Canadian officials have acknowledged the country used Agent Orange to clear roadside brush as late as the 1980s.
Provincial Transportation Minister Kathleen Wynne promised an inquiry after the Toronto Star revealed use of the Vietnam War-era defoliant.
The chemical was used by the US military to strip Vietnam's jungles.
Vietnam says Agent Orange is responsible for massively high instances of genetic defects in areas that were sprayed.
Based on archived documents, the Toronto Star's investigation revealed that beginning in the 1950s, forestry workers were exposed to the toxic chemical as it was dumped from World War II-era planes onto birch and maple trees and shrubs.
"I don't have the specific information on how much of it was used by the ministry of transportation but the independent panel will look at that and we'll work closely with them," Ms Wynne told reporters.
Between 1962 and 1970, the US sprayed millions of gallons of Agent Orange across Vietnam in an effort to defoliate the jungle and thus deny cover to Vietcong guerrillas.
Critics say the chemical taints food and water supply, leading to crippling birth defects. In addition, the US Department of Veterans Affairs has said exposure to Agent Orange is associated with cancer and other disease.