The Colorado Air Quality Control Commission has identified formaldehyde, benzene, hexavalent chromium compounds, ethylene oxide, and hydrogen sulfide as priority air toxics to address rising neighborhood air pollution levels. These toxins, known to have adverse health effects on individuals, are part of the state's initiative to create a more stringent toxic contaminants program, separate from existing EPA regulations. The new regulation 30, established as a result of Colorado House Bill 1244, targets street-level toxins and aims to enhance public health by setting health-based standards for each toxin by April 2026. The inclusion of hydrogen sulfide on the list has sparked debates, as it is not classified as a hazardous air pollutant by the EPA. Despite this, its cumulative effects and association with adverse symptoms have led to its prioritization. While industry representatives have expressed concerns about the continuous regulatory changes, advocacy groups like Green Latinos have encouraged regular reviews of the toxin list to ensure ongoing protection of residents' health. The regulation process aims to go beyond federal standards and provide the commission with flexibility in targeting specific compounds. Residents in areas like Commerce City and northeast Denver have been particularly affected by benzene emissions from sources like the Suncor refinery, leading to fines from the EPA. The selection of toxins such as hexavalent chromium and ethylene oxide was based on cancer risks and health impacts on individuals. Advocacy groups have provided data supporting the inclusion of compounds like formaldehyde and ethylene oxide, while industry associations have raised questions about the data limitations around toxins like hydrogen sulfide. Despite differing opinions, the state-led program signifies a significant step towards improving air quality and protecting public health in Colorado.