The timeline of chemical weapons allegations in the Russia-Ukraine war reflects a pattern that appears closely tied to a broader pattern of disinformation and counteraccusations.  A regular cycle of mutual allegations has established itself, with Russian narratives prioritising disinformation regarding chemical incidents, and Western Powers countering with concerns relating to potential Russian cover operations. Russian allegations have been widely interpreted as an effort to pre-emptively deflect blame or justify future actions in relation to possible chemical weapon use in the conflict.

In the initial months of the conflict after Russia invaded Ukraine in February 2022, Russian forces faced unexpected resistance. Following this resistance, the first wave of CW allegations began to emerge. The early accusations were often vague, without reference to specific events and with little or no evidence presented. For example, in March 2022, Russian authorities claimed they had found evidence of US-funded biolabs in Ukraine conducting research on dangerous pathogens and including chemicals that could be weaponised. Despite the lack of credible evidence, these accusations were heavily amplified by Russian media and echoed by state officials, signalling an early attempt to create a narrative that positioned Ukraine as the aggressor. This early period saw Russia attempt to frame Ukraine as a violator of international norms, likely in an effort to justify its invasion and delegitimise Ukrainian resistance on the global stage.

As the conflict intensified, the nature of the allegations evolved. In June 2022 at the UN Security Council, Russia claimed that Ukraine was preparing a chemical false flag incident. Despite failing to provide any evidence, the accusations gained traction serving the purpose of spreading confusion and casting doubt on Ukraine’s actions whilst pre-emptively deflecting blame in the case of deliberate use of CW by Russia.

In July 2022, Russia provided another notable accusation to the OPCW involved claims that Ukraine planned a chemical provocation in Mykolaivka, Donetsk, by dispersing liquid chlorine at the Slovyansk thermal power plant. Similarly, no evidence was presented to substantiate these claims, and international observers were unable to verify the existence of such chemical threats. The timing of these allegations coincided with increased international military aid to Ukraine, suggesting a possible attempt by Russia to sway international opinion and deter further support.

From early-2023 onwards, the focus of the allegations shifted towards more specific incidents involving claims of UAVs (unmanned aerial vehicles) delivering chemical munitions. In February 2023, Russian media circulated footage purportedly showing Ukrainian drones dispersing unknown chemicals over Russian positions in Velyka Novosilka. However, the video was quickly flagged by Fenix Insight as likely staged or manipulated, given the lack of corroborating evidence and the similarity to previous disinformation tactics used in other conflicts.

Most recently, in October 2024, the Kremlin made an unfounded public statement claiming that Western-backed Ukrainian forces used toxic chemicals against Russian forces, and that Ukraine, with the support of NATO, planned to stage a chemical weapons attack.

In a significant development, the OPCW recently confirmed the presence of riot control agent CS gas in samples collected by Ukraine near confrontation lines in the Dnipropetrovsk region, following an alleged chemical incident in September 2024. CS gas is one of the most commonly used tear gases in the world. CS gas is used as a riot control agent, however, is banned for use in warfare due to the 1925 Geneva Protocol. While the use of CS gas is prohibited as a method of warfare under the Chemical Weapons Convention, the OPCW report underscores the need for independent verification mechanisms amidst the ongoing allegations from both sides.

Following the Ukrainian incursion in the Kursk region, a further spate of chemical weapons allegations have appeared, including the claim that Ukraine is clearing territory using chlorine. The evidence provided has included manipulated images which, in one case was taken in Iraq in 2015, but presented as if it relates to recent combat operations in Kursk.