The Organization for the Prohibition of Chemical Weapons (OPCW)
and the IAEA: A Comparative Overview

Drawing upon lessons learned from the IAEA's nuclear verification system,
states have given the OPCW a strong mandate.

A. Walter Dorn and Ann Rolya

Originally published in IAEA Bulletin, 3/1993. Also available as pdf.


The long-awaited Chemical Weapons Convention (CWC)—endorsed in New York by the UN General Assembly on 30 November 1992—was opened for signature on 13 January 1993. This culminated nearly a quarter century of formal discussions and negotiations.

At the signing conference in Paris, 130 states became signatories and more have joined since then, providing a promising start to the Convention. The treaty prohibits the development, production, stockpiling, transfer, and use of chemical weapons and calls for the destruction of existing stocks. To oversee its implementation, a new international organization, the Organization for the Prohibition of Chemical Weapons (OPCW), will be established when the treaty enters into force, which could be as early as January 1995. Groundwork for the OPCW is already being done by a Preparatory Commission of signatories working in The Hague, which is to be the seat of the organization.

The OPCW will be responsible for sending inspectors to chemical plants and other sites in its Member States to verify declarations and to ensure that no prohibited activities are being performed. The IAEA—as the only existing international organization with a mandate for implementing an international verification system—is an important model for the structure and functioning of the OPCW. Many provisions in the CWC benefit from the lessons learned through the implementation of the IAEA's safeguards system in such matters as rights of access for inspectors, the designation of inspectors, and procedural arrangements.

Overall, the structure of the IAEA and that foreseen for the OPCW are quite similar. They both have a full-membership organ comprising all Member States, an executive/governing body with regional representation giving priority to those States with a more developed chemical or nuclear industry, respectively, and a Secretariat headed by a Director General and including inspectors who perform on-site verification activities. Both organizations are funded by Member States, in accordance with or guided by the United Nations' scale of assessments.

There are, nonetheless, several structural differences. Most notably, the IAEA is charged with a dual mission, that of promoting the contribution of nuclear energy to social and economic development and of seeking to ensure that nuclear materials and facilities which have been placed under safeguards are not diverted from peaceful uses. The OPCW is responsible for achieving a complete ban on chemical weapons and is not responsible, at least as currently envisaged, for the promotion of peaceful uses of chemistry and chemical sciences. In addition, the CWC requires all signatories to destroy any existing chemical weapons within 10 to 15 years. The IAEA carries out verification activities in connection with its Statute as well as a number of treaties. The OPCW is to operate only under the CWC, which has the distinctive feature of combining in a single instrument the general obligations of the States Parties to the Convention and the verification system designed to ensure compliance with those obligations.  As for verification systems, there are several similarities between the IAEA and OPCW. Each organization is responsible for ensuring the non-diversion and non-production of materials for nuclear or chemical weapons, respectively. Each agency also relies upon on-site inspections as a tool of verification, and each has authority to perform challenge or, in the IAEA's case, special inspections.

There are some main differences, however. Some arise from the different characteristics of chemical and nuclear sciences, their applications, and the structures of the industries based on them. In order to verify the complete elimination of an entire class of weapons, the OPCW inspections will cover a larger variety of activities and the inspections will be more intrusive than those of the IAEA. Provisions in the CWC for the notification and frequency of inspections are more detailed, reflecting the comprehensiveness of its verification system. The materials of concern cover a wider range: toxic chemicals and their precursors are placed in three categories which could potentially include thousands of chemicals. The IAEA covers specifically identified nuclear materials which are comparatively easier to detect and quantify.

Summaries of the structures, functions, and verification systems of the OPCW and IAEA appear in the accompanying tables. They show that many significant concepts and lessons from the IAEA have been used in developing the structure of the OPCW. No doubt, there will be many opportunities for mutually beneficial cooperation and liaison in the future. Both organizations have a major role to play in seeking to verify compliance with arms-control treaties and in helping build international order in the post-Cold War world.


