Tear gas, Hong Kong government’s weapon of choice, was used excessively during the 2019 Hong Kong protests to destroy civic will. It not only toxified the bodies that threaten China’s sovereignty on the streets, but also dissolved architecture's societal role as the apparatus of protection. The project puts forward a body of evidence to the UK Parliamentary inquiry into human rights violation by the Hong Kong Police Force, along with a reference and action guide that reads the flow of tear gas particles through use of force and environmental policies. By outlining the relationship between the body, built environment and the contamination of tear gas, it aims to guide the public to identify the risks and potential violations of their rights in a spatial manner. While the police continue to navigate in the lawless construct of the riot control space, the action guide addresses violations of the right to assemble and the right to non toxic environments that are inherent in the nature of tear gas. It calls for collective civil actions that can be carried out by activists and experts to collect decentralized evidence in order to document its invisible social impact for future litigation purposes.