CAQM’s sub-committee, responsible for activating Grap, convened to implement measures only after Delhi’s air quality remained in the “severe” range for 48 hours and amid growing public frustration.

Grap-3 also offers the choice for NCR governments to consider suspending in-person classes for children in primary school and taking them online instead.

The measures also came into effect after widespread uproar from citizens who continued to suffer from a relentless onslaught of pollution that engulfed the city in an apocalyptic smoky haze, leaving people with two choices – either remain captive inside their homes or offices with doors and windows shut or step out and bear the toxic air.

In a marked shift from its stance just a day prior, CAQM reversed its initial decision to hold off on Stage-3, citing earlier projections that air quality would improve on Thursday. However, this forecast failed to materialise, and by Thursday, air quality had remained dangerously high.

CAQM’s sub-committee on Grap consists of 12 members. It is headed by NP Shukla, member-technical CAQM as its chairperson and has CAQM member secretary Arvind Nautiyal and CAQM member Sujit Kumar Bajpayee as its members. Other members of this sub-committee include member secretaries of CPCB and the state pollution control boards of Delhi and NCR. Other members are VK Soni from IMD, IITM’s Sachin Ghude, Dr TK Joshi from the Maulana Azad Medical College and director technical of CAQM, Ram Kumar Aggarwal as its members.

The measures rolled out by the CAQM’s sub-committee ban all private C&D works across the city along with all activity by stone crushers and miners across the wider swathe of NCR.

In terms of vehicular restriction, it restricts BS-4 or lower light motor vehicles (LMVs, or simply put cars) from plying in Delhi, Gurugram, Faridabad, Ghaziabad and Gautam Budh Nagar. Further, there are restrictions on the movement of BS-3 and lower medium goods vehicles (MGVs) and Light Commercial Vehicles (LCVs) from plying in the Capital.

Stage-3 also asks interstate buses from NCR to be stopped from entering Delhi if they are not CNG, electric or complying with BS-IV diesel or higher.

Major construction and demolition projects like railway projects, metro, airport, ISBTs, national and defence-related projects, healthcare facilities, linear projects such as roads and flyovers and sanitation projects will continue under this category, according to GRAP guidelines.

Delhi’s AQI touched “severe” for the first time this season on Wednesday, on a day when the Capital and its surrounding region woke up to the season’s first very dense fog with visibility falling to zero.

CAQM, despite the deterioration, opted not to invoke Stage-3 measures, stating an improvement in AQI is expected by Thursday. “The sub-committee has noted this steep rise in AQI of Delhi owing to this episodic event, since this morning. However, owing to stronger winds, the pollutant concentration and thereby the AQI, is expected to start showing a declining trend Thursday onwards and the AQI is likely to move back to the ‘very poor’ category the next day,” the CAQM sub-committee had said on Wednesday evening.

The delay in implementing restrictions has invited criticism from environmental advocates and public health experts, who argue that Grap’s intent is to act pre-emptively rather than in a reactive, emergency mode.

Experts condemned the delay, stressing that residents, particularly the elderly and children, have been breathing harmful air since Wednesday.

“If Stage-3 comes into effect from Friday, it means people have been breathing severe air since Wednesday morning. This particularly is quite harmful for the elderly and children. CAQM, instead of invoking it on Wednesday itself, has taken a delayed response, despite Grap require pre-emptive and emergency level action,” said IIT-Delhi’s Mukesh Khare, an air pollution expert.