At least two companies have lost production because of the incidents.
General Motors briefly shut down a Flint, Mich., assembly plant last week after three production workers allegedly put baby powder in an envelope with what appeared to be Arabic writing and sent it down the assembly line on the windshield of a vehicle.
A worker at a GM plant in Wentz-ville, Mo., attempted a similar prank, but production continued. All four workers were charged with misdemeanors; GM says it will pursue criminal charges against all perpetrators.
Another potential hoax is under investigation at GM's Moraine, Ohio, plant. Tests on a powdery white substance found on a hallway trash can at GM's Warren, Mich., technical center were negative, but a few employees were given antibiotics as a precaution, a spokesman said.
Incidents at Delphi
Delphi Automotive Systems Corp. has lost production in a handful of anthrax scares and hoaxes during the past couple weeks in the United States, Mexico and Europe, spokes-man Steve Gaut said.
At a plant in Reynosa, Mexico, about 70 employees took antibiotics for nearly a week after initial tests on a substance were inconclusive. Further test results came back Tuesday, Oct. 23, showing the material was harmless. It had been put in an envelope pushed under the office door of an American manager assigned to the plant. Production was not halted in that incident.
While some reports were innocent - spotting a crushed piece of candy, for instance - Delphi is investigating the suspicious incidents and plans to fire and press criminal charges against workers found responsible for hoaxes.
"In today's heightened security environment, these kind of pranks are unwelcome and inappropriate," Gaut said. "The law enforcement and hazard materials teams in our communities are overwhelmed with these kinds of reports right now. It takes (them) away from the kinds of incidents they need to be able to respond to."
Ford Motor Co. reported a few suspicious cases, including one incident that was referred to police. Any production stoppages have been brief, and no anthrax has been detected, a Ford spokeswoman said.
Safety is the guiding force behind the handling of such incidents. Several companies have heightened security measures, providing gloves and masks to mailroom employees, for instance, officials said. At DaimlerChrysler, suspicious findings automatically result in quarantine.
Said DaimlerChrysler spokesman Trevor Hale: "Safety is a priority over production schedule."