DELHI: With the Supreme Court allowing the bursting of green firecrackers between 6am and 7am and 8pm and 10pm on November 7 and 8, TOI’s Priyangi Agarwal explains how they differ from conventional fireworks and whether they can help ensure a cleaner Diwali.Green crackers are low-emission firecrackers designed to produce significantly less air and noise pollution than conventional fireworks. They aim to achieve a minimum 30% reduction in particulate matter (PM) emissions and at least 10% reduction in gaseous emissions. They are also designed to generate noise levels of less than 125 decibels at a distance of four metres from the point of bursting.However, green crackers may not be entirely pollution-free. A study by Delhi Technological University found that green crackers produce high concentrations of ultrafine particles, which are more dangerous than PM2.5 and PM10.How green crackers differ from conventional fireworksThe composition of conventional and green crackers differs significantly. Conventional crackers contain 34% aluminium, 57% potassium nitrate and 9% sulphur.Green crackers, on the other hand, contain 29% aluminium, 28% potassium nitrate, 38% CSIR-NEERI’s proprietary material (Fe₂O₃) and 5% sulphur.Green crackers offer several emission-related benefits, including a 14% reduction in aluminium usage, 44% reduction in sulphur, 50% reduction in potassium nitrate and 30% reduction in PM emissions.The cost of flash powder used in conventional crackers is ₹132 per kg, compared with ₹95 per kg for green crackers.
Chemicals banned in green crackersGreen crackers are manufactured without certain chemicals that are used in conventional fireworks. These include barium nitrate (Ba(NO₃)₂), lithium (Li), mercury (Hg), arsenic (As) and cadmium (Cd).To help consumers identify them, green crackers carry a green logo of CSIR-NEERI and PESO, along with encrypted QR codes.
Conventional crackers and particulate pollutionConventional firecrackers can generate high levels of PM2.5 emissions. Measurements recorded within 1–6 feet of bursting showed PM2.5 concentrations of 64,500 µg/m³ for a snake tablet, 38,450 µg/m³ for a garland (ladl of 1,000), 28,950 µg/m³ for a pulpul, 10,390 µg/m³ for sparklers (fullhand), 9,490 µg/m³ for a ground spinner (chakri) and 4,860 µg/m³ for a flower pot (anar).Delhi’s firecracker ban and pollution levelsDelhi has witnessed several restrictions on firecrackers over the years, with pollution levels continuing to remain a concern around Diwali.In 2015, when no firecracker ban was in place, pollution readings recorded on November 10, 11 and 12 were 353, 343 and 360, respectively.In 2016, when there was no firecracker ban, the readings on October 29, 30 and 31 were 404, 431 and 445.In 2017, the Supreme Court banned the sale of firecrackers for the first time in Delhi. The readings on October 18, 19 and 20 were 302, 319 and 403.In 2018, the Supreme Court imposed a nationwide ban on crackers while allowing only green crackers. The readings on November 6, 7 and 8 were 338, 281 and 390.In 2019, only green crackers were allowed in Delhi within an 8pm to 10pm window. The readings on October 26, 27 and 28 were 287, 337 and 368.In 2020, a complete ban was imposed on all kinds of firecrackers in the NCR, but it was widely flouted. The readings on November 13, 14 and 15 were 339, 414 and 435.In 2021, a complete ban on all kinds of firecrackers was imposed in Delhi, but it was flouted. The readings on November 3, 4 and 5 were 314, 382 and 462.In 2022, a complete ban on all kinds of firecrackers was imposed, but it was flouted in Delhi. The readings on October 23, 24 and 25 were 259, 312 and 303.In 2023, a complete ban on all kinds of firecrackers was imposed, but it was flouted in Delhi. The readings on November 11, 12 and 13 were 220, 218 and 358.In 2024, a complete ban on all kinds of firecrackers was imposed, but it was flouted in Delhi. The readings on October 30, 31 and November 1 were 307, 328 and 339.In 2025, only green crackers were allowed between 6am and 7am and 8pm and 10pm, but the restrictions were widely flouted. The readings on October 19, 20 and 21 were 296, 345 and 351.