Massive deployment of tear gas during recent street mobilizations, particularly marked by dates such as October 17 and October 24, has sparked public health concerns across France, as thousands of women report severe menstrual and reproductive disruptions following exposure. While activist networks collect thousands of testimonies, public health authorities state that available scientific data remains insufficient to establish a direct causal link.
The widespread use of intermediate weapons during demonstrations against the high cost of living and in support of public services has brought chemical crowd-control agents under intense scrutiny. Although officially classified as non-lethal—a euphemism masking immediate effects such as ocular and skin burns, coughing, and respiratory distress, alongside nausea and vomiting—the agents trigger intense reactions. Beyond these documented acute symptoms, a growing wave of reports points toward unexpected gynecological consequences following police interventions.
Première fois de ma vie que j’ai dû taper « lacrymo allaitement » dans mon moteur de recherche en rentrant de manif. Ce n’est pas une dystopie, ce sont les recherches que ce gouvernement nous oblige à faire. Depuis le début de la mobilisation lycéenne, les gaz lacrymogènes sont… pic.twitter.com/WHEy5tiSDu
Thousands of Testimonies Prompt Calls for Independent Research
On October 8, the French collective Lacrymos de sang launched an appeal to document adverse health effects among menstruating individuals exposed to crowd-control agents. By Sunday, October 25, the collective recorded nearly 7,000 responses detailing advanced or delayed periods, intense cramps, unusual bleeding, and pregnancy losses. Manifestants in cities like Poitiers described sharp, sudden pelvic contractions and abnormal bleeding occurring outside their normal cycles following weekend clashes with the CRS place Leclerc, where some 2,500 people were caught in the gas.
Toxicology of the CS Gas and Official Government Stance
French law enforcement agencies rely on grenades, such as the CM6 and GM2L models used since the 1960s, containing 2-chlorobenzylidene malononitrile, commonly known as CS gas, a powder dispersed as an aerosol or cloud. According to Fabrizio Pariselli, toxicologist and head of the chemical risk prevention unit at CNRS, the compound activates pain receptors in the respiratory tract and eyes to force crowds to disperse. According to a 2020 dossier by molecular biologist Alexander Samuel and late CNRS research director André Picot, the chemical transformation of CS yields cyanide, which deprives interacting cells of oxygen. This oxygen deficit supposedly prompts the uterine wall to swell prematurely, leading to unexpected, heavy, and painful periods.
Precedent From International Studies and Medical Agency Positions
Scientific literature examining the long-term reproductive impacts of riot-control agents remains sparse. A 2017 review published in BMC Public Health analyzed studies between 1990 and 2015, concluding that chemical irritants can cause severe injuries and permanent disabilities. Subsequent American research following the 2020 protests examined menstrual health correlates. A 2021 study in BMC Public Health involving 1,650 participants reported that 54.5 percent experienced cycle disruptions or breast tenderness after chemical exposure, with disturbances increasing alongside the number of exposure days. A later study published in 2023 in Frontiers in Epidemiology surveyed 1,276 individuals exposed to chemical agents and found that 83 percent reported adverse reproductive effects—including 69 percent reporting uterine cramps, 55 percent reporting bleeding before expected periods, 30 percent noting breast tenderness, and 19 percent experiencing delayed periods, alongside 10 subsequent pregnancy losses out of 19 pregnant participants.
Despite these findings, French health authorities maintain that current evidence falls short of confirming causality. The Directorate-General for the Health (DGS) noted that it has not been formally seized on the matter and that potential gynecological and endocrine impacts remain insufficiently documented.
Communiqué de presse, suite à la transmission à BFM des conclusions de l’autopsie de Christophe M., décédé le 17 octobre 2026 lors de la manifestation à Paris. pic.twitter.com/thGVY6b3WY