Delhi's air quality plunged into the 'severe' category for the first time this year on Tuesday, prompting the Commission for Air Quality Management (CAQM) to enforce emergency measures under Stage 3 of the Graded Response Action Plan (Grap) across the National Capital Region (NCR). The restrictions, which took immediate effect, include a ban on private construction and demolition work and curbs on BS-3 petrol and BS-4 diesel four-wheelers in Delhi, Gurugram, Faridabad, Ghaziabad and Gautam Budh Nagar.
The decision followed a sharp overnight spike in the city's air quality index (AQI) -- from 362 ('very poor') at 4pm on Monday to over 400 ('severe') by 1am Tuesday, and further touching 425 at 9am, according to the Central Pollution Control Board (CPCB). Officials said calm winds and a stable atmosphere trapped pollutants close to the surface, pushing the AQI beyond 400, the threshold when Stage 3 restrictions come into force.
"Actions under Stages 1, 2 and 3 of the extant Grap shall be implemented, monitored and reviewed by all agencies in the entire NCR to ensure that the AQI levels do not rise further. All implementing agencies shall keep strict vigil and intensify measures," CAQM said in a statement on Tuesday morning.
Other restrictions include halting mining and stone-crushing activities across NCR. In addition to curbs on private vehicles, Delhi-registered diesel medium goods vehicles (MGVs) of BS-4 or lower standards will not be allowed to ply in the city unless engaged in essential services. Diesel light commercial vehicles registered outside Delhi are also barred from entering the Capital except when carrying essentials or providing critical services.
CAQM clarified that while BS-4 commercial vehicles were earlier permitted to enter Delhi till October 31, 2026, the relaxation does not apply when Stage 3 measures are in force.
Schools up to Class 5 in Delhi and neighbouring NCR districts have been directed to shift to hybrid mode (online and offline). Following the CAQM order, Delhi's Directorate of Education (DoE) instructed all government, aided, private, municipal and Cantonment Board schools to move younger classes online or partially online "until further orders", advising schools to inform parents and guardians promptly to minimise children's exposure to hazardous air.
To ease peak-hour traffic, CAQM has asked Delhi and NCR state governments to stagger office timings for all public departments and municipal bodies across Delhi, Gurugram, Faridabad, Ghaziabad and Gautam Budh Nagar. Other NCR districts have been urged to take similar steps, while the Centre has been advised to consider staggered timings for its own offices in the region.
While construction and demolition (C&D) activity has been halted, several categories remain exempt. These include essential projects such as railways and Metro works, airport and ISBT operations, defence-related and healthcare projects, sanitation infrastructure, and linear public utilities like highways, flyovers, transmission lines and pipelines. Such projects are suspended only when Stage 4 of Grap is invoked, which happens if AQI crosses 450.
Sunil Dahiya, founder and lead analyst at EnviroCatalysts, said the worsening air crisis reflected the combined impact of local emissions, power plant pollution, industrial discharge, and stubble burning.
"We can't change the meteorological factors, so the only solution left is reducing the emission loads from episodic as well as continuous sources of pollution. That is possible and can be done by the governments in coordination with the Central Pollution Control Board, Delhi Pollution Control Committee and state pollution control boards," he said.