In a move that has sparked sharp debate among environmental experts the Ministry of Environment, Forest and Climate Change has exempted nearly 78% of India coal-based thermal power plants from installing flue gas desulphurisation (FGD) systems devices critical for curbing sulphur dioxide (SO₂) emissions a major source of PM2.5 pollution and acid rain.
Originally mandated in 2015 to install FGD units by 2017, power plants received multiple deadline extensions over the years. The government now says that Category C plants those situated outside critical pollution zones and representing the bulk of India’s thermal capacity are no longer required to comply. Additionally, plants due for retirement before 2030 are allowed exemption upon submitting an undertaking.
The Centre defended the relaxation, citing findings from IIT-Delhi, NEERI, and NIAS that claim SO₂ levels are within acceptable limits and that FGDs may, in fact, raise carbon dioxide and PM levels. However, these government-commissioned studies have come under fire.
Environmental groups, including the Centre for Research on Energy and Clean Air (CREA), argue that official air quality monitors fail to capture the full impact of SO₂ pollution, especially secondary pollutants like PM2.5, which form after emissions drift downwind and undergo chemical reactions. They point to earlier studies showing plumes from thermal plants can travel up to 300 km and persist for up to ten days, potentially worsening air quality in regions far from the source.
While plants near NCR and critically polluted areas must still meet deadlines now pushed to 2027 for some experts warn that the rollback could weaken India’s battle against air pollution. They also question the long-term environmental cost, particularly as SO₂ is known to contribute to respiratory illnesses, heart disease, and acid rain that damages ecosystems and agriculture.
As the country leans heavily on coal for power generation, the decision underscores a growing tension between economic pragmatism and environmental responsibility in India’s energy transition.