Vienna Convention for the Protection of the Ozone Layer. March 22, 1985

Adopted on 22 March 1985

Preamble
The Parties to this Convention,

Conscious of the potentially harmful effects of the alteration of the ozone layer on human health and the environment

Recalling the relevant provisions of the Declaration of the United Nations Conference on the Human Environment, and in particular principle 21, which provides that «States have, in accordance with the Charter of the United Nations and the principles of international law, the sovereign right to exploit their own resources pursuant to their own environmental policies, and the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of others

Taking into account the circumstances and special needs of developing countries,

Taking into account the work and studies carried out in both international and national organizations and, in particular, the World Ozone Plan of Action of the United Nations Environment Programme,

Mindful also of the precautionary ozone layer protection measures already taken at the national and international levels

Conscious that measures to protect the ozone layer from changes resulting from human activity require international cooperation and action at the international level, and should be based on relevant scientific and technical considerations

Conscious also of the need for further research and systematic observation to acquire further scientific knowledge about the ozone layer and the possible adverse effects of its alteration

Determined to protect human health and the environment from the adverse effects of changes in the ozone layer,

Agreed on the following:

Article 1: Definitions
In this Convention:

1. «Ozone layer» means the layer of atmospheric ozone above the boundary layer of the planet.

2. «Adverse impact» means changes in the physical environment or biota, including climate change, that have significant adverse effects on human health or on the composition, regenerative capacity or productivity of natural and regulated ecosystems or materials used by humans.

3. «Alternative technologies or equipment» means technologies or equipment whose use reduces or eliminates altogether the emission of substances that have or may have an adverse effect on the ozone layer.

4. «Alternative substances» means substances that reduce, eliminate, or prevent adverse effects on the ozone layer.

5. «Parties» with capital letters means, unless otherwise indicated in the text, the Parties to this Convention.

6. «Regional Economic Integration Organization» means an organization constituted by sovereign States of a given region which is competent in the matters governed by this Convention and its Protocols and is duly authorized, in accordance with its internal procedures, to sign, ratify, accept, approve or accede to the relevant instruments.

7. «Protocols» means the Protocols of this Convention.

Article 2: General obligations
1. The Parties shall take appropriate measures, in accordance with the provisions of this Convention and those protocols in force to which they are Parties, to protect human health and the environment from adverse effects which are or may result from human activities which alter or may alter the condition of the ozone layer.

2. To this end, the Parties shall, in accordance with the means at their disposal and their capabilities:

(a) Cooperate through systematic observation, research, and exchange of information to better understand and assess the effects of human activities on the ozone layer and the effects of changes in the ozone layer on human health and the environment;

(b) Implement appropriate legislative or administrative measures and cooperate in agreeing on appropriate programme activities to control, limit, reduce or prevent human activities within their jurisdiction or control if those activities are found to have, or are likely to have, an adverse effect by altering or creating the potential for alteration of the ozone layer;

(c) Cooperate in the development of harmonized measures, procedures and standards to implement this Convention in order to adopt protocols and annexes;

(d) Cooperate with competent international bodies for the effective implementation of this Convention and the protocols to which they are parties.

3. The provisions of this Convention shall in no way affect the right of Parties to adopt, in accordance with international law, internal measures additional to those provided for in paragraphs 1 and 2 above; nor shall they affect additional internal measures already taken by Parties, provided that such measures are consistent with their obligations under this Convention.

4. The application of this article shall be based on relevant scientific and technical considerations.

Article 3: Research and systematic observation
1. The Parties undertake, as appropriate, to organize studies and scientific assessments and to co-operate, directly or through competent international bodies, on the following matters

(a) Physical and chemical processes that may affect the ozone layer;

(b) Effects on human health and other biological effects caused by changes in the state of the ozone layer, especially changes in ultraviolet solar radiation affecting living organisms (UV-B)

(d) The effects of any changes in the state of the ozone layer and any subsequent change in the intensity of UV-B radiation on natural and man-made materials used by humans;

(e) Substances, practices, processes, and activities that may affect the ozone layer and their cumulative effects;

(f) Alternative substances and technologies;

(g) Relevant social and economic issues;

and other issues discussed in detail in Appendices I and II.

