Green crackers with 30 per cent less emissions are now available in the market, Union minister Harsh Vardhan announced ahead of Diwali, noting that the step will take care of people’s sentiments and address pollution concerns. The minister said they have been introduced to deal with the menace of pollution and would help the fireworks industry, which was facing closure after the Supreme Court in 2018 banned conventional firecrackers that have high emission levels and allowed only those that conform to permissible smoke and noise levels.

Background

* In October 2018, the Supreme Court had ruled that only “green firecrackers” having low emission and permissible sound limits were to be sold and used. It had also fixed a timeslot for fireworks between 8 pm and 10 pm on Diwali, and between 11.45 pm and 12.30 am on Christmas Eve and New Year.

* This decision followed a complete ban on the sale of firecrackers in Delhi by the Supreme Court in November 2016 after the national capital witnessed a serious episode of smog, described by the Centre for Science and Environment as the worst in 17 years.

* This year, on October 5, in a bid to combat air pollution, the Union Ministry of Science and Technology launched environment-friendly firecrackers developed by the Council of Scientific and Industrial Research (CSIR) laboratories.

* CSIR-NEERI developed new formulations for reduced emission light and sound emitting crackers (SWAS, SAFAL, STAR) with 30 per cent reduction in particulate matter using potassium nitrate (KNO3) as oxidant.

* SWAS stands for safe water releaser, SAFAL stands for safe minimal aluminum and STAR stands for safe thermite cracker.

* These crackers are 15-20 per cent cheaper than conventional ones. STAR eliminates the usage of potassium nitrate and sulphur. SAFAL has less usage of aluminum as compared to commercial crackers.

* The firecrackers have a unique property of releasing water vapour.

* Researchers at CECRI have developed green crackers by modifying the chemical formulations for flower pots, ‘jiljil’ and used flower pots as a substitution for barium nitrate.

What is particulate matter?

* Particulate matter is a mixture of solid particles and liquid droplets suspended in the air. These include PM10, which are particles with a diameter equal to or less than 10 micrometres, and PM2.5 that are of diameter equal to or less than 2.5 micrometres.

* Numerous studies have linked particulate pollution exposure to many health problems, including premature death in people with heart or lung diseases. They can also settle on ground or water and, depending upon their chemical composition, may have an adverse impact on them.

Can conventional crackers be tweaked?

They could and have been modified. Apart from ‘green crackers’, there are other formulations based on new oxidisers, fuel and additives - singly or in combination - which have managed to reduce PM10 and PM2.5 emissions by more than 50 per cent. These are being tested at present, and are showing encouraging results.

How do ‘green crackers’ work?

* Dr Sadhana Rayalu, chief scientist and head of NEERI’s Environment Materials Division (EMD), said the firecrackers use a proprietary additive that acts as a dust suppressant. The usage of chemicals is less in green crackers. The total quantity is being maintained by using CSIR proprietary additive, which on fragmentation releases dust suppressants.

* Some of the ‘green crackers’ have also replaced barium nitrate as an oxidiser for combustion. Barium nitrate is injurious to health when inhaled, causing irritation in the nose, throat and lungs. High exposure to barium nitrate can also cause nausea and irregular heartbeat.

* Among the new firecrackers developed are environment-friendly versions of traditional anar, chakri, sparklers and other light-sound emitting firecrackers. According to NEERI, these exploit the exothermic heat of materials such as zeolite, clay and silica gel for burning, and also match the performance of commercial firecrackers in terms of sound.

How can a ‘green cracker’ be identified?

Union Minister Dr Harsh Vardhan said a QR code will be printed on the firecrackers to differentiate them from conventional ones. He has also said the cost of these firecrackers would be the same as conventional ones, and that they are already available in the market.

How are ‘green crackers’ produced?

* Under the current framework, the composition of firecrackers is disclosed to manufacturers after signing a Memorandum of Understanding and a non-disclosure agreement. Following this, manufacturers have to apply to the Petroleum and Explosives Safety Organisation (PESO) for authorisation.

* The samples thus produced are submitted to CSIR for emission testing. Nearly 165 fireworks manufacturers had been roped in for production.