Diwali fireworks are a cherished cultural tradition across India, but they are also a predictable annual spike in air and noise pollution. “Green crackers” were developed as a lower-emission alternative: the idea is to reformulate fireworks so they release fewer toxic metals, lower particulate mass, and less noise — while preserving the festive spectacle. But how green are they, chemically and in practice? And do they actually make a meaningful difference to air quality? Here’s a concise, evidence-based look. Press Information Bureau+1
What are “green crackers”?
“Green crackers” (also called improved or reduced-emission crackers) are firework formulations developed and standardized in India under coordination by CSIR-NEERI and other CSIR labs. They are manufactured using alternative raw materials, altered shell sizes and additives that are intended to reduce particulate emissions, gaseous pollutants and noise compared to conventional crackers. Certified green crackers carry NEERI/CSIR certification marks and QR codes to indicate the approved formulations. Press Information Bureau+1
Basic chemistry — what’s changed?
Traditional crackers rely on oxidizers, fuels and metal salts to produce colours, sparks and sound. Some of the common problematic ingredients in older formulations include barium and certain heavy-metal salts (used for green colours), and excess aluminium or magnesium (which increase bright white emission and particulate load). Green cracker formulations attempt one or more of the following:
- Reduce or eliminate barium salts and other toxic metal salts (a big target of regulatory action). Press Information Bureau+1
- Reduce the use of aluminium and similar metals (some green variants are called “Safe Minimal Aluminium” — SAFAL). vajiramandravi.s3.us-east-1.amazonaws.com
- Use alternative oxidizers, binders or “dust-suppressant” additives (e.g., formulations that produce more water vapour on combustion so some particles are temporarily diluted or agglomerate). Press Information Bureau+1
- Smaller shells and reduced raw-material loading (less explosive mass per unit → lower total emissions per cracker). Press Information Bureau
Note: exact formulations are often proprietary or under controlled distribution by NEERI; manufacturers who produce NEERI-approved crackers typically sign agreements to follow the approved recipes. India Today
How much pollution do green crackers produce — mass vs particle number
Two important ways scientists measure air pollution from fireworks are:
- Mass concentrations (PM2.5 / PM10 — the mass of particulate matter per cubic metre).
- Particle number and size distribution (ultrafine particles, UFPs, which have small mass but high number and can penetrate deep into the lungs).
Evidence on mass (PM2.5 / PM10)
Laboratory tests and field assessments reported by NEERI and government briefings indicate that green cracker formulations can reduce mass-based particulate emissions by roughly 15–30% compared with some conventional formulations (figures vary by cracker type and testing conditions). This is the origin of the commonly-quoted “~30% lower emissions” claim. However, these are relative reductions per cracker, not elimination of emissions. If large numbers of crackers are burst, the aggregate PM load can still be substantial. Press Information Bureau+1
Evidence on particle number and ultrafine particles
Recent peer-reviewed measurements show a more nuanced picture: some studies report that green crackers may emit a higher fraction of ultrafine particles (very small particles by diameter) even while lowering mass emissions. Ultrafine particles have small mass but high number and are implicated in acute cardiopulmonary effects because they penetrate deep into the lungs and may translocate to the bloodstream. In short: green crackers may lower mass (PM2.5) but not necessarily the most biologically active particle exposures — and in some cases they may increase particle counts in the UFP size range. ScienceDirect+1
Gases and toxic metals
Because green crackers aim to exclude or reduce barium and other heavy-metal salts, the emissions of certain toxic metals can be lower from certified formulations. Likewise, by reducing combustible carbon or sulfur content, emissions of gaseous products like SO₂ or some VOCs may be reduced. But again — reductions are proportional to how faithfully the approved formulations are used and the total amount of crackers consumed. Down To Earth+1
Regulation and the legal story (ban / relax / certification)
- October 2018 (Supreme Court direction): The Apex Court directed a ban on barium salts and prohibited “joined crackers”; it allowed reduced-emission (improved/green) crackers under certification/controls. NEERI/CSIR were tasked with R&D and standardisation. The Indian Express+1
- NEERI/CSIR development and launch (2019 onwards): CSIR-NEERI developed prototypes and a certification system (green logo + QR code) to identify genuine green crackers. The government launched the concept officially and named approved variants such as SWAS, STAR and SAFAL. Press Information Bureau+1
- State/tribunal measures: Some courts/tribunals (including NGT rulings, state authorities) have at times restricted or banned firecracker use in particular zones (e.g., complete bans in some years for NCR), while the Supreme Court’s technical directions continue to be used as the national framework. In practice, enforcement, counterfeit products and online sales restrictions have complicated outcomes; regulators use QR codes and certification lists to try to control fake labeling. Recent court and administrative decisions around limited sale/use of certified green crackers during specific time slots reflect this balancing act. Central Pollution Control Board+2ThePrint+2
Bottom line — do green crackers “solve” the pollution problem?
No. They reduce some emissions per cracker (mass of PM and some metal salts) but do not eliminate emissions or health risks. Important caveats:
- Percent reductions are per-cracker and variable (15–30% mass reduction is often cited) — but aggregate pollution depends on how many crackers are used. If cracker usage increases because people think green crackers are “safe”, air quality gains may be nullified. The Economic Times+1
- Ultrafine particle concerns: studies show green crackers can emit a higher fraction of ultrafine particles, which may be more harmful than their mass would indicate. ScienceDirect+1
- Implementation issues: counterfeit labeling, weak enforcement, and inconsistent manufacturing quality have limited real-world benefits in some areas. QR code systems and certification lists help, but are not foolproof. The Times of India+1
Practical recommendations
For individuals:
- If you choose to use fireworks, favour certified green crackers (look for the NEERI/CSIR logo and valid QR code), restrict bursting to small quantities and follow local time bans and safety rules. neeri.res.in+1
- Consider non-combustion celebrations (laser/light shows, community-organised low-noise displays, or “digital crackers”) to protect children, elderly and people with respiratory illness. ResearchGate
For policymakers and public health planners:
- Treat green crackers as harm-reduction, not a complete solution. Combine certification with strict enforcement, public education, and promotion of alternatives. science.thewire.in
- Invest in real-time monitoring around festivals, public guidance based on meteorology, and stricter control of counterfeit products and cross-state/online sales. ThePrint+1
- PIB / Government launch: “India launches Green Crackers” (Press Information Bureau). Press Information Bureau
- CSIR-NEERI: Green Crackers (official NEERI page and manufacturer list). neeri.res.in
- CPCB / technical documents on permitted crackers and testing/standards. Central Pollution Control Board
- Yadav S.K. et al. — measurements showing particle size/number concerns for green crackers (particle number/size studies). ScienceDirect
- Recent reporting & analysis on regulatory decisions, enforcement and the 30%-reduction claim: Times of India / Indian Express / Economic Times analyses. www.ndtv.com+2The Times of India+2
