MoEFCC defends revised SO₂ emission norms for Thermal Power Plants, cites scientific backing

New Delhi: The Ministry of Environment, Forest and Climate Change (MoEFCC) has issued a strong clarification refuting recent media reports that alleged a dilution of environmental regulations concerning Sulphur Dioxide (SO₂) emissions from thermal power plants (TPPs).

The Ministry asserted that the revised norms, notified on July 11, are grounded in rigorous scientific research and consultations with stakeholders, and do not reflect a weakening of pollution control measures.

The statement came days after the Union environment ministry on July 11 extended deadlines and exempted a large number of coal plants from installing flue gas desulphurisation units.

In its official statement, the Ministry criticized the media coverage of the notification, calling it a “gross misinterpretation” of both the environmental policy and scientific basis underlying the revised emission standards.

The new SO₂ emission norms for TPPs are the result of a comprehensive review process involving extensive consultations with industry stakeholders and premier research institutions.

Among the organizations that contributed to the policy development are the Indian Institute of Technology (IIT) Delhi, the National Institute of Advanced Studies (NIAS), and the National Environmental Engineering Research Institute (NEERI), a constituent of the Council of Scientific and Industrial Research (CSIR).

The Central Pollution Control Board (CPCB) also conducted a detailed scientific review before finalizing the norms. “These norms are not a regulatory rollback,” said the Ministry.

“They represent a rational, evidence-based recalibration that is in alignment with current ambient air quality data, emissions trends from the thermal power sector, and the broader sustainability goals of the country.”

Critics of the revised norms have claimed that they undermine efforts to curb SO₂ pollution and its role in generating harmful fine particulate matter (PM2.5). However, the Ministry contends that such assertions are not supported by current scientific evidence.

According to a detailed analysis conducted by IIT Delhi, sulfate aerosols — which are secondary particles formed from SO₂ — contribute only a minor share to PM concentrations in cities near thermal power plants.

The analysis found that sulfate accounts for just 0.96% to 5.21% of PM2.5 and 0.57% to 3.67% of PM10 in those areas.

“These findings clearly contradict widely circulated claims suggesting that sulfur compounds contribute 12% to 30% of PM2.5 in Indian cities,” the Ministry said. “Such figures are unsubstantiated and significantly overstate the role of SO₂ in India’s particulate pollution burden.

The Ministry also rejected arguments that the National Ambient Air Quality Standards (NAAQS) for SO₂, last updated in 2009, are outdated. It emphasized that revisions to air quality standards must be based on concrete scientific data and health impact assessments not merely on the passage of time.

“Current exposure levels do not indicate that SO₂, under prevailing ambient conditions, poses a major public health concern,” the statement noted.

“Any changes to national standards must be driven by empirical evidence showing significant contribution to PM2.5 levels or health burdens, which current data does not support.” While acknowledging the need for continuous improvement in environmental regulations, the Ministry reaffirmed that its recent move does not signal a departure from its commitment to clean air.

Instead, it emphasized the importance of tailoring regulations based on up-to-date research and on-the-ground realities, rather than blanket assumptions.

“Effective environmental governance must rely on credible scientific analysis, not rhetoric,” the Ministry concluded. “The revised SO₂ norms are the product of such a process one that seeks to balance public health priorities, energy needs, and environmental sustainability.” Ministry said.