New Delhi, Sep 18 (PTI) The Graded Response Action Plan (GRAP) -- a set of emergency measures to control air pollution in the Delhi-NCR region during winter -- has come into effect earlier than the usual date of October 1, according to officials.

The Commission for Air Quality Management, an autonomous body responsible for preparing the strategy to improve air quality in Delhi and nearby areas, said on Wednesday that polluting buses from NCR states will not be allowed to enter Delhi if the city's air quality index (AQI) reaches Stage III -- 'Severe' (AQI between 401 and 450).

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Exceptions will be made for CNG, BS VI, and electric buses.

The restrictions will not apply to buses or tempo travellers with an all-India tourist permit.

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GRAP is categorised into four stages based on Delhi's air quality: Stage I -- 'Poor' (AQI 201-300); Stage II -- 'Very Poor' (AQI 301-400); Stage III -- 'Severe' (AQI 401-450); and Stage IV -- 'Severe Plus' (AQI >450).

On Wednesday, Delhi's AQI was 115 (Moderate).

(The above story is verified and authored by Press Trust of India (PTI) staff. PTI, India’s premier news agency, employs more than 400 journalists and 500 stringers to cover almost every district and small town in India.. The views appearing in the above post do not reflect the opinions of LatestLY)