Climate & Environment

Green Firecrackers Fail to Reduce Delhi’s Diwali Air Pollution

By Jasjeev Gandhiok

Even though green firecrackers emit less than conventional ones, they are not pollution‑free and did little to improve Delhi’s air quality this Diwali. The Supreme Court had allowed green firecrackers in the National Capital Region between 6 am and 7 am and 8 pm and 10 pm for two days before Diwali, but fireworks continued well past midnight when a complete ban took effect. The burst of crackers added to an already hazardous air‑quality situation, leaving neighbourhoods shrouded in thick haze.

Experts say the lack of on‑ground monitoring makes it hard to distinguish green from conventional crackers. Sunil Dahiya, founder and lead analyst at Envirocatalysts, noted that sulphur dioxide (SO₂), a clear indicator of firecracker emissions, rose sharply the day before Diwali. He said SO₂ increased by about 40 % across the city that night, after staying flat the nights before. Dahiya added that hourly, city‑wide PM₂.₅ levels peaked at nearly 600 µg/m³ around 1 am, more than ten times the 24‑hour standard of 60 µg/m³.

“Green firecrackers are meant to emit only about 30 % less than conventional ones, and 30 % less of a very large amount is still a very large amount,” Dahiya said. He called for an end to firecracker bursting during festivals and stronger action against other pollution sources.

IIT Delhi professor Mukesh Khare said that while green firecrackers can lower peak pollution levels, ensuring only they are sold and used remains a major challenge. “Our distribution network is poor, with not enough outlets with green firecrackers. This allows conventional crackers to flood the markets and there are no checks and balances on the ground,” he said.

In 2018 the Supreme Court banned barium salts, which colour the flame green and supply oxygen for the fuel, and allowed only “improved” and “green” firecrackers without barium salts. CSIR‑NEERI developed the first designs in October 2018, including SWAS, which dropped potassium nitrate and sulphur. The government said the designs cut particulate matter by 30‑40 %. The court expected green firecrackers to cut PM₂.₅ emissions by at least 25‑30 %. However, green firecrackers still burn metal salts for their colours, and the claimed cuts apply only to particulate matter.

Green firecrackers developed after the 2018 court order replaced barium nitrate with zeolites, reduced aluminium content, and added dust suppressants. CSIR‑NEERI claims these modifications cut emissions by 30‑35 % compared to traditional firecrackers. Experts say the reduction is still negligible: green firecrackers emit 65‑70 % of traditional firecracker pollution, producing substantial particulate matter, SO₂ and nitrogen oxides.

Environmental activist Bhavreen Kandhari, who has reported illegal firecracker use to the Delhi Police, blamed the lack of will among authorities for making restrictions largely meaningless. “No one is checking whether these are green firecrackers or conventional ones. Green firecrackers also pollute an overly saturated air in Delhi, when meteorological conditions are highly unfavourable,” she said.

The court’s directions included product‑specific QR codes on green cracker boxes, designated sale locations and police patrol teams to prevent the sale and use of conventional crackers. The scale of the problem and the absence of effective verification on the ground continued to undermine enforcement.

Delhi had a complete ban on all firecrackers between 2020 and 2024, but restrictions were widely flouted. Green crackers were permitted in 2025, and the latest relaxation has again exposed the difficulty of translating restrictions into compliance. Residents said the prolonged bursting of firecrackers well past midnight made an already difficult pollution situation worse, with elderly people forced to remain indoors.

“Green or non‑green, how can bursting firecrackers be permitted in a city reeling under hazardous air pollution and an acute public health emergency?” asked BS Vohra, head of the East Delhi RWA forum. He added that the time restriction was clearly not followed or enforced.

Swagata Dey, policy specialist at the Centre for Study of Science, Technology and Policy, said green firecrackers were formulated to produce relatively lower emissions, but questions remained over their quality control at scale. “Green firecrackers are lab‑tested in small batches, with no proven quality control at scale, and they still produce smoke,” she said. She noted that implementing pollution‑related bans can be challenging owing to the scale of the population and enforcement constraints. Although conventional firecrackers have been banned in NCR for almost five years, ensuring compliance has been difficult.