2. The Parties undertake, directly or through competent international bodies, taking full account of national legislation and such activities, both national and international, to promote or carry out joint or complementary systematic observation programmes of the ozone layer and other relevant parameters as set out in annex I.

3. The Parties undertake to cooperate, directly or through competent international bodies, to ensure the collection, validation and regular, timely transmission of research data through appropriate international data centers.

Article 4: Legal and scientific and technical cooperation
1. The Parties shall promote and facilitate the exchange of scientific, technical, socio-economic, commercial and legal information relevant to this Convention in accordance with the more detailed provisions in annex II. Such information shall be made available to the bodies which the Parties agree upon. Any such body which receives information which the supplying Party considers confidential shall guarantee the non-disclosure of such information and shall compile it in such a way as to preserve its confidential nature before it is made available to all Parties.

2. The Parties shall cooperate in accordance with their national laws, regulations and practices and taking into account in particular the needs of developing countries to promote, directly or through competent international bodies, the development and transfer of technology and knowledge. Such cooperation shall be accomplished by, inter alia:

(a) Facilitating the acquisition of alternative technologies by other Parties;

(b) Providing them with information on alternative technologies and equipment and appropriate instructions or guidance;

(d) The training of the necessary scientific and technical personnel.

Article 5: Communication of information
The Parties shall forward, through the Secretariat, information on the measures they have taken to implement this Convention and the Protocols to which they are Parties, in such form and at such intervals as shall be established by the meetings of the Parties to the relevant treaty instruments.

Article 6: The Conference of the Parties
1. A Conference of the Parties is hereby established. The first meeting of the Conference of the Parties shall be convened by the Secretariat appointed on a provisional basis in accordance with Article 7, no later than one year after the entry into force of this Convention. Thereafter ordinary meetings of the Conference of the Parties shall be held at intervals to be decided by the Conference at its first meeting.

2. Extraordinary meetings of the Conference of the Parties shall be convened at such times as the Conference deems necessary or at the written request of a Party, provided that, within six months of the request being communicated to the Parties by the Secretariat, it is supported by at least one third of the Parties.

3. The Conference of the Parties shall by consensus agree upon and adopt rules of procedure and financial rules for it and any subsidiary bodies it may establish, as well as financial provisions governing the functioning of the Secretariat.

4. The Conference of the Parties shall keep under continuous review the implementation of this Convention and, in addition:

(a) Establish the form and frequency of transmission of information required under Article 5 and consider such information as well as reports submitted by any subsidiary body;

(b) Review scientific information on the state of the ozone layer, its possible alteration and the possible effects of any such alteration;

(c) Promote, in accordance with article 2, agreement on appropriate policies, strategies and measures to minimize the release of substances which cause or are likely to cause changes in the ozone layer and to make recommendations on any other measures relevant to this Convention;

(d) Adopt programs of research, systematic observation, scientific and technical cooperation, exchange of information, and transfer of technology and knowledge in accordance with Articles 3 and 4;

(e) Consider and adopt, as appropriate, amendments to this Convention or its annexes in accordance with Articles 9 and 10;

(f) Consider amendments to any protocol as well as any annexes thereto and, if so decided, recommend to the Parties to such protocols their acceptance;

(g) Consider and adopt additional annexes to this Convention in accordance with Article 10, as appropriate;

(h) Where necessary, consider and adopt protocols in accordance with Article 8;

(i) Establish such subsidiary bodies as are deemed necessary for the implementation of this Convention;

(j) Utilize, as appropriate, the services of competent international bodies and scientific committees, in particular the World Meteorological Organization and the World Health Organization, as well as the Ozone Coordination Committee, in research, systematic observation and other activities related to the objectives of this Convention, and make appropriate use of information obtained from such bodies and committees;

(k) Consider and adopt any additional measures that may be necessary to carry out the objectives of this Convention.

