CBW Events is a project to create a record of events to enable and encourage understanding of how policies on the issues relating to chemical and biological warfare (CBW) and its prevention are developed.
CBW Events -- recent/notable additions/updates include: (these links will each open in a new window)
CBW Events -- April 2022 selections
Each month, entries for a small number of selected anniversaries of notable CBW-related events are posted. All will appear in the relevant final versions of the chronologies.
25 years ago | 30 years ago | 35 years ago | 50 years ago
25 years ago:
29 April 1997
The Chemical Weapons Convention [see 13 January 1993] enters into force with an initial 87 states parties. States that ratify or accede from now on become states parties only on the 30th day following the deposit of their instrument of ratification or accession with the UN Secretary-General. Cuba deposits its instrument of ratification for the CWC [see 28 Apr], the 88th signatory state to do so but just too late to qualify as an original state party.
30 years ago:
10 April 1992
In New York, the UN Secretary-General distributes the first six-monthly report on implementation of the plans approved under SCR 715 (1991) for the ongoing monitoring and verification of Iraq’s compliance with its obligations under Section C of SCR 687 (1991) not to use, retain, possess, develop, construct or otherwise acquire any CBW or nuclear weapons or longer-range ballistic missiles [see 18 March]. The report states that implementation has not yet begun because Iraq has not yet clearly acknowledged the obligations of SCR 715 and has accordingly failed to file the initial declarations of data required under the plan.
 The Status of the implementation of the plan for the ongoing monitoring and verification of Iraq’s compliance with relevant parts of Section C of Security Council resolution 687 (1991), Report of the Secretary-General, UN document S/23801, 10 April 1992.
35 years ago:
1 April 1987
Iraq carries out two aerial attacks against the Department of Water in Khorramshahr, killing or wounding 20 civil servants, so Iran claims in a letter to the UN Secretary-General. The letter also claims that these are in addition to other attacks that had started the previous day in which Iraq used mustard in 2 artillery shells and 40 rockets, killing or wounding 120 people. IRNA reports attacks on the cities of Abadan and Khorramshahr, and on several villages in Khuzestan province, with chemical bombs delivered from aircraft. The agency claims that anti-chemical units are deployed to neutralize the weapons. Other reporting lists the IRNA claims as relating to the "Nim Istgah-e-Navad sector in the southern warfront".
A second letter from Iran to the UN Secretary-General claims Iraq has "repeatedly resorted to chemical warfare on a very large scale on 7, 8, 9, 10 and 11 April 1987. Residential areas were the main target of these recent Iraqi chemical attacks, as a result of which in the cities of Abadan, Khorramshahr and the village of Mared at least 100 civilians were injured by chemical agents." The letter calls for "a mandatory embargo on the export to Iraq of chemical agents and the technology necessary for the production of these illegal weapons" and calls on the Secretary-General "to dispatch immediately a United Nations team to investigate the results of the most recent chemical attacks".
Iran later claims that these attacks on Khorramshahr result in a death toll of 200 with over 3000 wounded.
 Letter dated 13 April 1987 from the Permanent Representative of the Islamic Republic of Iran to the United Nations Addressed to the Secretary-General, UN document S/18799-A/42/219, 13 April 1987.
 [no author listed] (from Tehran), "Iranian Planes Raid Iraqi Positions Near Basra", Xinhua, 11 April 1987, ref 0411020; [no author listed] (from Tehran), AgenceFrance Presse, as in: "Gulf War enemies both claim successes", Independent (London), 11 April 1987, p 6.
 [No author listed] (from Nicosia), "Iran Appeals for UN Observers to Investigate Chemical Weapons Claims", Associated Press, 13 April 1987.
 Letter dated 13 April 1987 from the Permanent Representative of the Islamic Republic of Iran to the United Nations Addressed to the Secretary-General, UN document S/18800-A/42/220, 13 April 1987. See also Letter dated 28 April 1987 from the Permanent Representative of the Islamic Republic of Iran to the United Nations Addressed to the Secretary-General, UN document S/18829-A/42/257, 28 April 1987.
