In the picture
A devastated landscape in Ukraine [Cesium]
In February 2026, the war in Ukraine marked four years of large-scale combat. Since the Russian invasion in 2022, substantiated allegations have indicated that Russian forces have used chemical compounds, particularly in the form of riot control agents (RCAs), against Ukrainian forces. The use of such agents as a method of warfare has been banned under the Chemical Weapons Convention (CWC), to which Russia is a state party. Russia has consistently denied Ukrainian claims regarding the use of RCAs and industrial chemicals on the battlefield; however, these claims are difficult to refute.
Riot control agents are chemical compounds that cause sensory irritation or disabling physical effects that subside shortly after exposure ends. These agents primarily affect the eyes, mouth, throat, lungs, and skin, causing symptoms such as a burning sensation, excessive coughing, shortness of breath, watery eyes, and blurred vision. Although intended to be non-lethal, exposure to high concentrations of these agents can cause severe injuries, including blindness, respiratory failure, chemical burns to the throat and lungs, or, in extreme cases, death. RCAs are composed of various chemical compounds; the most common are typically referred to as tear gas or pepper spray.
RCAs can be regarded as “dual-use” items, meaning that they can be used for peaceful (civilian and commercial) purposes, but also as weapons—or means of delivery—for military purposes. The concept of dual use creates complex ethical and security dilemmas: while both state and non-state actors could easily access such dual-use items for chemical weapons purposes, a toxic or precursor chemical could also be used, for instance, to produce pesticides that protect crops and ensure food security. Despite existing dual-use export controls, there are still numerous challenges to ensuring with certainty that dual-use items will be used for their intended peaceful purposes.
The CWC follows a General Purpose Criterion, according to which a toxic or precursor chemical is only defined as a chemical weapon if it has been developed or used for purposes prohibited by the Convention; it specifies that any chemical intended for use as a weapon is considered a chemical weapon, regardless of whether it is specifically prohibited in the Convention or its annexes. The CWC specifically bans the use of RCAs as a “method of warfare” (Art. 1.5) but permits their use for “law enforcement and domestic riot control purposes” (Art. 2.9(d)).
The primary use of chemical agents is as law enforcement tools to control crowds or restrain violent individuals. Pepper spray is also commonly used by individuals for protection and self-defense against threats. However, many have used these agents as weapons in military conflicts to destabilize opposing forces and incapacitate combatants, a practice prohibited under the CWC.
The use of RCAs in the war in Ukraine
Ukraine’s first allegation against Russia regarding the use of chemical weapons was made in September 2022, and evidence has continued to emerge since then. In May 2023, a Russian battalion commander, Vladislav Vodolazsky, claimed to have dropped grenades containing chemical agents on Ukrainian soldiers. Ukraine has requested the assistance of the OPCW to investigate Russia’s use of chemical weapons. The OPCW has released three reports—one in 2024 and two in 2025 (February and June)—on the technical assistance visit to Ukraine, which have confirmed the presence of RCAs, primarily the so-called CS gas, in grenades, as well as in soil and vegetation samples collected from the front lines.
The United States and some European countries have reached similar conclusions. In June 2024, the U.S. Embassy in Poland issued a statement announcing the imposition of sanctions against several Russian government entities and companies after determining that they had violated the CWC by using chloropicrin—a choking agent commonly used during World War I—and RCAs as methods of warfare against Ukrainian troops. Most recently, in June 2025, the Netherlands and Germany reported on the increased use of banned chemicals in Ukraine by Russian forces, calling for further sanctions against Russia and continued military support for Ukraine. Dutch and German intelligence agencies found that the use of such methods of warfare had become “standardized and commonplace” in Ukraine.
According to these findings and statements by both Ukrainian and Russian soldiers, RCAs are mainly being used to “smoke out” soldiers from trenches and other defensive positions, effectively forcing them into the line of fire where they are then attacked. The chemicals are usually contained in grenades thrown at Ukrainian fortified positions. Although soldiers receive training to counter chemical attacks, they lack adequate and sufficient protective equipment against toxic chemicals. Beyond physical effects, the use of these agents also places a psychological burden on troops, as the threat of chemical exposure creates a stressful environment that mentally destabilizes soldiers.
