First responders converged on Senator Collins Bangor home mid-afternoon Monday.
Earlier, Thomas Daffron, the senator's husband, opened a piece of mail.
The letter said it was poisoned with the toxin, ricin. A dose of purified ricin powder the size of a few grains of table salt can kill an adult human.
The Republican senator was in a meeting in Washington, but she soon spoke with her husband.
"I was on my way to the airport because I was supposed to take the three o'clock flight to Bangor, which of course got canceled. Which doesn't happen very often, but of all days," Collins said.
"So, I had to fly to Portland instead and drive up. And of course, I was extremely anxious and worried. So my husband sent me a picture of himself in a quarantine suit and others in hazmat suits. The dog, he, and our kitchen all had to be quarantined," she said.
According to the FBI, preliminary testing showed the substance was not a threat to the public, but before the senator learned of those the test results she was worried for family.
"I understandably was very worried about whether or not there really was ricin because I knew how dangerous it was, as it had been used in previous attacks against members of Congress," said Senator Collins.
As the debate intensified surrounding the nomination of Brett Kavanaugh to the Supreme Court, the threats against Senator Collins and her staff also increased.
"There was one night when I came home very late. I work late in Washington. And came back to my townhouse. And it was 9:30 at night. And there was a man who was waiting for me in the rain and the dark. And that was very frightening to me. He shined a flashlight into my eyes. He had a video camera and started screaming at me," Sen. Collins said.
Mainers first sent Susan Collins to Washington 22 years ago. She says today's political climate differs greatly from the late 1990s.
"It does speak to a degradation of the tone in our country and the lack of civility. And I think that's very serious. Even though it's a small number on the far left and the far right it degrades our civil discourse," said Collins.
"It makes acceptable what should be completely unacceptable," she said. "And I fear that it's going to discourage people from running for public office or serving in public office."
Senator Collins said a key to bridging the divide between ideologies is for both sides to be willing to listen without immediately rising to anger.