 Tyler Marshall (from Fish Canal, Iranian-Occupied Iraq), "Craters, barbed wire and parapets / Ferocity of Iran-Iraq War recalls trenches of WW I", Los Angeles Times, 22 April 1987, p. 1.
50 years ago:
10 April 1972
The Biological Weapons Convention is opened for signature. [see 16 November 1971]
Three signing ceremonies are held; one each in Moscow, London and Washington. States signing this day are: Afghanistan, Australia, Austria, Belgium, Benin [Dahomey], Bolivia, Botswana, Brazil, Bulgaria, Burma, Burundi, Byelorussian SSR, Canada, Central African Republic [Empire], Chile, Colombia, Costa Rica, Cyprus, Czechoslovakia, Democratic Kampuchea [Cambodia], Denmark, Dominican Republic, Egypt, El Salvador, Ethiopia, Finland, Gabon, German Democratic Republic, Germany (Federal Republic of), Ghana, Greece, Haiti, Honduras, Hungary, Iceland, Iran, Ireland, Italy, Japan, Jordan, Laos, Lebanon, Lesotho, Liberia, Luxembourg, Malawi, Mali, Mauritius, Mexico, Mongolia, Nepal, Netherlands, New Zealand, Nicaragua, Norway, Pakistan, Peru, Philippines, Poland, Republic of Korea, Romania, Rwanda, Senegal, South Africa, Spain, Sri Lanka, Switzerland, Togo, Tunisia, Turkey, Ukrainian SSR, Union of Soviet Socialist Republics, United Kingdom, United States of America, Venezuela, Yemen, Yugoslavia and Zaire.
25 April 1972
In New York, Poland, the UK and Yugoslavia, representing the three political groups in the United Nations, write to the President of the Security Council with the draft text of what is generally known as the ‘Accompanying Resolution’ to the Biological Weapons Convention [see 10 April].
The letter states: ‘we have the honour to request you to convene a meeting of the Security Council to consider the attached
draft resolution, which will be formally submitted to the Council.’
The text of the draft resolution reads:
The Security Council,
Welcoming the desire of a large number of States to subscribe to the Convention on the prohibition of the development, production and stockpiling of bacteriological (biological) and toxin weapons and on their destruction,
Determined, for the sake of all mankind, to exclude completely the possibility of bacteriological (biological) agents and toxins being used as weapons,
Bearing in mind that, under article VI of the Convention the States Parties will have the right to lodge complaints with the Security Council together with a request for their consideration by the Council,
Recognizing the desirability that appropriate measures be adopted with a view to ensuring the observance of the obligations contained in the Convention, and the particular need for urgency in the investigation of complaints where there may be a possibility that use of biological methods of warfare has been involved,
Taking into consideration that the Convention expresses the desire of the States Parties to co-operate with the Security Council for the purpose of ensuring the strict observance of the obligations contained in the Convention,
Noting further article VII of the Convention regarding the provision or support of assistance in accordance with the United Nations Charter to any Party to the Convention which so requests if the Security Council decides that such Party has been exposed to danger as a result of violation of the Convention,
l. Declares its readiness:
- to consider immediately any complaints lodged under article VI of the Convention,
- to take all necessary measures for the investigation of a complaint,
- to inform the States Parties to the Convention of the results of the investigation;
2. Calls upon all States Parties to the Convention to co-operate for the purpose of implementing the provisions of this resolution.
[Note: the Accompanying Resolution is not adopted. According to the commentary by Nicholas Sims, it was withdrawn before it came to a vote because of a threatened Chinese veto in relation to the signature of Taiwan to the BWC deposited in Washington, DC.]
 Poland, the United Kingdom and Yugoslavia, ‘Letter dated 25 April from the Permanent Representatives of Poland, the United Kingdom and Yugoslavia to the United Nations Addressed to the President of the Security Council’, S/10619, 25 April 1972, 2 pp.
 Nicholas A Sims, ‘The Evolution of Biological Disarmament’, SIPRI Chemical & Biological Warfare Studies [Scorpion Papers] no 19, Stockholm International Peace Research Institute, (2002), 200 + xi pp at p 55.