New Delhi: In a significant tightening of industrial emission standards, Commission for Air Quality Management (CAQM) has issued a direction underlining a uniform and more stringent particulate matter (PM) emission limit of 50mg/Nm3 for identified industries operating across Delhi-NCR.The commission, in an earlier direction issued in March 2022, fixed the maximum permissible emission for PM at 80mg/Nm3 while asking the industries to aim for 50mg/Nm3 through suitable technology upgrades and installation of requisite air pollution control devices such as bag filters, cyclonic filters, wet scrubbers, etc.
Nearly four years later, CAQM has issued the revised standards, which will be applicable to large and medium industries from Aug 1, 2026, and to the rest from Oct 1. CAQM has cited previous recommendations made by a technical committee, for which a timeline was set for the industries to install new devices required to achieve the stringent PM emission norm of 50mg/Nm3.According to the order, shared on Friday, “The maximum permissible limit of PM emissions from 17 categories of highly polluting industries identified by CPCB — red category (medium and large) air-polluting industries, food & food processing and textile industries having boilers/thermic fluid heaters, and metal industries having furnaces, operating in Delhi-NCR — shall be 50mg/Nm3.” The standard will not apply to those industrial units that are prescribed a PM emission norm of less than 50mg/Nm3, it added.The move targets industrial stack emissions — a key contributor to elevated PM levels and secondary particulate formation in the region. According to CAQM, the revised standard was based on recommendations of Central Pollution Control Board, backed by a study conducted by Indian Institute of Technology Kanpur and a CPCB technical committee, which found the 50mg/Nm3 benchmark to be both technically achievable and environmentally necessary.Govts of Delhi, Haryana, Uttar Pradesh and Rajasthan, along with their respective pollution control authorities, have been directed to ensure strict implementation of the order and undertake intensive awareness drives.
