The Federal Court of Canada delivered a decision on Thursday overturning the federal government’s order to list plastic-manufactured items (PMIs) under Schedule 1 of the Canadian Environmental Protection Act 1999 (CEPA). The court’s decision may affect the government’s ban on single-use plastics, which was made possible by the order.

The case was brought by the Responsible Plastic Use Coalition and several plastics manufacturing companies against the Minister of Environment and Climate Change, the Minister of Health and the Attorney General of Canada, who argued that the government did not have the authority to add PMIs to Schedule 1. According to the CEPA, several special measures to prevent pollution apply to the substances listed in Schedule 1 concerning their release and regulation.

The court also considered how the passage of Bill S-5, which amended the CEPA, would affect the legal challenge. One of the bill’s changes was to repeal and replace Schedule 1 of the CEPA with PMIs included. The amended Schedule adopts a two-tier system, where toxic substances that pose the highest risk are listed in Part 1 of the schedule and other toxic substances are listed under Part 2. PMIs are listed under Part 2 of the amended Schedule.

The court first ruled the cabinet order was unreasonable, holding that not all PMIs are toxic or have the potential to become plastic pollution, and the government, knowing that such a “broad extrapolation” would include certain PMIs that were not toxic in the listing, had acted outside its authority.

Moreover, the court found the order unconstitutional, as it had exceeded the federal government’s ability to make criminal law. The court said that, because PMIs include “items with no reasonable apprehension of environmental harm,” the bill posed a threat to the balance between federal and provincial powers because it failed to establish the required “harm to the environment” element for criminal law to be employed.

However, the court did not rule whether Bill S-5’s addition of PMIs to Schedule 1 of CEPA is constitutional. It will consider further arguments before deciding.

Steven Guilbeault, Canada’s Minister of Environment and Climate Change, said in a statement on Friday that the government was carefully reviewing the Federal Court’s decision and strongly considering an appeal. Taking a firm stance on the issue, he stated that “Canadians have been loud and clear that they want action to keep plastic out of our environment,” and promised to continue to work with provinces and territories to curb plastic waste and pollution, with next steps to be announced soon.

Alberta Premier Danielle Smith applauded the court’s decision and urged the federal government not to appeal. Notably, Alberta is home to Canada’s largest petrochemical industry and had intervened in the lawsuit, alleging the federal government’s listing of PMIs was “an unconstitutional intrusion into provincial jurisdiction” and a threat to Alberta’s economy. Following the recent court decision, Premier Smith urged the federal government to immediately remove PMIs from the list to avoid further legal action by Alberta and other provinces.