On 2 June 2020, the PPB deployed large amounts of tear gas in an attempt to force protestors to withdraw from the streets and squares of downtown Portland, unleashing a highly toxic cloud of airborne chemicals onto the same citizens it was tasked with protecting. That day would become known locally as ‘Tear Gas Tuesday’. Drawing on publicly available information, we counted, located and identified the different munitions used that night by the PPB, and created a simulation of the toxic tear gas cloud in order to measure the exposure, spread, and concentration of tear gas throughout the city. -FA