In a statement dated February 4, the groups said eyewitness testimony, medical evaluations and independent reporting indicate that Iranian security forces deployed non-standard chemical agents during protest crackdowns.
“Victims report symptoms far exceeding ordinary tear gas exposure, including respiratory distress, neurological impairment, cardiovascular instability, persistent headaches, dizziness, and long-term systemic dysfunction,” the statement said.
The coalition said Iranian medical professionals who treated the affected individuals observed consistent clinical patterns that they described as indicative of exposure to unlawful chemical substances.
The statement did not identify the specific agents involved.
The appeal comes after an unprecedentedly violent crackdown on protests across Iran on January 8 and 9, in which thousands were killed and many more wounded.
The signatories—including Nobel Peace Prize laureate Shirin Ebadi—urged OPCW member states to invoke mechanisms under Article IX of the Chemical Weapons Convention, beginning with a formal request for clarification from Tehran.
They called for authorizing a challenge inspection and the deployment of an independent expert mission to conduct on-site inspections if Iran’s response were deemed inadequate.
The groups also urged the publication of a public factual report detailing findings and levels of cooperation, and coordinated diplomatic, legal and financial consequences including referral to United Nations bodies should Tehran deny or obstruct the process.
“Continued delay enables further harm, the destruction of evidence, and impunity,” the signatories warned, adding that any use of chemical agents against civilians would constitute “a grave violation of international law.”
Iranian authorities have previously denied using prohibited chemical substances against civilians.
The OPCW has not publicly commented on the latest claims.