Growing allegations that the Islamic Republic of Iran may have used chemical agents against protesters have intensified scrutiny of the regime’s most recent crackdown, described by observers as the deadliest suppression of public dissent in the country’s modern history. The claims gained momentum following the circulation of footage from Sabzevar showing Iranian security forces equipped with protective gear typically associated with hazardous chemical environments, as well as testimony from protesters in Tehran describing prolonged and unusual medical symptoms after exposure to what authorities labeled “tear gas.”