Why it is in news?

• The Punjab and Haryana High Court y took suo motu cognisance of deteriorating air quality and asked the States of Punjab and Haryana and the Union Territory of Chandigarh to submit details of licences to sell firecrackers.
• This came days after the Supreme Court banned firecrackers in Delhi and the national capital region.
• The High Court asked the authorities for details of permanent as well as temporary licences. 

Why was it is in news earlier?

• The Supreme Court banned firecrackers in Delhi and the national capital region.
• Citing toxins in the air, Supreme Court has banned the sale of firecrackers in Delhi-NCR this Diwali.

EPCA submission

• In November 2016 a great smog enveloped Delhi for days after Diwali
• The Environment Pollution (Prevention & Control) Authority (EPCA) told the Supreme Court that the capital’s terrible air quality had been “compounded” by the burning of firecrackers.
• The EPCA is the pollution watchdog that the central government created for the National Capital Region, based on a 1998 order of the Supreme Court.

Chemistry of fireworks

1. How a specific exploding firework performs depends on how its four primary ingredients — oxidiser, fuel, colouring agents, and binder — combine.
2. Burning requires oxygen — the oxidisers in fireworks are chemicals that release oxygen to allow the explosion to take place. Nitrates, chlorates and perchlorates are used most commonly.
3.  Fires need fuel to burn; the commonest fuel in Indian fireworks is charcoal. The combination of fuel and oxidiser — or gunpowder — causes the explosion.
4. Colouring agents are chemical compounds that give fireworks their colour.
5.  Aluminium compounds produce brilliant whites, barium nitrate produces greens, and the addition of copper results in blue light.
6. metals (like aluminium, titanium, copper, strontium, barium etc are added to regulate the speed of the chemical reaction
7. In the case of a rocket, the combination of fuel and oxidisers, or gunpowder, propels the firework upwards

How firecrackers impact health

• Studies in Europe, Canada and China have found links between increases in the concentration of fireworks, and variations in air quality.
•  The European Respiratory Society says all fireworks contain carbon and sulphur — which are necessary for burning — apart from a wide range of chemical compounds.
• Adults exposed to high levels of ambient air pollution have shown increased prevalence of chronic cough, phlegm, and breathlessness
• Cause an increased risk of developing respiratory symptoms, asthma, chronic obstructive pulmonary disease, allergic rhinitis, lower respiratory tract infections, and lung cancers.
• Another report found that children were susceptible in particular, since their defences against particulate matter and other gaseous air pollutants were weaker. 

Existing guidelines

• The CPCB affidavit refers to four types of explosive firecrackers — atom bombs, chinese crackers, garland crackers and maroons — for which guidelines exist
• According to these guidelines, the sulphur content must not exceed 20%, nitrates 57%, and aluminium powder contents, 24%. The guidelines were silent on heavy metals such as cobalt, copper and magnesium, extremely toxic compounds of which are widely used as colouring or regulating agents.