Executive Summary: Key Legal and Evidentiary Issues

• The Court of Appeal held that "plastic manufactured items" (PMI) qualify as a "substance" under CEPA, using ordinary statutory interpretation rules and bilingual interpretation.

• The Governor in Council's Order listing PMI as "toxic" on Schedule 1 was found reasonable because CEPA only requires a reasonable satisfaction that PMI may cause environmental harm, not proof that every plastic item is harmful.

• The Court rejected the Federal Court's insistence on quantitative laboratory testing and its focus on only "1%" of plastics entering the environment, finding these to be improper re-definitions of the problem before the decision maker.

• The Court concluded that the Order is merely enabling and does not itself invoke the criminal law power; any constitutional scrutiny properly attaches to later regulations, not to this listing step.

• The Minister's refusal to establish a Board of Review was upheld as a reasonable exercise of discretion, given the scientific consensus on macroplastic pollution and the largely policy-driven nature of the objections.

• Although the original Order technically ceased to exist after legislative amendments, the Court exercised its discretion to decide the appeal on the merits and allowed the appeal, dismissing the application for judicial review with costs, with no specific monetary amount stated in the judgment.

Factual background and regulatory context

The case arises from an Order of the Governor in Council under subsection 90(1) of the Canadian Environmental Protection Act, 1999 (CEPA 1999), listing "plastic manufactured items" (PMI) on Schedule 1 as a toxic substance. The Order was published in the Canada Gazette Part II, Volume 155 Number 10 on May 12, 2021 and was accompanied by a Regulatory Impact Analysis Statement (RIAS). The listing was part of a broader federal initiative on plastic pollution and waste. Two key documents preceded and informed the Order. First, the "Science Assessment of Plastic Pollution" reviewed over 600 peer-reviewed scientific publications and summarized the current state of the science regarding the potential impacts of plastic pollution on the environment and human health, especially macroplastics larger than 5 mm. It concluded that plastic pollution is ubiquitous in the environment and that macroplastic pollution causes or potentially causes physical harm to animals, habitats, ecosystems and plants through ingestion, suffocation, strangulation, internal hemorrhaging and disease transmission. Second, "A Proposed Integrated Management Approach to Plastic Products to Prevent Waste and Pollution" (the Discussion Paper) examined possible risk-management measures on certain PMI. It proposed that after listing PMI on Schedule 1, regulations would be developed to target specific problem items, recommending banning or restricting six single-use plastic items (checkout bags, stir sticks, six-pack rings, cutlery, straws, and foodservice ware) while recognizing that certain other single-use plastics, such as garbage bags, disposable personal care items, and drink cups and lids, were not deemed environmentally problematic. Both documents were published on October 7, 2020. These documents served different roles in the CEPA framework. The Science Assessment was meant to summarize the current state of the science regarding the potential impacts of plastic pollution on the environment and human health, as well as to inform future research and decision-making on plastic pollution in Canada. The Discussion Paper was meant to outline potential risk management measures on certain PMI and guide what should be managed and regulated following the listing of PMI as a toxic substance.

Parties, proceedings and lower court decision

In the Federal Court, several industry actors and a coalition opposed to CEPA regulation of plastics challenged both the Order listing PMI and the Minister of Environment and Climate Change's refusal to convene a Board of Review (BOR) under section 333 of CEPA. The Responsible Plastic Use Coalition (RPUC) is a not-for-profit corporation of which Dow Chemical Canada ULC, Nova Chemicals Corporation and Imperial Oil Limited are members. RPUC's mandate is to "pursue all legal remedies available to prevent the regulation of plastic manufactured items under CEPA." These parties, joined by the Attorneys General of Alberta, Saskatchewan, and British Columbia, argued that PMI were not a "substance" under CEPA, that the Order was unreasonable, that it exceeded federal constitutional competence under the criminal law power, and that the Minister had unreasonably refused a BOR despite numerous notices of objection. The Federal Court accepted much of this argument (Responsible Plastic Use Coalition v. Canada (Environment and Climate Change), 2023 FC 1511). It held that PMI in the plural did not fit the singular concept of "any manufactured item" in paragraph 3(1)(f), that the evidence did not justify listing such a broad category as toxic, that the Order was ultra vires the federal criminal law power, and that the decision not to establish a BOR was unreasonable.

