The Los Angeles County Sheriff's Department says deputies were called to the unidentified hotel on North San Vicente Boulevard shortly before 8 p.m. Thursday.
Deputy Peter Gomez says the woman who allegedly threw the powder was detained by hotel security and later released at the scene.
Gomez says Kardashian told the deputies she did not want to press charges against the woman and a non-criminal battery report was taken
Gomez says paramedics were called to the hotel, but Kardashian refused medical treatment.
He says Kardashian returned to her room, removed the powder from her hair and clothing and returned to the event.