Toxic chemicals as weapons for law enforcement

06-02-2013 Interview

In the run-up to the Chemical Weapons Convention review conference, the ICRC is urging that the use of toxic chemicals for law enforcement be limited to riot control agents – also known as ‘tear gas’ – only. Neil Davison, an ICRC expert on chemical weapons, explains.

Why is the ICRC concerned about the possible use of other toxic chemicals as weapons for law enforcement?

History provides the answer to this question. Although the use of poison as a weapon had been taboo for centuries, it was the use of poisonous gas in the First World War that finally prompted concerted international action to prohibit chemical weapons. In 1918 the ICRC summed up the public horror at the use of these weapons, calling them "barbarous inventions" that can "only be called criminal". Countries agreed an international ban of chemical (and biological) weapons in 1925 (The Geneva Protocol). This was reinforced with agreement of the 1993 Chemical Weapons Convention (and the 1972 Biological and Toxin Weapons Convention), and these treaties are bolstered by customary international law.

Despite this, there has been persistent interest among military forces and law enforcement agencies in developing and using toxic chemicals – primarily dangerous anaesthetic and sedative drugs – as weapons for law enforcement operations. These have been described as so-called "incapacitating chemical agents", "incapacitating agents" or "knock-out gas". If interest in these weapons continues, the ICRC believes it could erode the consensus against the use of poison as a weapon, and ultimately undermine international law prohibiting chemical weapons.

What are these weapons?

The primary purpose of these weapons would be to cause mass anaesthesia and unconsciousness among the people exposed by using highly potent anaesthetic and sedative chemicals to impair the functioning of the brain. They might be considered for use in various law enforcement operations. A challenge is then to provide medical treatment in an attempt to revive the people, including bystanders, who have been exposed to – and poisoned by – the chemicals.

What are the dangers for those who are exposed to these types of toxic chemicals?

This depends on the circumstances. In a medical setting, anaesthetists will use these chemicals as drugs, but very carefully in order to reduce the risk of death or serious harm. They assess the individual characteristics of the patient, looking at his or her weight, age, allergies, general health and other factors, before administering a very specific dose of the drug. Patients must be monitored continuously to ensure that they continue to breathe properly, and that their airways are not obstructed. Impairment of breathing is a common effect of anaesthetic drugs. If these same toxic chemicals are used as weapons against a group of individuals, none of these safeguards are possible. There will likely be a significant number of deaths and permanent injuries, including brain damage, among those exposed.

Are these weapons similar to ‘tear gas’?

No. ‘Tear gases’ – also known as  ‘riot control agents’ – are chemicals that cause temporary pain and irritation to eyes, skin and the respiratory tract. They have long been accepted as legitimate means for law enforcement. Their use is not without risk, but generally victims recover without the need for medical attention. There is a big difference between the amount of a riot control agent that will cause these effects and the amount that will kill.

In contrast, with powerful anaesthetic chemicals there tends to be a very small difference between the amount that will cause incapacitation and the amount that will kill. These toxic chemicals severely impair brain function, causing sedation, unconsciousness, and ultimately death. Constant individual medical attention is required for anyone exposed to such chemicals, an impractical task in a tactical situation. If used as weapons, these toxic chemicals have more in common with traditional chemical warfare agents. In fact, some chemicals that have been considered as "incapacitating" weapons for law enforcement can be as deadly as nerve agents.

Why is the ICRC commenting on the use of toxic chemicals as weapons for law enforcement?

Because – in addition to the serious threat these toxic chemicals pose to life and health, and the risk that international law prohibiting chemical weapons could be undermined – their development as weapons for law enforcement could actually lead to the use of chemical weapons in armed conflict. This ‘slippery slope’ is heightened in armed-conflict situations that are blurred, changing, and disputed. For example where law enforcement activities and the conduct of hostilities occur at the same time, or where a law enforcement situation escalates to the conduct of hostilities.

What is the ICRC calling on all States to do?

In order eliminate these risks and avoid ambiguity, the ICRC is calling on all States, if they have not already done so, to limit any use of toxic chemicals as weapons for law enforcement purposes to riot control agents only, and to enact national legislation to this effect. The ICRC is also calling on all States to promote this position at the international level with a view to strengthening the prohibition of chemical weapons. Read the full public position of the ICRC.

Why is the ICRC calling for this now?

The ICRC has raised concerns about these types of weapons for many years. However, in order to fully understand the legal, scientific and technical, operational and policy dimensions of this issue, the ICRC convened two meetings of government and independent experts in 2010 and 2012. All the main aspects of the issue were explored in detail in these settings. In September 2012 the ICRC published a synthesis of this subject as well as a short summary .

The ICRC's position is based on its own assessment of the law and the risks. It is informed by this expert meeting process as well as other meetings, workshops, and analyses. The ICRC’s call to States is aimed at preventing the serious risks posed to life, health and international law by the development and use of other toxic chemicals as weapons.


ICRC staff prepare to provide emergency health care in a simulated contaminated environment during an exercise. 

ICRC staff prepare to provide emergency health care in a simulated contaminated environment during an exercise.

A medic gives oxygen to a simulated victim of toxic chemicals during an ICRC exercise.  

A medic gives oxygen to a simulated victim of toxic chemicals during an ICRC exercise.