The OPCW and the IAEA: Summary of structures and functions




Constitutional Document

Chemical Weapons Convention (CWC)
to enter into force 180 days after 65th State deposits instrument of ratification, but no earlier than 2 years after opening for signature (Art. XXI); earliest possible date is 13 January 1995

Statute of the IAEA
entered into force on 29 July 1957 after ratification by 18 States

Main Objectives

– Achieve object and purpose of CWC (i.e., a complete ban on chemical weapons: their development, production, stockpiling, transfer and use; and the destruction of existing chemical weapons and production facilities)

– Ensure implementation of CWC, including its verification provisions

– Provide a forum for consultation and cooperation among States Parties

– Provide assistance and protection against the use of chemical weapons (CWC, Art. VIII.1)

Promote peaceful uses of atomic energy and ensure that assistance provided is not used in such a way as to further any military purpose; administer a safeguards system designed to verify and build confidence that nuclear materials and activities covered in safeguards agreements are and remain peaceful (IAEA Statute, Art. II and III.A.5)

Location of Seat/Headquarters

The Hague, Kingdom of the Netherlands (Art. VIII.3)

Vienna, Austria


Secretary-General of the UN (Art. XXIII)

Government of the USA (Art. XXI.C)

Formal Relationship with the UN

–  To be determined

–  Relationship agreement yet to be developed


– Independent intergovernmental organization within the UN system

– Relationship agreement entered into force on 14 November 1957

Full Membership Organ

Conference of the States Parties (CSP)
composed of all parties to CWC (Art. VIII.9)

General Conference (GC)
composed of all IAEA member states (Art. V): totalling 114 (in 1992)

Main roles of full membership organ

– Consider any questions within scope of the Convention and make recommendations or take decisions on any questions raised by a State Party or brought to its attention by the Executive Council

–  Oversee and ensure compliance with the Convention

–  Elect members of the Executive Council, approve its rules of procedure and oversee its activities

–  Oversee activities of the Technical Secretariat

–  Adopt the report, programme and budget of the OPCW, submitted by the Executive Council

–  Foster international cooperation

–  Review scientific and technical developments

–  Approve at its first session any draft agreements, provisions and guidelines submitted by the Preparatory Commission

–  Appoint the Director-General of the Technical Secretariat (upon recommendation of Executive Council)

– Various financial responsibilities, including deciding on scale of financial contributions (Art. VIII.19-22)

–  Approve certain types of treaty amendments (Art. XV.5)

–  In cases of non-compliance, the CSP may restrict or suspend State Party's rights and privileges (upon recommendation of the Executive Council); recommend collective measures to States Parties and bring the issue to the attention of the UN General Assembly and Security Council (Art. XII)

– Discuss and make recommendations on any questions within scope of Statute; consider Annual Report

– Elect members of the Board

– Take decisions on matters specifically referred by the Board and propose matters for consideration by the Board

– Approve states for membership and/or suspend a member

– Approve reports to the UN and any agreements between IAEA and other organizations

– Approve appointment of the Director General

– Approve amendments to the Statute

– Various financial responsibilities, including fixing scale of assessment and approving budget of the Agency recommended by the Board (Art. V.D-F)

– In cases of non-compliance, suspend a member's privileges (upon recommendation of the Board) (Art. XIX.B)

Executive/Governing Body

Executive Council (EC)
–  41 members, designated according to geographic distribution and significance of national chemical industries, elected by the CSP for 2 year terms.

–  within each of the five geographic regions represented in the Executive Council, a designated number shall generally "be the States Parties with the most significant national chemical industry in the region as determined by internationally reported and published data" (Art. VIII.23)

Board of Governors
– 35 members, elected or designated according to geographic distribution and state of nuclear advancement; 13 are designated annually by outgoing Board and 11 are elected annually by the Conference for 2 year terms (Art. VI.A)

Main Roles of Executive/Governing Body

–  Responsible to CSP
–  Carry out powers and functions entrusted to it under the Convention, including:
- Promoting effective implementation of and compliance with CWC
– Supervising activities of Technical Secretariat
– In case of doubts/concerns regarding compliance and cases of non-compliance, consult with State Party involved and request it to take measures to redress the situation, or bring issue to attention of CSP
– May request convening of special session of CSP (Art. VIII.30-36)
– Review final inspection reports after challenge inspections (Art. IX.22) and investigations of alleged use of chemical weapons (Art. X.9)

– Carry out the functions of the Agency, subject to its responsibilities to GC (Art. VI.F)
– Prepare annual report to GC (Art. VI.J)
– Appoint Director General (Art. VII.A)
– Apportion expenses among members in accordance with scale fixed by GC (Art. XIV.D)
– Submit observations on amendments (Art. XVIII.C)
– Report non-compliance to the UN Security Council and the UN General Assembly (XII.C)
– Recommend suspension of privileges and rights of membership (Art. XIX.B)


Voting in Executive/Governing Body

– 2/3 majority on matters of substance

– Simple majority on questions of procedure (Art. VIII.29)

– 3/4 majority to cancel a challenge inspection (Art. IX.17)

