Burlington police say a letter addressed to Vermont's lone congressman was "peculiar," but not dangerous and workers are back on the job.
The discovery of the letter at mid-day Monday prompted workers to leave Welch's office while police called in a hazardous materials team to investigate.
Burlington Deputy Police Chief Andi Higbee says parts of the return address on the envelope raised concerns, but he wouldn't elaborate.
He says it's unlikely the letter will result in any criminal charges.
Welch, a Democrat, is on an overseas trip.