What were countries to do if they signed the Montreal Protocol?

Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs) are among the substances that are causing the hole in the ozone layer; countries that signed the Montreal Protocol on Substances that Deplete the Ozone Layer were required to reduce and cease using these substances.

When the developed world signed the Montreal Protocol in 1987, it was mandated that the production of the chemicals listed above be reduced by 80% from 1986 levels to 1989 levels, and then by 50% from 1989 levels to 1990 levels. The chemicals were phased out completely by 1996 for CFCs and out of use by 2030 for HFCs.

CFCs were phased out by 2010 for developing nations, and HCFCs will be phased out by 2040.

Since 1987, the Protocol has undergone modifications and revisions. As of 2009, all 197 United Nations (UN) members had fully ratified the Montreal Protocol.

See the Handbook for the Montreal Protocol and this link for further details.

Countries that signed the Montreal Protocol agreed to phase out the production and consumption of ozone-depleting substances (ODS) such as chlorofluorocarbons (CFCs) and halons. They committed to implementing measures to reduce and eventually eliminate the use of these harmful chemicals, including setting specific targets and timelines for ODS reduction, implementing regulations and controls on ODS production and trade, promoting the use of alternative substances that are less harmful to the ozone layer, and cooperating with other signatory countries to monitor and enforce compliance with the protocol's provisions.