Ozone layer depletion: Montreal Protocol

Official title: 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
Global Affairs Canada
For further information:
Web links:
ECCC Inquiry Centre
Compendium edition:
February 2017
Reference #:


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. In 2016, Parties agreed to add hydrofluorocarbons (HFCs) to the control regime of the Montreal Protocol through the Kigali Amendment. HFCs do not deplete the ozone layer, but are powerful greenhouse gases (GHGs) used as alternatives to ODS phased out under the Protocol. In total, there are five amendments to the Protocol: the London Amendment (1990), the Copenhagen Amendment (1992), the Montreal Amendment (1997), the Beijing Amendment (1999), and the Kigali Amendment (2016). All these amendments are in force internationally and in Canada, except the Kigali Amendment, which will come into force at the earliest on January 1st, 2019.

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 ODS, thereby reducing threats to the ozone layer. Given that many ODS are also GHGs, a secondary expected result is a reduction of GHGs to protect the climate system. With the adoption of the Kigali Amendment, the role of the Montreal Protocol in protecting the climate has been strengthened through the addition of a phase-down of HFCs.

Indicators of progress in achieving this result are:

  • Canada meets its obligations under the Montreal Protocol to eliminate and, when applicable, reduce its consumption and production of ODS and HFCs;
  • 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 and HFCs globally;
  • Multilateral Fund projects to assist developing countries are successfully implemented and meet their phase-out targets.

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. These regulations are currently being amended to add controls on HFCs.

In addition, Canada has in place a suite of federal, provincial and territorial legislation to control various aspects of the life-cycle of ODS and HFCs, 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 to assist developing countries phase out substances controlled under the Montreal Protocol. Canada’s current annual contribution is $6.6 million. As host of the Multilateral Fund Secretariat located in Montreal, Canada also contributes to the administrative costs of this Secretariat.

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.

From 2009, Canada, in partnership with the U.S. and Mexico, promoted a proposal to amend the Montreal Protocol to include a phase-down of HFCs (i.e., the North American Proposal). The aim of the amendment was to gradually reduce consumption and production of HFCs in all countries. In October 2016, Parties agreed to amend the Protocol to incorporate a phase-down of HFCs (i.e., the Kigali Amendment).


Pursuant to Article 7 of the Montreal Protocol, Canada submits annual reports to the Ozone Secretariat on the production and consumption of ODS. These annual reports will include data on HFCs when the Kigali Amendment enters into force. 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 confirmed that atmospheric levels of key ODS are decreasing, 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 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.

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: