According to the preliminary investigation, the letter carrier was reacting to perfume that had been sprayed on some letters.
The letter carrier, whose name was not released, is in good condition at WayneHealthCare, the captain said.
The postal service will return the truck to the postal facility in Greenville and investigate the incident further, Brandenburg said.
A U.S. Postal Service worker who fell ill while driving one of the service trucks in Greenville has triggered a possible HAZMAT incident.
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Darke County Sheriff's Chief Deputy Mark Whittaker said the postal worker, believed to be a male, was on his rounds in the 5000 block of Meeker Road when he fell ill and pulled over.
The worker ended up at WayneHealthCare, Whittaker said. His condition is not known.
Deputies have taped off the postal truck, the rectangular ones seen most often on city streets and roads, which is in a parking lot on Meeker Road.
A postal inspector called to the scene has arrived and is investigating.
Meeker Road is blocked at state Route 49 until further notice.
News Center 7 will update this developing report as more details are released.
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