The Union Ministry of Environment, Forest and Climate Change (MoEF&CC) has issued a revised notification regarding sulphur dioxide (SO₂) emission standards for coal- and lignite-based thermal power plants. It introduces a new compliance framework based on categories (A, B and C), exemptions, penalties and extensions.
If a thermal power plant intends to retire before December 31, 2030, it does not have to meet the SO₂ emission standards, but only if the plant officially submits an undertaking (a formal written declaration) to both the Central Pollution Control Board (CPCB) and the Central Electricity Authority, stating that the plant will be retired by December 31, 2030.
Such plants shall be levied environmental compensation from December 31, 2030, at the rate of Rs 0.4 per unit of electricity generated, if their operation continues beyond the date specified in the undertaking without meeting the prescribed standards.
Plants are divided into three categories based on location. Category A are plants within 10 kilometres of the National Capital Region or cities with a population exceeding 1 million. Category B plants fall within 10 km of Critically Polluted Areas (CPA) or non-attainment cities. All other plants would fall in Category C.
All existing and under-construction Category A plants must comply with SO₂ emission standards by the end of 2027. New Category A plants (commissioned after 2027) will not be permitted to begin operations unless they already meet the prescribed SO₂ norms.
The applicability of SO₂ standards to Category B plants will be determined by the central government. For existing plants, if a plant already holds environmental clearance (EC), it may apply for a review to determine whether the SO₂ standards should apply. This application must be submitted via the PARIVESH portal within six months from the date of notification.
Two outcomes are possible. If the SO₂ standards are deemed applicable, they will take effect from December 31, 2028. If the SO₂ standards are not deemed applicable, the plant must still comply with the stack height requirements as per Notification GSR 742(E), dated August 30, 1990, by December 31, 2028.
For upcoming plants, where EC is not yet granted. The applicability of SO₂ norms will be determined during the EC process under the EIA Notification, 2006. If applicable, the EC will specify the compliance timeline. If not, the plant must still adhere to the stack height requirements outlined in the 1990 notification.
For plants that do not apply for review. If an existing plant fails to apply for review within six months, the SO₂ emission standards shall automatically apply from December 31, 2028.
Category C thermal power plants are exempt from the SO₂ emission standards. However, they must comply with the stack height requirements as specified in Notification GSR 742(E), dated August 30, 1990. All existing Category C TPPs must ensure compliance with this requirement by December 31, 2029.
The central government has the authority to grant extensions for compliance with SO₂ emission norms, but only based on recommendations from the CPCB. If advised, the government may issue an official order to allow additional time.
Thermal power plants that continue operations without compliance (and are not retiring) will face penalties in the form of environmental compensation.
Here are some perspectives by Delhi-based think tank Centre for Science and Environment (CSE) on the order.
Blanket exemption for Category C: Exempting all Category C plants from SO₂ norms solely based on location overlooks cumulative pollution, especially in areas like Singrauli or Korba, which are not “officially” CPAs but are still heavily impacted. Notably, over 75 per cent of India’s thermal power capacity — approximately 166,885.5 megawatts — falls under Category C. Such broad exemptions undermine the purpose of emission standards and pose a significant threat to public health and environmental sustainability.
Case-by-case for Category B is a loophole: Allowing SO₂ compliance for Category B plants to be determined on a “case-by-case” basis introduces a major regulatory loophole. This ambiguous and subjective approach leads to inconsistency, delays and lack of accountability. For a pollutant like SO₂, whose health impacts are well-documented, such discretion dilutes the integrity of environmental regulation and undermines the core objective of emission standards.
Government’s extension powers: Enabling the government to grant extensions based on CPCB advice may result in further delays in pollution control. Past experience suggests compliance timelines are often pushed back.
The revised notification weakens India’s clean air ambitions by diluting or removing SO₂ norms for Category B and C thermal power plants, which together represent the majority of the country’s coal capacity. These exemptions threaten to derail progress on industrial air pollution control, endanger public health and undermine the efficacy of India’s environmental regulations.