– Simple majority or 2/3 majority depending on category of questions (Art. VI.E)


Technical Secretariat (TS)
– Headed by a Director-General, who is  appointed by CSP upon recommendation of Executive Council for 4 year term, renewable once (Art. VIII.43)

– Inspectorate: 150-250 inspectors (estimated)

– Headed by a Director General, who is appointed by Board with approval of General Conference for 4 year term (Art. VII.A)

– Number of staff members: 2,135 (Annual Report (AR), 1992)

– Dept. of Safeguards: approx. 200 full-time inspectors

Main Roles of the Director General

– Head and chief administrative officer of the Technical Secretariat

– Appointment of staff

– Responsible to CSP and Executive Council for functioning of Technical Secretariat

– Organization and functioning of Scientific Advisory Board

– Establishment of temporary working groups of scientific experts (Art. VIII.44-45)

– Transmit inspection reports after challenge inspections (Art. IX.22) and inform Executive Council of possible non-compliance found during other inspections (VA.II.65)

– Chief administrative officer of the Agency

– Appointment and direction of the staff

– Fulfilment of the requirements of the Board (Art. VII.A-B)

– Transmission of inspectors' Safeguards Implementation Reports (SIR) to Board (Art. XII.C)

– May determine need for a special inspection (INFCIRC/153, para.77)

Funding (Annual)

$150-250 million (estimated)

– Total: $202 million (1992 regular budget, as adjusted)

– Safeguards: $68 million

Source of Funding

From States Parties in accordance with UN scale of assessment, adjusted by CSP to take into account differences in membership between UN and OPCW (Art. VIII.7)

– From Member states in accordance with scale fixed by Conference, guided by UN scale of assessment (Art. XIV.D)

– Voluntary contributions (Art. XIV.G)




The OPCW and the IAEA: their verification systems summarized


CWC Verification System

IAEA Safeguards

Legal Foundations


Chemical Weapons Convention (esp. Art. IV-X and Verification Annex (VA))

Facility agreements (model agreements to be developed)


IAEA Statute (esp. Art. III & XII)

Non-Proliferation Treaty (esp. Art. III.1), Treaty of Tlatelolco, and Treaty of Rarotonga (Art. 2 and 4)

Safeguards Agreements and Project Agreements (modeled after INFCIRC/153 and INFCIRC/66/rev. 2)

Subsidiary Arrangements and Facility Attachments

Monitored Activities

Storage and destruction of chemical weapons (Art. IV)

Destruction or conversion of chemical weapons production facilities (Art. V)

Production, acquisition and transfer of scheduled chemicals (Art. VI)

Production of non-scheduled chemicals at other facilities (Art.VI)

Alleged use of chemical weapons investigated (Art. X)

Nuclear research

Fabrication of nuclear fuel

Fuel enrichment


Reactor operation

Waste management (Art. XII)

Materials Subject to Inspection



Scheduled chemicals: 43 toxic chemicals (or chemical families) and precursors, covering in theory thousands of chemicals, divided into three categories:

-  Schedule 1: those posing high risk to CWC (e.g., nerve agents)

-  Schedule 2: those posing significant risk (e.g., thiodiglycol)

-  Schedule 3: chemicals and precursors posing risk and generally produced in large commercial quantities (e.g., hydrogen cyanide)

Unscheduled organic chemicals, especially those containing elements phosphorus, sulfur and fluorine ("PSF-chemicals")

(Art. VI, Annex on Chemicals and VA)

Special fissionable material (enriched Uranium, Plutonium)

Source material (natural and depleted Uranium and Thorium)

Some non-nuclear materials (Art. XX and AR, 1991)










Methods of Monitoring Compliance


Data monitoring

On-site inspections:
- Initial (VA.III.1)
- Routine/systematic (Art. IV-VI)
- Challenge (Art. IX)

Examination of design information

Material accountancy

Certain operating records (Art. XII.A.3)

On-site inspections:
- Ad-hoc
- Routine
- Special (INFCIRC/153, para. 71-73)

Number of States Monitored

At least 130 (estimate based on number of original signatories at Paris signing conference, which was 130)

- 68 States with significant nuclear activity (110 States have safeguards agreements in force) (AR, 1991)

Types of Information Received

Declarations by states of their aggregate national data and plant sites (initial and annual declarations)

Declarations of transfers (Art. VI)

Other information which States may provide (Art. IX)

Declarations by States

Information derived from inspection activities

Reports by supplying States

Third party information

Other information which states may wish to provide (Art. VIII)

