Chemical Weapons


Modern chemical weapons (CW) are a century old. First used on a large scale in 1915 during the First World War, they have had terrible effects on people and landscapes. They are classified as weapons of mass destruction. Luckily CW have been used very little since the end of WW1. The most well-known recent examples are the bombing of the Kurds by Saddam Hussein in 1987 (and alleged use against Iran) and the Sarin gas attack on the Tokyo subway by the Aum Shinrikyo group in 1995.

CW can have very different effects on health. They are grouped in four categories:

Blister Agents (cause severe skin, eye and mucosal pain and irritation as well as burns)

Nerve Agents (disrupt the mechanism by which nerves transfer messages to organs and may lead to death by asphyxiation as control is lost over respiratory muscles)

Choking Agents (cause a build-up of fluids in the lungs which then leads to suffocation)

Blood Agents (affect the body by being absorbed into the blood and cause death in a matter of minutes through respiratory failure)

One of the most notorious chemical weapons is none of the above four but a defoliant, designed to destroy vegetation only. Agent Orange was sprayed over large areas of Vietnam, Laos and Cambodia in the 1960s and 1970s. If contaminated with dioxin, it causes a wide variety of diseases, many of them fatal. It is an extremely toxic substance that has been linked to several forms of cancer, the birth defect spina bifida, type 2 diabetes, and disorders of the nervous, immune and endocrine systems. There may also be links to several other birth defects and reproductive disorders. In addition, land and forests previously contaminated with Agent Orange have still not recovered – after 40 years! The human toll includes US military veterans as well as thousands of Vietnamese civilians. Legal battles for compensation continue in the US courts to this day.

While not as catastrophic as nuclear weapons, any future use of chemical weapons would nevertheless cause severe environmental damage in addition to their devastating effects on humans. The effects on development would depend on many factors, including the type of weapons used, their scale of deployment in space and time, whether in a rural or urban area etc. Given that they are relatively cheap to produce and deliver, there is a real risk that – even though totally banned — they could be used in the wars of the future or by terrorists.

Destruction of stocks

Unfortunately even the destruction of CW can have serious effects on the environment, as evidenced by the bitter controversy over the destruction of thousands of nerve gas and other deadly chemical agents on the US-owned Pacific island of Johnston Atoll in the 1990s (the JACADS programme, completed November 2000). This destruction programme was in addition to the one operated at the main US depot at Tooele in Utah. Such disarmament work has to be done somewhere and investment in new destruction technologies to protect both health and the environment is an important priority.


CW are outlawed by international conventions: the 1925 Gas Protocol which bans its use and the 1993 Chemical Weapons Convention (CWC) which bans production and storage. The Organisation for the Prohibition of Chemical Weapons (OPCW) was established to implement the agreements contained in the Chemical Weapons Convention, which entered into force in 1997. It currently has 188 states parties. Among its various functions, OPCW monitors the closure of all CW production facilities and destruction of stockpiles, as well as verifying the consistency of industrial chemical declarations.

The six states that have declared possession of CW have to destroy over 8 million items, in total 70,000 metric tonnes of extremely dangerous chemicals, by April 2012. It is reported that by early 2012 more than 45% of this total had been verifiably destroyed.


Bradford University and SIPRI : Chemical and Biological Warfare Project

Federation of American Scientists

Green Cross Switzerland

Harvard Sussex Program on Chemical and Biological Armament Warfare and Arms Limitation

Henry L. Stimson Center

International Committee of the Red Cross (ICRC)

James Martin Center for Non-Proliferation Studies

Organisation for the Prohibition of Chemical Weapons (OPCW)