A Summerville woman called Dorchester County deputies on Monday after finding a white powdery substance in an envelope addressed to her young daughter.

The letter, which was from the woman’s incarcerated son, had “anthrax” written on it, an incident report states.

The woman immediately put the envelope in her bathroom and called deputies.

Deputies, firefighters, State Law Enforcement Division officials and the Joint Terrorism Task Force responded to the woman’s home on Isabela Court in the Myers Mill subdivision, according the report.

Hazardous-materials crews tested the contents of the letter and determined that the powder wasn’t a threat.