Montreal Protocol on Substances that Deplete the Ozone Layer (Protocol to the Vienna Convention for the Protection of the Ozone Layer)

Subject category:
Type of agreement / instrument:
Legally-binding treaty
  • Signed by Canada September 16, 1987
  • Ratified by Canada June 30, 1988
  • In force in Canada April 1, 1989
  • In force internationally January 1, 1989
Lead & partner departments:
Environment and Climate Change Canada
Department of Foreign Affairs, Trade and Development
For further information:
Web links:
ECCC Inquiry Centre
Compendium edition:
January 2016
Reference #:

PDF; 683 KB


The objective of this agreement is to prescribe measures to equitably control and eventually eliminate the production and consumption of ozone depleting substances (ODS) in order to reduce their abundance in the atmosphere, and thereby protect the earth’s fragile ozone layer.

Key elements

The original Montreal Protocol agreement (1987) required developed country-Parties to begin phasing out chlorofluorocarbons (CFCs) in 1993 and achieve a 50% reduction relative to 1986 consumption levels by 1998. Under this agreement, CFCs and halons were the only ODS addressed.

Since 1987, the Montreal Protocol has been repeatedly strengthened by controlling additional ODS (now totalling 165), advancing the dates by which already controlled substances must be phased out, and establishing phase-out schedules for developing country-Parties. There are four amendments to the Protocol: the London Amendment (1990), the Copenhagen Amendment (1992), the Montreal Amendment (1997) and the Beijing Amendment (1999).

Parties to the Protocol meet annually and take a variety of decisions aimed at enabling effective implementation of this important legal instrument.

The Multilateral Fund (MLF) for the Implementation of the Montreal Protocol was established by a decision of the Parties and began its operation in 1991. The main objective of the Fund is to assist developing country parties to the Montreal Protocol to comply with the control measures of the Protocol.

Expected results

The primary expected result of the Montreal Protocol is the gradual reduction of the production and consumption of ozone-depleting substances, thereby reducing threats to the ozone layer.

Indicators of progress in achieving this result are:

  • Canada meets its obligations under the Montreal Protocol to prevent and minimize releases of ODS and their halocarbon alternatives and ultimately eliminate the use of ODS;
  • Canada contributes its assessed share to the Multilateral Fund for the Implementation of the Montreal Protocol;
  • Canada actively participates in all multilateral negotiations and forums to further strengthen and advance the global implementation of the Montreal Protocol;
  • Reduced consumption and production of ODS globally;
  • Targets for reduction and elimination of ODS applicable to developed and developing countries are met; and
  • Multilateral Fund projects to assist developing countries meet their targets are successfully implemented.

Canada’s involvement

Canada was one of the first countries to ratify the Montreal Protocol and is the host of the Protocol’s Multilateral Fund (MLF) Secretariat in Montreal.

The means by which this agreement is implemented in Canada is through the federal Ozone-depleting Substances Regulations, 1998 (ODSR 1998) made under CEPA.

In addition, Canada has in place a suite of federal, provincial and territorial legislation to control various aspects of the life-cycle of ODS, an Environmental Code of Practice outlining best practices for minimizing and reducing emissions for refrigeration and air conditioning equipment and Industry-led stewardship program to manage end of life refrigerants.

As a developed country, Canada also contributes to the Multilateral Fund in order to assist developing countries phase out ODS. Canada’s current annual contribution is $6.6 million.

Results / progress


In addition to hosting the Multilateral Fund Secretariat and contributing key scientific data that underpins the Montreal Protocol, Canada operates a comprehensive ozone monitoring program, which provides the international community with key information on the state of the ozone layer over the Arctic, and in hosting the World Ozone and UV Radiation Centre. The monitoring of ozone in the upper atmosphere is conducted in support of the Montreal Protocol under the Vienna Convention for the Protection of the Ozone Layer.

For the last seven years, Canada, in partnership with the U.S. and Mexico, has been actively promoting a proposal to amend the Montreal Protocol to include a phase-down of hydrofluorocarbons (HFCs) ("North American Proposal"). The aim of the amendment is to gradually reduce consumption and production of HFCs in all countries. In November 2015, Parties agreed to work towards an HFC amendment to the Montreal Protocol in 2016.


Pursuant to Article 7 of the Montreal Protocol, Canada submits annual reports to the Ozone Secretariat on the production and consumption of ODS. This information is used to ensure compliance with legal obligations under the Montreal Protocol. Data reported by Canada and other Parties can be found on the UNEP’s website.

Canada also responds to the various decisions of the Parties that regularly request that information and data on specific issues be submitted to the Secretariat.


Results from continuing global observations have confirm that atmospheric levels of key ODS are going down and it is believed that with continued, full implementation of the Protocol’s provisions the ozone layer should return to pre-1980 levels by 2050.

Controls implemented under the Montreal Protocol will enable the global community to avoid millions of cases of fatal skin cancer and tens of millions of cases of non-fatal skin cancer and eye cataracts. The Protocol has also resulted in substantial climate benefits. Because most ODS are greenhouse gases (GHGs), the Protocol has already averted GHG emissions equivalent to more than 135 billion tonnes of CO2.

Emissions reductions resulting from the phase-out of ODS contribute to protecting the environment and health of Canadians. As depletion of the ozone layer is particularly severe above the earth’s poles, Canada’s Arctic environment is particularly vulnerable to the negative effects of increased levels of UV radiation.

Domestically, ODS (CFCs and HCFCs) consumption in Canada has been reduced by almost 100%, when measured in terms of ozone-depleting potential (ODP). Globally, over 90% of ODS have been eliminated in ODP terms.

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