SANTA ANA, CALIF. -- Authorities say white powder found in a tissue aboard an Alaska Airlines jetliner turned out to be a harmless substance.

Airline spokeswoman Bobbie Egan said a flight attendant found the tissue in the bathroom during a flight from Seattle to Orange County on Friday. Egan saidthe crew notified airport authorities, and an investigation was launched after the Boeing 737 landed at Orange County's John Wayne Airport.

Hazardous material investigators said the powder is harmless.

Airport spokeswoman Rachel Gibson said 151 passengers and six crew members were taken to a terminal during the investigation.