The small amount of powder found inside an envelope mailed to City Hall was a type of salt, the Atlanta fire department said Thursday night. Now, investigators want to know how it got there.
Investigators were called to City Hall, on Trinity Avenue, around 4:30 p.m. after an envelope containing the powder was found, according to Atlanta police spokesman Sgt. John Chafee.
“An employee opened the envelope and came in contact with a white powdery substance,” Chafee said in an emailed statement.
Firefighters and paramedics were also dispatched to City Hall. Three employees came in contact with the substance, Chafee said. All were evaluated and were in good condition, he said.
The building was not evacuated. Some streets in the area were temporarily blocked during the investigation.
Shortly before 8 p.m., investigators identified the powder as sodium azide, according to Sgt. Cortez Stafford with the fire department. The salt is a common component in vehicle airbags.
According to the Atlanta-based Centers for Disease Control and Prevention, it is a potentially deadly chemical that can quickly change into a toxic gas. In airbags, an electrical charge triggered by a crash causes sodium azide to explode and convert to nitrogen gas inside the airbag.
The investigation into the incident continued late Thursday.
