After SC order, focus is on chemicals in firecrackers

Aluminium powder, sulphur and potassium nitrate go into noise-making crackers, while barium nitrate (green) and strontium nitrate (red) emit light.   | Photo Credit: AP

The Supreme Court ban on the use of antimony, lithium, mercury, arsenic and lead in the manufacture of firecrackers to prevent air pollution has turned the focus on what chemicals are used to produce spectacular visual effects and noise.

The Tamil Nadu Fireworks and Amorces Manufacturers’ Association, which produces most of the fireworks in the country, says none of the specific products banned by the court are used.

A Supreme Court Bench of Justices Madan B. Lokur and Deepak Gupta had on July 31, in an order, directed that no firecrackers manufactured by the respondents shall contain the chemicals in any form, whatsoever. The court entrusted the Petroleum and Explosive Safety Organisation (PESO) with the responsibility of ensuring compliance particularly in Sivakasi. Over 90% of cracker production is done in Sivakasi.

Claim denied

Incidentally, the court also noted it appeared that no standards have been laid down by the Central Pollution Control Board (CPCB) with regard to air pollution caused by the bursting of firecrackers.


However, cracker manufacturers in Sivakasi, who denied using the banned chemicals, said the sound and light show is produced by chemicals such as sulphur, aluminium powder and charcoal (used as fuel), besides potassium nitrate and barium nitrate (as oxidising agents), the industry says.

Aluminium powder, sulphur and potassium nitrate go into noise-making crackers, while barium nitrate (green) and strontium nitrate (red) emit light. Aluminium powder is used in sparklers. “A combination of barium nitrate and strontium nitrate in varying proportions produces different colours,” Tamil Nadu Fireworks and Amorces Manufacturers’ Association secretary K. Mariappan said.

AntimonyAntimony sulphides are used in the production of the heads of safety matches, military ammunition, explosives and fireworks.Risks: The elemental antimony metal does not affect human and environmental health. Inhalation of antimony trioxide (and similar poorly soluble sulphides of antimony) is considered harmful and suspected of causing cancer.
MercuryA mercury compound called "Mercury(II) fulminate" is a primary explosive It is extremely sensitive to friction, heat and shock and is mainly used as a trigger for other explosives in percussion caps and blasting caps.
ArsenicArsenic is generally non-combustible. But certain compounds of arsenic are highly explosive and figure on the health hazard lists of several countries and thinktanks. Arsine, for instance, is  a flammable, pyrophoric, and highly toxic gas while being one of the simplest compounds of arsenic. Arsine is used as an agent in chemical warfare, thus several countries have regulations on its use owing to its highly inflammable nature.
Lead The most common primary explosives are lead azide and lead styphnate, compounds of lead found in most heavy grade explosives. Due to its explosive nature, lead azide is used in most detonators to initiate big explosions. Lead styphnate is also an explosive used as a component in primer and detonator mixtures for less sensitive secondary explosives
LithiumA highly volatile element, lithium is flammable, and it is potentially explosive when exposed to air and especially to water, though less so than other alkali metals

Doubt over strontium

Significantly, the Supreme Court, observed that there seems to be some doubt about strontium and its compound used in crackers, and has posted the case to August 23 to hear submissions about the use of strontium.

Mr. Mariappan said that phosphorous and chlorate are not allowed to be used in fireworks. Potassium chlorate and potassium perchlorate are friction-sensitive and accident-prone, if used in combination with sulphur. Hence, it is not a part of fireworks chemistry. “Chinese crackers, which use chlorate are, therefore, banned in India,” the association’s representative said. However, chlorate and phosphorus are used by Amorces manufacturers for making exploding ‘caps’ and rolls. Similarly, red phosphorous and pitch are used in making of ‘snake eggs’.

“We were using red lead for crackers emitting red colour light. However, as per PESO’s advise, we switched to bismuth oxide some 15 years ago, as we were told that red lead hangs in the atmosphere causing pollution,” he said.

Where do the chemicals for the firecracker industry come from? Sources in the industry and the PESO claim that the chemicals are domestically procured. “Fireworks manufacturers are also involved in aluminium powder production and they supply the entire industry’s requirement,” he added.


But a PESO source said the procurement of raw materials for fireworks does not come under the purview of the Explosives Act. The PESO has been testing samples of crackers only for adherence to the sound limit of 125 decibels at a distance of four metres.

What gives colour to the firecrackers?

RedStrontium salts (Nitrates, carbonates and sulphates of strontium)
OrangeCalcium salts (Carbonates, chlorides and sulphates of calcium)
YellowSodium salts ( Nitrates and oxalates of sodium)
GreenBarium salts (Nitrates, carbonates, chlorides and chlorates of barium)
BlueCopper salts (Carbonates and oxides of copper)
PurpleA combination of copper and strontium compounds
Whitehe burning of metals like magnesium, aluminium and titanium)


(With inputs from Delhi Bureau)

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Printable version | Apr 16, 2021 7:29:03 PM |

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