A hazardous chemical leak triggered mandatory evacuations across a swath of La Habra on Tuesday after a thick plume of yellow smoke began billowing from a commercial building in Orange County.
José Medrano, Mayor of the City of La Habra, addressed the unfolding emergency through a social media post, clarifying that the incident centered on the 500 block of South Cypress rather than the initial 334 S Cypress St location first reported. Los Angeles County Fire Department and Los Angeles Housing Department personnel had converged on the scene to investigate the source of the dangerous reaction, he confirmed.
“All areas east of Euclid St to Harbor Blvd and Cypress St between La Habra Blvd and Lambert Rd are blocked off evacuations are being made, please stay out of the area,” Medrano wrote in his latest update, urging the public to avoid the cordoned zone entirely.
Emergency personnel established a mandatory evacuation perimeter extending one mile in all directions from the leak site, encompassing residences and businesses alike. Hazmat crews, specially trained to handle toxic substances, joined standard first responders in the effort to contain the situation before atmospheric conditions could worsen the spread.
The reaction involved nitric and phosphoric acid, two highly corrosive chemicals that can produce severe respiratory irritation and burns upon contact. Fire crews focused their efforts on locating the compromised storage tank believed to be the leak’s origin point, working to halt the chemical reaction and prevent further contamination of surrounding neighborhoods.
Health officials issued urgent guidance for those caught in the path of the drifting plume. Anyone downwind of the site who could not evacuate immediately was instructed to seek shelter indoors, seal all windows, and shut down HVAC systems to avoid drawing toxic fumes into enclosed spaces.
The rising smoke column carried potentially toxic fumes that posed significant health risks to exposed individuals. Paramedics remained active at the scene, evaluating multiple patients for symptoms related to chemical exposure.
At least one person had sustained minor injuries by the time of the latest reports. Three additional patients were undergoing active evaluation for varying levels of physical distress connected to the incident, according to emergency updates.
The dual-acid combination involved in the leak presents particular challenges for containment specialists. Nitric acid, a powerful oxidizer, can react violently with numerous substances, while phosphoric acid adds additional corrosive hazard. Together, the pair can generate toxic nitrogen oxide gases that appear as colored smoke, matching witness descriptions of the yellow plume visible across the area.
The evacuation order covered a substantial portion of the city, with major thoroughfares including Euclid Street, Harbor Boulevard, La Habra Boulevard and Lambert Road forming the boundaries of the restricted zone. The breadth of the closure disrupted traffic and commerce across multiple blocks of the Orange County municipality.
Tuesday’s incident drew resources from multiple agencies beyond local fire departments, reflecting the scale of potential danger posed by industrial chemical storage facilities in residential-adjacent areas. The investigation into how the storage tank became compromised remained ongoing as containment efforts continued.
Fire officials had not yet provided an estimated timeline for when evacuated residents might return, pending full neutralization of the chemical threat and air quality verification throughout the affected zone.