Ottawa police closed Laurier Avenue between Bank And O'Connor Streets as they dealt with a suspicious package Thursday. (CBC)

A substance in a package found in the mail room at a Public Safety Canada building has been deemed non-hazardous, according to Ottawa firefighters.

Hazardous materials crews completed their testing of the powder after a floor of 269 Laurier Avenue was was evacuated as a precaution.

Ottawa fire’s hazardous materials unit was called Thursday at 9:54 a.m. after the package was discovered on the 15th floor mail room, according to firefighter spokesman Marc Messier.

Seven people who came into contact with the package — three workers, a police officer and three firefighters — were quarantined in the building after they showed possible symptoms, said Messier.

The envelope workers opened appeared to have a powder inside, said Ottawa fire district chief Michael MacCormac.

Paramedics say the three people who initially touched the package in the mailroom felt a "tingling sensation" on their hands.

They washed their hands and were no longer feeling symptoms, paramedics said. The firefighters and police officer were being held on the 15th floor as a precaution because they did not have protection when they walked in, paramedics said.

The symptoms they exhibited didn't appear to be serious, said Messier.

The remaining workers on the floor were moved to another floor, he said.

Police are now interviewing people at the scene and have taken over the investigation, said Messier.

Ottawa police closed Laurier Avenue between Bank Street and O’Connor Street for about four hours but it reopened at about 2 p.m. ET.