The accidental discharge of a hazardous substance from an overhead fire extinguisher at a gas station injured 21 people in Canarsie on Saturday, the FDNY said.
Authorities responded to the hazmat situation at a BP gas station at Foster Avenue and East 80th Street.
A gray powder covered cars and people at the station.
Ten people were taken to the hospital, and 11 declined treatment, firefighters said.
It is unknown what caused the fire extinguisher to suddenly spray the material.