive mitigation.
Mandatory actions:
- Ban on all construction and demolition (except public infrastructure and essential projects)
- Closure of brick kilns, stone crushers, hot mix plants
- Shutdown of mining and stone-crushing units
- Restrictions on certain categories of diesel vehicles in select zones
- Potential online classes for young children
Stage III was previously invoked in January 2025 when the AQI exceeded 350. Once the air quality improved, those restrictions were eased.
Stage IV – ‘Severe+’ Air Quality (AQI > 450)
This is the most extreme level of intervention and is seen as a last resort.
Measures include:
- Complete halt to construction, including highways and roads
- Closure of schools or shift to online learning across NCR
- Odd-even road rationing schemes (based on vehicle registration numbers)
- Ban on diesel-powered private vehicles
- Prohibition on entry of trucks, except for essential goods or clean-fuel vehicles
- Closure of non-essential commercial activities, subject to state government advisories
- Work-from-home mandates for offices wherever possible
What Triggers A Stage Change And Who Decides?
The Sub-Committee on GRAP, under CAQM, holds regular review meetings where it evaluates:
- Real-time AQI data from the Central Pollution Control Board (CPCB)
- Forecast models from IITM and IMD
- Field reports on compliance and weather
These scientific assessments determine whether GRAP stages are escalated or relaxed. Importantly, once a higher stage is activated, measures from all previous stages remain in force.
Why Was GRAP Stage I Enforced On Tuesday?
Delhi’s AQI touched 211 on October 14, the first time since June 11 that it crossed into ‘Poor’ territory. The main pollutants were PM10 and ground-level ozone. The latter is particularly dangerous as it is formed when oxides of nitrogen and volatile organic compounds react in sunlight, common in vehicle emissions and industrial activity.
Officials also noted low wind speeds and clear skies, which allow pollutants to accumulate. According to the Centre’s Air Quality Early Warning System forecast, the six days at least will record ‘poor’ AQI.
How Does GRAP Connect With Stubble Burning And Diwali Pollution?
GRAP was designed with seasonal patterns in mind, particularly post-monsoon agricultural burning, winter wind stagnation, and Diwali fireworks.
A delay in the rice harvest this year, due to late monsoon rains and flooding, may push the stubble burning season into November, rather than October-end. This could mean that Delhi’s air quality around Diwali may be better than in previous years, as per the Indian Express.
Why GRAP Matters
Despite its limitations, GRAP remains a critical emergency toolkit. It allows authorities to act dynamically, escalating or lifting restrictions based on forecasted AQI trends, rather than waiting for a public health crisis.
The CAQM Citizen Charter, updated every season, outlines do’s and don’ts for residents, including limiting personal vehicle use, avoiding outdoor activity during peak hours, and reporting pollution violations to the helpline (1800-180-1708).