5. The United Nations, its specialized agencies and the International Atomic Energy Agency, as well as any State not a Party to this Convention, may be represented at meetings of the Conference of the Parties by observers. Any body or agency, whether national or international, governmental or non-governmental, qualified in fields relating to the protection of the ozone layer, that has informed the Secretariat of its wish to be represented at a meeting of the Conference of the Parties as an observer may be admitted unless at least one third of the Parties present object. The admission and participation of observers shall be subject to the rules of procedure adopted by the Conference of the Parties.

Article 7: Secretariat
1. The Secretariat shall have the following functions:

(a) The organization and servicing of meetings as provided for in Articles 6, 8, 9 and 10;

(b) To prepare and transmit reports based on information received under Articles 4 and 5 and on information received from meetings of subsidiary bodies established under Article 6;

(d) Preparing reports on its activities in carrying out its functions under this Convention and submitting them to the Conference of the Parties;

(e) To ensure the necessary coordination with other relevant international bodies and, in particular, to make such administrative and contractual arrangements as may be necessary for the effective discharge of its functions;

(f) To perform such other functions as may be determined by the Conference of the Parties.

2. The functions of the Secretariat shall be exercised provisionally by the United Nations Environment Programme until the conclusion of the first ordinary meeting of the Conference of the Parties convened pursuant to Article 6. At its first ordinary meeting, the Conference of the Parties shall establish a Secretariat from among those existing competent international organizations that have expressed willingness to serve as the Secretariat under this Convention.

Article 8: Adoption of protocols
1. The Conference of the Parties may at its meetings adopt protocols pursuant to Article 2.

The text of any proposed protocol shall be communicated to the Parties by the Secretariat at least six months before such meeting.

Article 9: Amendments to the Convention or Protocols
(1) Any Party may propose amendments to this Convention or to any protocol. Such amendments shall take due account of, inter alia, relevant scientific and technical considerations.

2. Amendments to this Convention shall be adopted at a meeting of the Conference of the Parties. Amendments to any protocol shall be adopted at a meeting of the Parties to the protocol concerned. The text of any proposed amendment to this Convention or to any protocol shall, unless the protocol otherwise provides, be communicated to the Parties by the Secretariat at least six months before the meeting at which it is proposed for adoption. The Secretariat shall also communicate the text of the proposed amendments to the signatory countries for their information.

3. The Parties shall make every effort to reach agreement on any proposed amendment to this Convention by consensus. If all means have been exhausted to reach consensus and no agreement is reached, the amendment shall as a last resort be adopted by a three-fourths majority vote of the Parties to the Convention present and voting at the meeting and submitted by the Depositary to all Parties for ratification, approval or accession.

4. The procedure referred to in paragraph 3 above shall apply to amendments to any protocol unless a two-thirds majority vote of the Parties to that protocol present and voting at the meeting is sufficient for its adoption.

5. 5. Written notifications of ratification, approval or acceptance of amendments shall be given to the Depositary. Amendments adopted in accordance with paragraph 3 or 4 above shall enter into force for those Parties having accepted them on the ninetieth day after the date of receipt by the Depositary of notification of ratification, approval or acceptance by at least three fourths of the Parties to this Convention or by at least two thirds of the Parties to this protocol, except as otherwise provided for in that protocol. Thereafter, for any other Party, the amendments shall enter into force on the ninetieth day after that Party deposits its instrument of ratification, approval or acceptance of those amendments.

6. For the purposes of this Article, the term «Parties present and voting» means Parties present and casting an affirmative or negative vote.

Article 10. Adoption and amendment of annexes
1. Annexes to this Convention or to any protocol shall form an integral part of this Convention or that protocol respectively and, unless expressly provided otherwise, a reference to this Convention or to the protocols thereto constitutes at the same time a reference to any annexes thereto. Such annexes shall be restricted to scientific, technical and administrative matters.

2. If no other provision is made for annexes to a protocol, the following procedure for the proposal, adoption and entry into force of additional annexes to this Convention or annexes to a protocol shall apply

(a) Annexes to this Convention shall be proposed and adopted in accordance with the procedure set forth in Article 9, paragraphs 2 and 3, and annexes to any protocol shall be proposed and adopted in accordance with the procedure set forth in Article 9, paragraphs 2 and 4;

(b) Any party that does not consider it possible to approve an additional annex to this Convention or an annex to any protocol to which it is a Party shall so notify the Depositary, in writing, within six months from the date of the communication of acceptance by the Depositary. The Depositary shall without delay notify all Parties of any such notification received. A Party may at any time substitute an earlier notification of objection for an acceptance, whereupon the annexes shall become effective for that Party.

