What Makes Green Crackers Different and Are They Truly Less Polluting?

Green crackers are modified fireworks developed by CSIR-NEERI that use smaller shells, fewer raw materials, and additives (dust suppressants) to cut emissions. Though better, they are not pollution-free.

The Supreme Court has ruled that people in Delhi and the National Capital Region (NCR) can burst firecrackers only during fixed time slots, from 6 am to 7 am and again from 8 pm to 10 pm. The Court also made it clear that only green crackers will be allowed and their sale and bursting will be permitted strictly at designated locations to control pollution and ensure proper enforcement. So what is a green cracker and is it truly less polluting? Read on to find out:

A green cracker (also called a reduced emission firecracker) is a fireworks product engineered to produce lower levels of harmful emissions compared to conventional fireworks. The concept was developed by CSIR-NEERI (National Environmental Engineering Research Institute) and allied labs in India, responding to public health and air quality concerns during festivals like Diwali.

Green crackers achieve this by:

• Reducing the shell size and quantity of material used
• Avoiding or minimising ash-forming substances
• Using additives (dust suppressants) like zeolites, clays, silica, or aluminium oxides that help trap particulates
• Lowering or eliminating certain chemical oxidisers or colourants (for example, reducing barium compounds) 

Maintaining performance in sound and effect, ideally matching the sensory experience of conventional crackers while emitting less pollution. In terms of quantifiable goals, the NEERI definition aims for:

• At least 30 % reduction in particulate matter (PM) emissions
• At least 20 % reduction in gaseous emissions (e.g. NO₂, SO₂) with another 10% reduction among other gases (so a total of ~30 % gas emission reduction)
• All reductions compared to conventional crackers of the same category.
• Some green crackers (especially those using peroxide or water-based technologies) can reportedly achieve even higher PM reduction (over 80 % under lab settings)
• Green crackers are supposed to carry a CSIR-NEERI green logo and a QR code, which can be scanned (using the 'CSIR NEERI Green QR Code' app) to verify authenticity and emissions certification.

How do conventional firecrackers work and what's the problem?

Conventional firecrackers use a mix of:

• Fuel (often charcoal, sulfur, or other reducing agents)
• Oxidising agents (nitrates, chlorates, perchlorates)
• Colourants / regulators / metal salts (e.g. strontium, barium, copper, sodium, calcium, etc.)
• Binders (e.g. dextrin, starch)

On explosion or burning:

• A large amount of particulate matter (PM₂.₅, PM₁₀, even ultrafine particles) is released
• Gaseous pollutants like sulphur dioxide (SO₂) and nitrogen oxides (NOₓ) are formed
• Heavy metals (for colour effects) may become part of the particulate load
• The ash, unburnt residues and byproducts contribute to local pollution

These emissions, especially during festival seasons like Diwali when many fireworks are burst in a short interval, can spike pollution levels dramatically in cities, deteriorating air quality and posing health risks.

What exactly changes in green vs conventional: The technical differences

The differences between conventional and green firecrackers are quite clear. Here’s how they vary in their composition and impact:

Shell size and material load: Conventional firecrackers have full-sized shells and use a larger quantity of raw materials. In contrast, green crackers are made with smaller shells and less raw material, which directly helps reduce emissions.

Ash-forming substances: Traditional firecrackers use more ash-producing materials. Green crackers, however, eliminate or greatly reduce such substances, leading to cleaner combustion and less residue.

Use of barium and heavy metal colourants: Conventional fireworks often rely on barium nitrate and other heavy metals to produce bright colours, especially green. Green crackers either minimise or completely remove these compounds. Studies have shown that green versions can reduce barium levels in emissions by 30-60 per cent.

Additives for emission suppression: Regular firecrackers rarely use additives to control pollution. Green crackers include dust suppressants such as zeolite, clay, or silica, which help trap fine particles and cut down on airborne pollutants.

Emission reduction goals: Green crackers are designed to achieve about 30 per cent reduction in particulate matter (PM) and 20–30 per cent reduction in gaseous emissions such as sulphur dioxide (SO₂) and nitrogen oxides (NOₓ) when compared to conventional ones.

Sound output and sensory effect: Many conventional fireworks are very loud. Green crackers are designed to maintain similar sound and visual effects (around 100-120 decibels) while limiting their toxic emissions, so the celebratory feel is preserved.

Certification and identification: Ordinary firecrackers have no special certification. Authentic green crackers must carry the CSIR-NEERI “Green Crackers” logo and a scannable QR code that verifies they have passed emission testing.

Manufacturing and oversight: Conventional firecrackers are often made without strict regulation of chemical mixtures. Green crackers, on the other hand, are tested and approved by CSIR-NEERI and the Petroleum and Explosives Safety Organisation (PESO) before production and sale.

These changes make green crackers cleaner and relatively safer for the environment, though experts emphasise they still release some pollutants and should be used responsibly.

What are the limits and caveats?

While green crackers are a step forward, they are not perfect or totally 'safe'. Some caveats:

• The emission reductions are measured in controlled conditions. Real-world effects may be lower, especially with misuse, mixing of different crackers, or non-compliance.
• In winter or trapped atmospheric conditions, even the reduced emissions may still worsen air quality severely.
• Some studies suggest green crackers may still emit ultrafine particles (PM₁ or below), which are harder to filter and more harmful since they penetrate deep into lungs and bloodstream.
• Verification systems (brands, QR codes) have been compromised with fake tags, counterfeit logos, faulty QR codes, making enforcement a challenge.
• Only certain categories of crackers are permitted as green crackers (flower pots, sparklers, maroons, chakkars etc.). More complex display fireworks may not yet have green versions.

The sound (noise) might still be high, and some green crackers may not reduce noise significantly.

Supreme Court's nod to green crackers in Delhi-NCR

The Supreme Court has recently approved the use of green crackers in Delhi and the NCR between 6 pm and 10 pm, as a balance between cultural celebrations and pollution control.

This window aims to restrict the bursting period and to ensure that only certified green crackers are used, rather than unrestricted use of conventional ones. Enforcement will need:

• Strict monitoring of sale of only certified crackers
• Validation via QR codes and monitoring agencies
• Crackdown on non-compliant or counterfeit firecrackers
• Public awareness so people buy only authentic green ones

In the end, green crackers are not a full solution. They are a compromise: better than nothing, but not ideal. Long term, reducing or banning fireworks, promoting community displays or developing truly zero-emission alternatives may be needed.