Ukraine claims that more than 12,000 cases of toxic chemical use by Russian forces have been recorded over three years of war. According to Ukrainian military sources, 6,540 such incidents were documented in 2025 alone, pointing to what Kyiv describes as a systematic pattern. Reports indicate that Russia has allegedly used chemical agents alongside conventional weapons, including K-51 and RG-VO grenades containing CS and CN tear gases. The allegations add to growing international concerns over the use of prohibited substances in modern warfare.