(c) On the expiry of six months from the date of the communication by the Depositary, an annex shall enter into force for all those Parties to this Convention or any of the relevant Protocols which have not submitted a notification in accordance with the provisions of subparagraph (b) above.

3. The proposal, adoption and entry into force of amendments to annexes to this Convention or to any protocol shall be subject to the same procedure as that for the proposal, adoption and entry into force of annexes to the Convention or annexes to the protocols. Annexes and amendments thereto shall take due account of, inter alia, relevant scientific and technical considerations.

4. If an additional annex or an amendment to an annex is related to an amendment to this Convention or to a protocol, the additional annex or amended annex shall not enter into force until such time as the amendment to this Convention or to the protocol concerned enters into force.

Article 11. Settlement of disputes
1. In the event of a dispute between the Parties concerning the interpretation or application of this Convention, the parties concerned shall seek a solution by negotiation.

2. If the parties concerned cannot reach agreement by negotiation, they may jointly seek the good offices of, or request mediation by, a third party.

3. When ratifying, accepting, approving or acceding to this Convention, or at any time thereafter, a State or regional economic integration organization may declare in writing to the Depositary that, with respect to a dispute not resolved in accordance with paragraph 1 or paragraph 2 above, it accepts one or both of the following means of dispute settlement as compulsory

(a) Arbitration in accordance with procedures to be established by the Conference of the Parties at its first regular meeting;

(b) Submission of the dispute to the International Court of Justice.

4. If the parties have not accepted, in accordance with paragraph 3 above, either or both of the procedures, the dispute shall be submitted to conciliation in accordance with paragraph 5 below, unless the parties have agreed otherwise.

5. At the request of a party to the dispute, a conciliation commission shall be created. The commission shall be composed of an equal number of members appointed by each party concerned and a chairman chosen jointly by the members appointed by each party. The commission shall render a final decision of a recommendatory nature, which the parties shall consider in good faith.

6. The provisions of this article shall apply to any protocol unless that protocol provides otherwise.

Article 12. Signing
1. This Convention shall be open for signature by States and by regional economic integration organizations at the Federal Ministry of Foreign Affairs of the Republic of Austria in Vienna from 22 March 1985 to 21 September 1985 and at the Headquarters of the United Nations in New York from 22 September 1985 to 21 March 1986.

Article 13. Ratification, acceptance or approval
1. This Convention and any protocol shall be subject to ratification, acceptance or approval by States and by regional economic integration organizations. Instruments of ratification, acceptance or approval shall be deposited with the Depositary.

(2) Any organization referred to in paragraph 1 above which becomes a Party to the Convention or any protocol without any of its member States being a Party shall be bound by all the obligations under the Convention or protocol respectively. In the case of such an organization, one or more of its member States being a Party to a Convention or a Protocol concerned, the organization and its member States shall decide on their respective responsibilities for the performance of their obligations under the Convention or a Protocol respectively. In such cases, the organization and the member States may not exercise rights under the Convention or the relevant protocol in parallel.

3. In their instruments of ratification, acceptance or approval, the organizations referred to in paragraph 1 above shall declare the extent of their competence with respect to the matters governed by the Convention or the protocol concerned. These organizations shall also inform the Depositary of any substantial modification to the extent of their competence.

Article 14. Accession
1. This Convention and any protocol shall be open for accession by States and by regional economic integration organizations as from the date of termination of the signature of the Convention or the protocol concerned. Instruments of accession shall be deposited with the Depositary.

2. In their instruments of accession, the organizations referred to in paragraph 1 above shall declare the extent of their competence with respect to the matters governed by the Convention or the protocol concerned. These organizations shall also inform the Depositary of any substantial modification to the extent of their competence.

3. The provisions of Article 13, paragraph 2, shall apply to regional economic integration organizations that accede to this Convention or any protocol.

