The apex court sought to know which chemicals should not be used beyond a limit in the firecrackers and observed that guidelines on this have to be laid down.
"Somebody should tell us that firecrackers should not have chemicals like chlorine, potassium and titanium beyond a limit of say 5 per cent," a bench comprising Justices Madan B Lokur and Deepak Gupta said.
The bench said there were firecrackers which emitted sound, while there were others which emitted light and smoke.
The firecracker manufacturers told the bench that they were using chemicals which were within the prescribed limits and not at all hazardous.
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They claimed they were facing serious consequences due to the apex court order banning the sale and stockpiling of firecrackers in the national capital region (NCR).
The scientists from Central Pollution Control Board (CPCB) and the Petroleum and Explosives Safety Organisation (PESO) also elaborated in the court on the effects of pollution from firecrackers.
The apex court had in November last year directed the Centre to suspend all licences permitting wholesale and retail sale of fireworks within the NCR territory and said the suspension shall remain in force till further orders. It had also directed that no such licences shall be granted or renewed till further orders.
The petitioner also referred to the pollution from firecrackers during Diwali.
The PESO counsel said that CPCB was the body to set standards for pollution and it would give its full support in formulating guidelines on the issue.
The apex court had earlier pulled up the CPCB and PESO for "lack of clarity" on environmental impact of pollution from firecrackers.
It had expressed concern over air pollution in Delhi-NCR, especially from crackers during the festive season of Diwali and Dussehra, and said the authorities have to take steps to regulate firecracker industries.
It had also directed CPCB to prepare an inventory of existing firecrackers with the traders and suggest measures for their disposal.
CPCB had earlier told the court that chemical composition of firecrackers which are commonly used exceeded some of the prescribed parameters which may have harmful effects.
The board, in its report, had said that most of the firecrackers carried large amount of sulphur which was one of the major causes of air pollution.