Question

Number of Ozone Depleters identified by the Montreal Protocol(1987) was
(a)12
(b)8
(c)6
(d)4

Answer 1

The Montreal Protocol on Substances that Deplete the ozonosphere, also known simply as the Montreal Protocol, is a world treaty designed to protect the ozone layer by phasing out the production of various substances that are responsible for ozone depletion.

Complete answer:
The Montreal Protocol on Substances that Deplete the Ozone, 1987 was meant to protect the ozone depletion by gradually phasing out the major ozone-depleting substances. This protocol was signed to the Vienna Convention and identifies the following as ODS:
Chlorofluorocarbon($\mathrm{CFC}$)
Halons
Carbon tetrachloride($\mathrm{CCl_4}$)
Hydrochlorofluorocarbon($\mathrm{HCFC}$)
Hydrobromofluorocarbons($\mathrm{HBFC}$)
Bromomethane($\mathrm{CH_3Br}$)
Bromochloromethane($\mathrm{CH_2BrCl}$)
Hydrofluorocarbons($\mathrm{HFC}$)
Hence the Ozone depleters identified by the Montreal Protocol are 8.

Additional Information: The Montreal Protocol on Substances that Deplete the ozonosphere (the Montreal Protocol) is a world agreement made in 1987. It was designed to stop the production and import of ozone-depleting substances and reduce their concentration in the atmosphere to help protect the earth's ozone layer.

The Montreal Protocol sits under the Vienna Convention for the Protection of the Ozone Layer (the Vienna Convention). The Vienna Convention was Taken into action in 1985 following international discussion of scientific discoveries within the 1970s and 1980s highlighting the adverse effect of the act on ozone levels in the stratosphere and the discovery of the ‘ozone hole’. Its objectives are to promote cooperation on the adverse effects of human activities on the ozone layer.The Montreal Protocol is widely considered as the most successful environment protection agreement.

So, the correct answer is,”8”.

Note: Damage to the Earth’s protective ozone layer has sparked unprecedented worldwide concern and action. Since it was agreed internationally in 1987 to phase out ozone-depleting substances, 197 countries have ratified the Montreal Protocol. In January 2012, South Sudan approved the Montreal Protocol, making it the first international environmental treaty to achieve complete approval, a truly remarkable effort that reflects the universal acceptance and success of the agreement.