Delhi's air has a familiar problem every festive season. The lights go up, celebrations begin, and the question everyone asks is: will the air become difficult to breathe once the fireworks start?

In 2025, Delhi recorded an Air Quality Index (AQI) of 345 on Diwali, placing it in the very poor category. The concerning part? Certified green crackers were permitted under court directions. So, are these supposedly cleaner alternatives making a difference, or is the promise bigger than the result?

The answer is not black and white. Green firecrackers can reduce certain emissions, but they cannot guarantee clean air. To understand why, we need to look at the science, Delhi's air-quality data and the rules governing their use.

What Are Green Firecrackers, and How Do They Differ From Conventional Crackers?

Conventional fireworks use fuels, oxidisers and metal salts to produce explosions, colours and sparks. Their combustion releases particulate matter, gases and other pollutants into the atmosphere.

Green crackers use modified chemical formulations designed to reduce specific emissions while retaining their basic visual and sound effects. India's Council of Scientific and Industrial Research–National Environmental Engineering Research Institute (CSIR-NEERI) has developed and evaluated these formulations.

According to CSIR-NEERI's official green firecracker programme, qualifying products are designed to achieve at least 30% lower particulate matter emissions, or meet the specified alternative criteria for particulate and gaseous emission reductions.

However, these figures apply to qualifying formulations compared with corresponding conventional products. They do not mean every cracker produces identical results or that all harmful emissions disappear.

How Much Pollution Can Green Crackers Actually Reduce?

The research offers some encouraging findings.

In submissions before the Supreme Court, the Centre cited laboratory tests showing a 45–60% reduction in PM10 emissions from certain next-generation products. CSIR-NEERI has also reported that its STAR-F flower-pot formulation reduced PM10 emissions by 45.5% and PM2.5 emissions by 35.6% compared with the corresponding conventional formulation.

PM10 refers to inhalable particles measuring up to 10 micrometres, while PM2.5 includes finer particles that can penetrate deep into the lungs. Both are important when assessing the effects of fireworks on air quality.

But there is a catch. Lower emissions in a laboratory do not automatically translate into a similar reduction in a city's overall pollution levels. The outcome depends on the products used, the number burst, weather conditions and existing emissions.

Delhi's Diwali AQI: What Do the Numbers Tell Us?

Delhi's air-quality history offers useful context. According to CPCB figures reported by the Hindustan Times, the city's 24-hour average AQI on Diwali was 218 in 2023, 328 in 2024 and 345 in 2025. In 2020, it reached 414, classified as severe.

The 2023 reading coincided with favourable weather that helped pollutants disperse. Yet particulate levels still rose after fireworks were burst.

In 2025, the situation was particularly concerning. An HT analysis of Diwali PM2.5 levels found that average PM2.5 concentrations across eight monitoring stations with consistent historical data peaked at 785.6 micrograms per cubic metre, compared with 772.9 in 2021.

Hourly averages reached 1,763 micrograms per cubic metre at Nehru Nagar and 1,710 at Anand Vihar. These hourly peaks are not directly comparable with a 24-hour air-quality standard, but they show how sharply pollution can rise over a short period.

Does this prove that green crackers failed? Not entirely. The figures show that severe pollution spikes can occur even when they are permitted. They do not establish that fireworks alone caused the entire deterioration or that conventional crackers would have produced the same outcome.

Why Can Delhi's Air Still Deteriorate Despite Lower-Emission Crackers?

Three factors help explain the problem.

The number of crackers matters. Millions of products releasing fewer emissions individually can still generate substantial pollution when used together.

Weather matters. Low wind speeds and conditions that limit atmospheric dispersion can trap pollutants close to the ground. The same quantity of emissions can have different effects under different weather conditions.

Existing emissions matter. Traffic, industries, construction dust and other sources already contribute to Delhi's poor air quality. Fireworks add to this existing burden.

This is why lower emissions per cracker should not be confused with cleaner city-wide air. Reducing the total number of fireworks used can also reduce the overall emissions they generate.

What Has the Supreme Court Decided About Green Crackers in 2026?

The legal debate has moved towards regulating specified products rather than treating every firecracker as identical.

On September 30, 2026, the Supreme Court accepted a proposal to permit specified next-generation joined crackers, subject to technical conditions. According to the government's submissions, these redesigned products burst around five braids per second, compared with approximately 25 for conventional joined crackers.

The conditions cover approved formulations, licensed manufacturers, safety and emission standards, testing, certification and product identification. The decision does not amount to unrestricted permission for all joined crackers.

The environmental impact of barium-containing formulations remained under scrutiny, with outdoor testing scheduled before a further hearing on October 15.

Read the Supreme Court's September 30 order in Arjun Gopal v. Union of India for the technical conditions and outstanding questions.

Important: The final order following the October 15 hearing and the latest Delhi-NCR restrictions should be verified before publication. The September order alone does not settle every restriction applicable to the region.

How Can Consumers Identify Genuine Green Crackers?

Green logos and QR codes are intended to help consumers identify compliant products, but packaging claims should not be accepted blindly.

Buy only from authorised sellers where their sale and use are permitted. Check the prescribed identification and certification details, avoid unverified products, and follow the latest local restrictions.

The bigger lesson is simple: certification and enforcement matter as much as the technology itself.

Are Green Firecrackers a Solution or Just Another Diwali Myth?

The science does support the idea that certain formulations can reduce emissions compared with conventional alternatives. That makes green crackers a potentially useful step towards less polluting celebrations.

But they are not harmless, and they cannot solve Delhi's air-quality problem on their own. Their real-world impact depends on product compliance, the number used, atmospheric conditions and effective enforcement.

The bottom line: Green crackers can mean fewer emissions, not zero emissions. Cleaner celebrations will require verified products where permitted, responsible use and a reduction in the total pollution generated.