Types of Facilities Subject to Inspection

Chemical weapons production, storage and destruction facilities

Single small scale facilities (for Schedule 1 chemical production)

Dual-use chemical production, processing and consumption facilities (Art. III-VI)

For challenge inspections, any facility or site is in theory liable to inspection (Art. IX)

Facilities containing materials subject to safeguards such as:
- Bulk material processing facilities, including reprocessing plants
- Storage facilities
- Research reactors and critical assemblies
- Power reactors
- Conversion plants
- Fuel fabrication plants
- Enrichment plants (AR, 1992)

Number of Facilities

Approximately 1,000 for routine inspections (Schedule 1, 2 and 3 chemical facilities)

Thousands for "Other chemical production facilities" which may become subject to inspection four years after Treaty's entry into force

Unlimited number of potential sites for challenge inspections

492 nuclear facilities

321 other locations (AR, 1991)

Number of Inspections (Annual)

Over 2,000 (estimated)

2,047 (AR, 1992)

Frequency of inspection

Initial inspections: "promptly" after facility is declared (VA.III.1)

Schedule 1 facilities: Subsequent inspections to be decided by Technical Secretariat and facility agreement with State Party (VA.VI.E)

Schedule 2 facilities: Subsequent inspections to be decided by Technical Secretariat (but no more than two per calendar year per plant site) (VA.VII.B)

Schedule 3 and "other" facilities": No more than two per year per plant site; combined number for a State Party not to exceed three + 5% of total number of sites declared, or 20 inspections (whichever is lower) (VA.VIII.B and VA.IX.B)

Dependent on the nature of activities and form of nuclear material where safeguards are applied, but shall be kept to the minimum consistent with the effective implementation of safeguards (INFCIRC/66/Rev.2/III.47 and 153, para.78, 81)

Between once a year and permanent inspection

Notification of Inspections

Generally: 24 hours (VA.III.17)

Initial: 72 hours (VA.III.18)

Schedule 1: 24 hours (VA.III.17)

Schedule 2: 48 hours (VA.VII.30)

Schedule 3: 120 hours (VA.VIII.25)

Other: 120 hours (VA.IX.21)

Challenge: 12 hours (Art. IX.15)

Dependent on nature of inspections with individual States in accordance with INFCIRC/66 and 153

Ad hoc: 24-48 hours

Routine: 24 hours to 1 week, but can be also be unannounced

Special: as promptly as possible (INFCIRC/153,Para.83-84)

Decisions on Compliance

Director-General informs Executive Council of possible non-compliance (VA.II.65).

Executive Council shall consider "concerns regarding compliance and cases of non-compliance" (VIII.35)

CSP shall "review compliance" with the Convention (VIII.20)

If challenge inspection is conducted, Executive Council reviews inspection report and may "address concerns as to whether any non-compliance has occurred" (Art. IX.21-22)

Inspectors determine anomalies and inconsistencies with safeguards agreements and report any non-compliance to Director General who transmits report to Board of Governors which then calls upon State(s) to remedy any non-compliance it may have found to have occurred (Art. XII.C)


Sources and references

In preparing this overview, a number of key sources and references were used. They include:

  • "International Atomic Energy Agency Safeguards: Observations of Lessons for Verifying a CWC," by James F. Keeley, the Arms Control and Disarmament Division, Department of External Affairs, Arms Control Verification Occasional Papers, No. 1, Canada, (September 1988).
  • "Verification of a Chemical Weapons Convention: Summary of Lessons Learned from the Verification Experience of the IAEA," by Mark Mullen, Center for National Security Studies, Los Alamos National Laboratory, Briefing, Vol. 2, No. 6, United States (20 December 1991).
  • "International Atomic Energy Agency Safeguards as a Model for Verification of a Chemical Weapons Convention", by Bruno H Schiefer et. al., The Arms Control and Disarmament Division, Department of External Affairs, Arms Control Verification Occasional Papers, No.3, Canada (October 1988).
  • Selected documents and reports from the IAEA, including the Annual Report of the International Atomic Energy Agency (1991 and 1992 editions); INFCIRC/66/Rev.2, The Agency's Safeguards System; INFIRC/153, The Structure and Content of Agreements between the Agency and States Required in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons.
  • "Draft Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction." Report of the Conference on Disarmament, A/47/27 (1992).


Mr Dorn is a doctoral candidate in Chemistry at the University of Toronto and has served as the UN representative of Science for Peace since 1983. Ms Rolya is Assistant Project Coordinator for the Chemical Weapons Convention Project at Parliamentarians for Global Action.