Article 15. Voting rights
1. Each Party to the Convention or any protocol shall have one vote.

2. Except as provided for in paragraph 1 above, regional economic integration organizations, in matters within their competence, shall exercise their right to vote with a number of votes equal to the number of their member States which are Parties to the Convention or to the protocol concerned. Such organizations shall lose their right to vote if their member States exercise theirs, and vice versa.

Article 16. Relationship between the Convention and its Protocols
1. 1. A State or a regional economic integration organization may not become a Party to a protocol unless it is, or becomes at the same time, a Party to the Convention.

2. Decisions concerning any protocol shall be made only by the parties to the protocol in question.

Article 17. Entry into force
1. This Convention shall enter into force on the ninetieth day after the date of deposit of the twentieth instrument of ratification, acceptance, approval or accession.

(2) Unless otherwise provided in that Protocol, any protocol shall enter into force on the ninetieth day after the date of deposit of the eleventh instrument of ratification, acceptance, approval or accession with respect thereto.

3. For each Party which ratifies, accepts or approves this Convention or accedes thereto after the deposit of the twentieth instrument of ratification, acceptance, approval or accession, the Convention shall enter into force on the ninetieth day after the date of deposit by such Party of its instrument of ratification, acceptance, approval or accession.

4. 4. Any protocol shall, unless such protocol otherwise provides, enter into force for a Party which ratifies, accepts, approves or accedes to it after its entry into force under paragraph 2 above, on the ninetieth day after the date of deposit by such Party of its instrument of ratification, acceptance, approval or accession or on the date on which the Convention enters into force for that Party, whichever is later.

5. For the purpose of paragraphs 1 and 2 above, any instrument deposited by a regional economic integration organization shall not be counted as additional to those deposited by member States of such organization.

Article 18. Reservations
No reservation is permitted to this Convention.

Article 19. Withdrawal
1. At any time after four years from the date on which this Convention has entered into force for a Party, that Party may withdraw from the Convention by giving written notification to the Depositary.

2. Except as provided for in a protocol, at any time after four years from the date on which such protocol has entered into force for a Party, that Party may withdraw from the protocol by giving written notification to the Depositary.

(3) Any such withdrawal shall become effective upon the expiration of one year from the date of receipt of the notice by the Depositary or such later date as may be specified in the notice of withdrawal.

4. Any Party which withdraws from this Convention shall be considered as also having withdrawn from any protocol to which it is a Party.

Article 20. Depositary
1. The Secretary-General of the United Nations shall be the Depositary of this Convention and of any protocols.

2. The Depositary shall inform the Parties in particular of:

(a) The signature of this Convention and any protocol and the deposit of instruments of ratification, acceptance or approval or accession pursuant to Articles 13 and 14;

(b) The date of entry into force of the Convention and of any protocol under article 17;

(d) Amendments to the Convention and to any protocol adopted, their acceptance by the parties thereto and the dates on which they entered into force in accordance with article 9;

(e) All communications concerning the adoption and approval of annexes and amendments thereto under article 10;

(f) Notifications by regional economic integration organizations concerning the extent of their competence with respect to matters governed by this Convention and any protocols and amendments thereto;

(g) Declarations made pursuant to Article 11, paragraph 3.

Article 21. Authentic texts
The original text of the present Convention, of which the Arabic, Chinese, English, French, Russian and Spanish versions are equally authentic, shall be deposited with the Secretary-General of the United Nations.

IN WITNESS WHEREOF the undersigned, being duly authorized thereto, have signed this Convention.

DONE at Vienna this twenty-second day of March 1985.

Annex I
Studies and systematic observations
1. The Parties to the Convention recognize that the principal scientific issues are:

(a) Changes in the ozone layer, which may result from changes in the intensity of solar ultraviolet radiation affecting living organisms (UV-B) and reaching the Earth’s surface, and possible effects on human health, organisms, ecosystems, and materials used by humans;

(b) Changes in the vertical profile of ozone that could disrupt the temperature structure of the atmosphere, and possible effects on weather and climate.

