In regions like Ontario, Quebec, and the Maritimes, milk is commonly sold in plastic bags instead of the more familiar cartons or plastic jugs. While this might seem odd to visitors, the practice has been around for decades and has practical origins.
The Move Toward Plastic Packaging
Prior to 1967, milk in Canada was typically delivered in glass bottles. When DuPont developed lightweight, cost-effective plastic bags, they gained popularity quickly. Then, in 1970, Canada transitioned to the metric system. Instead of redesigning all existing glass containers to fit new measurements, bagged milk provided a flexible, convenient solution—making it a natural fit during the changeover.
