The Graded Response Action Plan (GRAP) is a pre-emptive and emergency framework, or concept, designed to combat severe air pollution in the Delhi-National Capital Region (NCR). Its origin lies in the alarming deterioration of air quality in the region, which led to its formulation under the directions of the Supreme Court of India. The Supreme Court approved the plan in its verdict in the case of M.C. Mehta v. Union of India (2016), and it was officially notified by the Ministry of Environment, Forest and Climate Change (MoEFCC) in 2017.
GRAP works by categorising pollution response measures into four stages based on the severity of the National Air Quality Index (AQI). The stages are: Stage I (Poor, AQI 201–300), Stage II (Very Poor, AQI 301–400), Stage III (Severe, AQI 401–450), and Stage IV (Severe+, AQI > 450). The mechanism is incremental, meaning that measures from all lower stages remain in force as the air quality worsens. For instance, Stage I involves basic measures like enforcing vehicle Pollution Under Control (PUC) norms, while Stage III imposes restrictions on construction activities and specific vehicles.
GRAP connects directly to the National Air Quality Index (AQI), which provides the threshold for activating each stage. Initially enforced by the Environment Pollution (Prevention and Control) Authority (EPCA), its implementation is now the responsibility of the Commission for Air Quality Management (CAQM) in the NCR and Adjoining Areas. The CAQM is a statutory body established under the Commission for Air Quality Management in NCR and Adjoining Areas Act, 2021. GRAP has been revised recently, with the CAQM making modifications in 2023 to make the framework more stringent. These revisions moved certain actions to earlier stages, such as augmenting public transport and ensuring uninterrupted power supply, to trigger a response before pollution peaks.