A complex environment in which to address the threat posed by RCAs
The availability of chemical precursors for weapons, especially those with dual-use applications, necessitates constant and sophisticated vigilance to prevent the acquisition of these products for illicit purposes. Due to globalization and the growth of international trade—despite their very positive contributions—it is becoming increasingly difficult to prevent these products from falling into the wrong hands, whether those of non-state or state actors. Consequently, the international community emphasizes the importance of states adopting harmonized monitoring and control measures to prevent the misuse of these chemicals and avoid tragic consequences. The framework for the governance of international trade in chemicals consists of various international conventions and arrangements, which provide different mechanisms and regulations that states follow to ensure the supervision of the cross-border movement of hazardous chemicals.
Export controls are one of the tools states use to restrict and prevent the trafficking of precursors for chemical weapons. This is typically carried out through the issuance of licenses by the competent authorities of the exporting state and the oversight of national authorities during customs inspections. However, national mechanisms are not designed to completely restrict trade in chemical products, as many of these products have legitimate civilian uses across various industries, such as agriculture, healthcare, manufacturing, and energy. Instead, these mechanisms are intended to prevent goods from being used for undesirable purposes, such as the production or transfer of weapons. The dual-use nature of the products necessary for the development of chemical weapons makes it difficult to identify their intended purposes, allowing them to easily evade customs controls. Although the CWC also contains regulations on the transfer and trade of chemical weapons precursors listed in its three schedules, access to these products becomes readily possible when they have other uses.
RCAs present a special case, since they are not listed in the CWC’s schedules; they are not subject to the same strict transfer restrictions as highly toxic agents, but their trade is still controlled. Under Article 3.1.e. of the CWC, states parties are required to submit an initial declaration of all chemicals held for riot control purposes. This provision is limited, as it does not require them to provide any details regarding quantity, means of delivery, or who is holding RCA stockpiles. Without such information, transparency and reporting are minimal. Nevertheless, most countries do require specific export licenses for the trade of riot control agents; for example, the EU, under Regulation 2019/125, strictly controls the export of goods that could be used for torture or other cruel treatment, including RCAs and other chemical weapons precursors.
The international legal framework regarding Russia's use of chemical weapons
Under Article VII of the CWC, all 193 States Parties are required to implement national measures to ensure that the treaty’s provisions are upheld within their jurisdictions. Similarly, United Nations Security Council (UNSC) Resolution 1540 (2004) mandates that all UN Member States adopt and enforce effective laws and measures to prevent non-State actors from acquiring, developing, or trafficking nuclear, chemical, and biological weapons, and their delivery systems. Hence, these measures are designed to translate international obligations into domestic law, targeting both government and private chemical activities. National implementation is essential, since the CWC and other measures are not self-executing, which means that they rely almost entirely on States Parties: their “success” depends to a large extent on how each State translates these regulations into its national law.
On October 23, 2025, the European Union adopted its 19th package of sanctions against Russia, which includes specific restrictions on chemicals and other dual-use goods. In light of the aforementioned allegations and evidence, the EU expanded export restrictions to include new advanced technology and dual-use items that could contribute to the Russian military-industrial complex. Some examples of such restrictions includethe prohibition on importing or transferring any acyclic hydrocarbons originating in Russia; specific chemicals used in the preparation of fuels and propellants for military systems; high-technology metals and oxides; and finished products such as rubber articles, tubes, and new tires, which contain industrial chemicals subject to strict surveillance.
Even though EU sanctions are isolating the Russian economy from the European market, and despite a perceived reduction in Russia’s revenue, the effectiveness of EU economic measures might also be undermined by Russia’s ability to find alternative suppliers in Asia and indirect transit routes via third countries. Noteworthy is the unusual increase in exports from the EU to Turkey, Kazakhstan, Armenia, and the United Arab Emirates of goods that end up in Russia. And there has been much talk about Russia’s shadow fleet, and Europe’s increasing efforts to thwart Russian attempts to circumvent sanctions.
Future prospects: the ongoing tightening of sanctions in the EU
As the war enters its fifth year, the response to Russia’s conduct in Ukraine remains politically constrained, even as evidence supporting allegations of chemical warfare and other violations continues to emerge. The OPCW’s technical assistance reports and findings have bolstered claims that the use of RCAs constitutes a violation of the CWC. Yet, EU negotiations on the proposed 20th package of sanctions against Russia were vetoed by Hungary, blocking both a €90 billion emergency loan for Kyiv and the proposed sanctions package. As of the March 2026 European Council summit, 25 of its 27 members have reaffirmed the EU’s continued support for Ukraine and their commitment to swiftly adopting the 20th sanctions package, but the deadlock has yet to be formally resolved. Holding Russia accountable requires not only a legal framework but also sustained political will, which has been difficult to maintain.