2. Parties to the Convention shall, in accordance with Article 3, cooperate in conducting research and systematic observations and in making recommendations for further research and observations in such areas as:

(a) Atmospheric physics and chemistry research

(i) Integrated theoretical modelling: further development of models that consider the interaction of radiation, dynamic and chemical processes; studies of the simultaneous effects of various man-made and natural substances on atmospheric ozone; interpretation of satellite and ground-based telemetry measurements; evaluation of the dynamics of atmospheric and geophysical parameters and development of methods to determine the causes of changes in those parameters

(ii) Laboratory measurements of change factors, absorption cross sections and interaction mechanisms of tropospheric and stratospheric chemical and photochemical processes; spectroscopic data to support field measurements in all relevant spectral bands

(iii) Field measurements: studies of concentrations and fluxes of major parent gases of both natural and anthropogenic origin; studies of atmospheric dynamics; simultaneous measurements of photochemical cognates above the Earth’s atmosphere using in situ and remote sensors; comparison of data obtained at different locations and by different instruments, including the coordination and unification of measurement nomenclature for satellite instruments; three-dimensional images of major trace atmospheric primers

(iv) Development of instruments, including satellite and non-satellite sensors for measuring trace atmospheric impurities, solar radiation fluxes and meteorological parameters;

(b) Study of the effects of changes in the ozone layer on human health, the biosphere and photodegradation processes

(i) The relationship of visible and ultraviolet solar irradiation in humans (a) to the development of both non-melanoma and melanoma skin cancers and (b) the effects on the immunological system;

(ii) Wavelength-dependent effects of UV-B radiation (a) on crops, forests and other terrestrial ecosystems and (b) on the food web of aquatic ecosystems and fisheries, as well as possible inhibition of oxygen production by marine phytoplankton

(iii) Mechanisms of UV-B radiation effects on biological substances, species and ecosystems, including the relationship between dose, dose rate and response; photoremediation, adaptation and protection

(iv) Identification of possible interactions between different wavelength zones by studying biological action spectra and spectral response to polychromatic irradiation;

(v) Effects of UV-B radiation on the sensitivity and activity of species that play an important role in the balance of the biosphere; on primary natural processes such as photosynthesis and biosynthesis

(vi) Effects of UV-B radiation on photodegradation of pollutants, agricultural chemicals, and other materials;

(i) Theoretical investigation and observation of the radiative effects of ozone and other trace elements and their effects on climatic parameters such as land and ocean surface temperatures, precipitation patterns, exchange between the troposphere and the stratosphere;

(ii) Investigation of the impact of such climate changes on various human activities;

(d) Systematic observations of:

(i) The state of the ozone layer (spatial and temporal variability in total ozone content and vertical ozone profile) through the final introduction of a global ozone observation system based on the integration of satellite and ground-based observation systems;

(ii) Tropospheric and stratospheric concentrations of parent gases for HOx, NOx and CIOx, and carbon

(iii) Temperature from the Earth’s surface to the mesosphere, using both ground-based and satellite systems

(iv) The wave composition of the solar radiation flux reaching the Earth’s atmosphere and the thermal radiation leaving it, using data from satellites;

(v) Wave composition of the solar radiation flux reaching the Earth’s surface in the ultraviolet part of the spectrum and affecting living organisms (UV-B);

(vi) The properties and distribution of aerosols from the Earth’s surface to the mesosphere, using ground-based, airborne and satellite-based observation systems

(vii) Variables of importance to climate science through high-quality meteorological surface measurement programmes;

(viii) trace elements, temperature, solar radiation flux, and aerosols, using improved global data analysis techniques.

3. The Parties to the Convention shall cooperate in promoting the appropriate scientific and technical training required to participate in the research and systematic observations specified in this annex, taking into account the special needs of developing countries. Particular attention should be given to the cross-gradation of instruments and the harmonization of observational methods to produce comparable or systematic series of scientific data.

4. The following chemicals of natural or anthropogenic origin, which are listed in no particular order, are considered to modify the chemical and physical properties of the ozone layer.

(a) Carbonaceous substances

(i) Carbon monoxide (CO). Carbon monoxide has important natural and anthropogenic sources and is believed to play a significant direct role in tropospheric photochemical processes and an indirect role in stratospheric photochemical processes.

