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UPDATE: The post office is back open for public use. Investigators say table salt was the suspicious substance that spilled from an envelope.
The fire department evacuated a Boynton Beach post office Friday morning.
The building at Congress Avenue and & Boynton Beach Boulevard was evacuated following the discovery of a suspicious powder.
The fire department says an employee noticed a white powder spill out of an envelope.
Paramedics took one person to the hospital as a precaution.
A hazardous materials team will enter the building and determine if the substance is dangerous.
One eastbound lane on Boynton Beach Boulevard has been closed.
This story will be updated when more information is available.
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