By Tamara Gibbons, MChem Chemistry

In 2020 António Guterres, UN Secretary-General, asserted that ‘the use of chemical weapons anywhere, by anyone, under any circumstances, is intolerable’. However, in the past decade there have been notable uses of chemical weapons (CW) by individuals, terrorists, and nation states, including in Syria, Malaysia, and Salisbury. Since 1997, the Chemical Weapons Convention (CWC) has been in force to fight against the proliferation and use of CW, but these incidents suggest that there are some shortcomings in the present legislation.

It should be stressed that in many respects, the CWC can be considered a success. 193 states have ratified the Convention, encapsulating 98% of the world’s population under its protection, and 98.9% of declared stockpiles have been destroyed.1 So, how was this otherwise effective piece of legislation circumvented for targeted assassinations and horrific mass attacks?


1. The evolution of CW and technology

The CWC was constructed in an era when the main threat faced was mass battlefield attacks. However, the use of CW has evolved, with the emergence of small-scale attacks such as the assassination attempt on Sergei Skripal in Salisbury, and the successful assassination of Kim Jong-nam in Malaysia. There has been a shift from industrial-scale facilities to surreptitious laboratory benchtops.

New compounds can be synthesised with relative ease and speed. Back-integration – the process of finding ways of making substances using non-restricted precursor chemicals – is becoming simpler. Take, for example, Novichok compounds, one of which was used in Salisbury. They were developed by the Soviet Union during the Cold War as a means of circumventing the specific chemical Schedules of the CWC, in proposition at the time.2 This research is only becoming easier as technology progresses – who knows what types of novel compound are currently stored away in a covert laboratory?

2. Non-compliance

Ultimately, recent examples of chemical weapons usage show explicit non-compliance to the CWC. Whether the perpetrator is an individual, a terrorist group, or an entire state, the CWC needs effective enforcement protocols as a form of deterrence. Presently, the Organisation for the Prohibition of Chemical Weapons (OPCW), which oversees the CWC, does not impose sanctions on violators. It only assists in gathering evidence to pass on to other parties, such as nations affected by the attack, to do the sanctioning.

So, these issues give rise to what I see as the ultimate question: how can the CWC be adapted to effectively legislate for, and enforce against, the development of new technologies?


A solution could lie in a concept termed ‘qualitative universality’: the ability of a treaty to be applicable in all scenarios, no matter what they are or how far in the future they occur.3 How can we go about implementing this?

1. Listing chemicals in the CWC

Many specific compounds are already restricted under the Schedules of the CWC – why not just add all the dangerous ones? This approach comes with many issues, including a) how to analyse the mammoth 15,000 new substances created per day,4 b) the risk of synthesis of different non-restricted and perhaps even more dangerous compounds in response, and c) accidental restriction of related compounds with legitimate uses in the medical or industrial fields. Novichok A-262 remains unlisted for some of these reasons.

2. ‘General purpose criterion’

This is a phrasing that already exists within the CWC that restricts the use of all chemical weapons, no matter the specifics. It seems simple but can be ambiguous. If a chemical has knowingly been used to harm or kill a human, it’s wrong. But where’s the limit? Do riot control agents break the CWC when used in (what could be seen as) a constructive manner? What about herbicidal warfare against another nation’s plants? All avenues of CW usage must be explored to construct the clearest general purpose criterion.

3. Ideas from other fields

Almost every scientific field has comprehensive legislation, and authors have suggested many methods to strengthen each one. These could be implemented into the CWC to increase its enforcement capability.

From suggestions made regarding the Pure Food and Drugs Act, both ex-ante and ex-post deterrence is needed – beneficial incentives to prevent non-compliance in the first place as well as clear sanctions after the fact.5 Both metaphorical carrot and stick could be used.

From the Seventh International Congress of Pesticide Chemistry, a two-step model: a series of legislative ideas presented by scientists, aware of the current developments, to politicians, who make the final decision between ideas.6

These are just two examples of how interactions between different scientific fields can aid regulation.

The topic of chemical weapons is a difficult landscape to navigate, scientifically and politically, and these ideas are only the tip of the iceberg. But I believe that careful inspection of legislative methods will bring us one step closer to eradicating chemical weapons for good.


1. Organisation for the Prohibition of Chemical Weapons. OPCW by the Numbers. [Accessed 23rd December 2021].

2. Mirzayanov V. State Secrets: An Insider’s Chronicle of the Russian Chemical Weapons Program. Denver, CO: Outskirts Press, Inc; 2008.

3. Zanders JP. The Chemical Weapons Convention and universality: A question of quality over quantity? Disarmament forum. 2002;4: 23-31

4. Hersman RKC, Claeys S, Jabbari CA. Rigid Structures, Evolving Threat – Preventing the Proliferation and Use of Chemical Weapons. Centre for Strategic and International Studies. A Report of the CSIS International Security Programme. 2019.

5. Law M. How Do Regulators Regulate? Enforcement of the Pure Food and Drugs Act, 1907-38. Journal of Law, Economics, & Organization. 2006;22(2): 459-489. [Accessed 29th November 2021].

6. Mohr H. Risk and Benefit – The Acceptance of Progress. In: Frehse H. (ed.) Pesticide Chemistry: Advances in International Research, Development and Legislation: Proceedings of the Seventh International Congress of Pesticide Chemistry (IUPAC). Hamburg: VCH Publishers; 1991. p.21-36.