Firefighters in Prague 4 responded to a hazardous materials discovery in a residential building on Nad Studánkou Street on Saturday, April 25, 2026, after arsenic, mercury, and radioactive thorium were found inside a home.
The substances were uncovered during a basement clean-up, including glass vials containing toxic chemicals such as cyanide and picric acid, which is historically used as an explosive.
A specialized chemical unit from Kamenice in the Central Bohemian Region was called to the scene, along with a bomb disposal expert due to the presence of picric acid.
The State Office for Nuclear Safety was also informed of the discovery of radioactive thorium.
According to Prague fire brigade spokesperson Vojtěch Rotschedl, the operation concluded around 3:45 p.m., and there was no danger to residents as the quantities were small.
The building’s inner courtyard was closed off during the operation while authorities safely removed and disposed of the dangerous substances.
Officials noted that the controlled handling of picric acid required expert intervention to prevent any risk of detonation.
The incident underscores the ongoing risks associated with undisclosed hazardous materials in older residential properties and the importance of proper disposal protocols.