(ii) Carbon dioxide (CO2). Carbon dioxide has important natural and anthropogenic sources and affects stratospheric ozone by affecting the thermal structure of the atmosphere.

(iii) Methane (CH4). Methane has both natural and anthropogenic sources and affects both tropospheric and stratospheric ozone.

(iv) Non-methane hydrocarbon species. Non-methane hydrocarbon species consist of a large number of chemicals, have both natural and anthropogenic sources, and play a direct role in tropospheric photochemical processes and an indirect role in stratospheric photochemical processes.

(b) Nitrogenous substances

(i) Nitrous oxide (N2O). The predominant sources of N2O are natural in nature, but their anthropogenic influence is becoming increasingly important. Nitrous oxide is a major source of stratospheric NOx, which plays a key role in regulating the amount of stratospheric ozone;

(ii) Nitrogen oxides (NOx). Terrestrial sources of NOx play an important direct role only in tropospheric photochemical processes and an indirect role in stratospheric photochemistry, with NOx input near the tropopause that can directly lead to changes in upper tropospheric and stratospheric ozone.

(i) Fully halogenated alkanes such as CCl4, CFCl3 (CFC-11), CF2Cl2 (CFC-12), C2F3Cl3 (CFC-113), C2F4Cl2 (CFC-114). Fully halocidated alkanes are anthropogenic and act as a source of ClOx, which plays a key role in ozone photochemistry, mainly at 30-50 km altitude.

(ii) Partially halocidated alkanes such as CH3Cl, CHF2Cl (CFC-22), CH3CCl3, CHFCl2 (CFC-21). The sources of CH3Cl are natural, while the other partially halogenated alkanes mentioned above are of anthropogenic origin. These gases also act as a source of stratospheric ClOx.

(d) Brominated substances

Fully halogenated alkanes such as CF3Br. These gases are anthropogenic and act as a source of BrOx, whose effects are similar to those of C1Ox.

(e) Hydrogenic substances

(i) Hydrogen (H2). Hydrogen, whose source is natural and anthropogenic, plays a minor role in stratospheric photochemistry.

(ii) Water (H2O). Water, whose source is natural, plays a very important role in both tropospheric and stratospheric photochemistry. Local sources of water vapor in the stratosphere are the oxidation of methane and, to a lesser extent, hydrogen.

Appendix II
Information exchange
1. The Parties to the Convention recognize that the collection and exchange of information is an important means of implementing the objectives of this Convention and a guarantee that any action that may be taken will be appropriate and equitable. Therefore, the Parties will exchange scientific, technical, socio-economic, business, commercial and legal information.

2. The Parties to the Convention, in deciding what information is to be collected and exchanged, shall take into account the usefulness of the information and the cost of obtaining it. The parties further recognize that the cooperation referred to in this annex should be compatible with national laws, regulations and practices with respect to patents, trade secrets and the protection of confidential and proprietary information.

3. scientific information

This includes information:

(a) On scientific research planned and conducted on a public or private basis in order to facilitate the coordination of research programs and thus the most efficient use of available national and international resources;

(b) Emission data necessary for research;

(c) Scientific results published in the specialist scientific literature on the physics and chemistry of the Earth’s atmosphere and its sensitivity to change, and particularly on the state of the ozone layer and the effects on human health, the environment and the climate of changes in the total or vertical profile of ozone on any time scale;

(d) On the evaluation of scientific results and recommendations for future research.

4. technical information.

This includes information on:

(a) The availability and cost of chemical substitutes and alternative technologies that will reduce emissions of ozone-altering substances, and related research planned or underway;

(b) The limitations and possible risks associated with the use of chemical and other substitutes and alternative technologies.

5. Socio-economic and commercial information regarding Annex I substances

This includes information on:

(a) Production and production capacity;

(b) Information on uses and trends of products

(d) The costs, risks and benefits of human activities which may indirectly cause changes in the ozone layer and the effect of control measures taken or planned for those activities.

6. Legal Information.

This includes information on:

(a) National laws, administrative measures, and legal studies relating to the protection of the ozone layer;

(b) International agreements, including bilateral agreements, relating to the protection of the ozone layer;