The unidentified substance found Wednesday on a Baltimore-bound Southwest flight was determined to not be a threat, a spokeswoman for the airline said.
Hazmat and rescue crews from Palm Beach County investigated a "suspicious chemical powder" found on a Southwest Airlines 737 jet, determined the powder was not dangerous and then released the plane back into the airline's control, said Ashley Dillon.
At about 7:30 p.m., the company was working to get the plane in the air and minimize the delay for passengers, she said.
The powder was found by a crew member inside a tissue box on the plane, which was headed to Baltimore-Washington Thurgood Marshall International Airport.
Emergency crews were dispatched to the tarmac and the plan was evacuated at about 4:30 p.m.
There were 137 people on the plane.
Cynthia Roldan and Julius Whigham II of The Palm Beach Post contributed to this article.
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