Eric Au Yeung, 18, of San Francisco is charged with felony sale or transport of explosives and felony child endangerment, Assistant District Attorney Alex Bastian said.
Yeung and a 15-year-old male accomplice were allegedly caught selling illegal fireworks Monday in the 900 block of Grant Avenue in Chinatown, according to police.
The teenager's case will go through the juvenile justice system.
Yeung was charged by the District Attorney’s Office on Tuesday and he was in court Wednesday for arraignment; he pleaded not guilty.
He is currently in custody on $25,000 bail, according to the Sheriff’s Department.
Yeung is expected to return to court July 16, Bastian said.