Interpretation of "substance" and the CEPA scheme

On appeal, the Federal Court of Appeal undertook a fresh reasonableness review within the framework of Canada (Minister of Citizenship and Immigration) v. Vavilov, 2019 SCC 65 and Auer v. Auer, 2024 SCC 36. The Court first addressed whether PMI are a "substance" within the meaning of paragraph 3(1)(f) of CEPA. It held that they are, relying on subsection 33(2) of the Interpretation Act, R.S.C. 1985, c. I-21, which provides that words in the singular include the plural, and words in the plural include the singular, and on the French version of CEPA which speaks in the plural—"les articles manufacturés" at paragraph 3(1)(f). The Court also noted that numerous other items are listed in the plural on Schedule 1 including, for example, "plastic microbeads," "inorganic fluorides," and "inorganic arsenic compounds," indicating that plural groupings of items have long been treated as "substances" for CEPA purposes. Contextually, CEPA's broad pollution-prevention purpose and its definition of "substance" as any distinguishable kind of organic or inorganic matter supported including PMI, particularly where the RIAS defined PMI as "any items made of plastic formed into a specific physical shape or design during manufacture, and have, for their intended use, a function or functions dependent in whole or in part on their shape or design." The Court then emphasized CEPA's two-stage structure for managing toxic substances. Section 64 defines when a substance is "toxic" by reference to potential or actual harm if it "is entering or may enter the environment" in a quantity or concentration or under conditions that have or may have harmful effects. Section 90 allows the Governor in Council to add such substances to Schedule 1 upon being satisfied of their toxicity. Section 93, in turn, authorizes detailed regulations on how, where and to what extent a listed substance may be controlled, including prohibitions, limits, labelling, disposal rules and other measures. In the Court's view, the Federal Court's error was to collapse these two stages. By requiring precision in the description of individual plastic items at the listing stage, the Federal Court effectively collapsed the legislative process into a single step, rendering subsection 93(1) superfluous.

Standards of proof, scientific evidence and the "1% problem"

A central evidentiary theme was the respondents' reliance on the fact that only about 1% of plastic manufactured items produced in Canada are estimated to enter the environment each year. They argued that this low percentage and the lack of quantitative laboratory testing on specific plastic types made it unreasonable to list PMI broadly as toxic. The Court rejected this reasoning. It held that reasonableness review must focus on the decision actually made by the decision maker, not a re-framed version crafted by a reviewing court. Here, the problem was not whether 1% or 99% of PMI become pollution, but that the 1% represents 29 kilotonnes of PMI annually, cumulatively, entering the environment as plastic pollution. CEPA's section 64 expressly uses the language "may enter" and "may have" harmful effects, signaling a risk-based, precautionary standard rather than a requirement for precise dose-response thresholds. The precautionary principle under paragraph 2(1)(a) provides that where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation. On the alleged absence of proper scientific evidence, the Court considered the Science Assessment and the RIAS adequate sources for the Governor in Council to be reasonably satisfied that PMI can be toxic in the statutory sense. The Science Assessment documented widespread environmental harm, including death of aquatic life and marine mammals from plastic pollution, and concluded that macroplastic pollution causes or potentially causes physical harm to animals, habitats, ecosystems, and plants. The RIAS summarized this evidence, noted that current scientific evidence confirms that plastic pollution is ubiquitous in the environment, and explained that PMI can enter the environment as plastic pollution through a wide range of activities, including littering, environmental emergencies, wear-and-tear of certain items, or accidental release. While industry critics characterized the Science Assessment as a literature review that did not support the Order and faulted the government for not conducting traditional quantitative toxicity tests on each plastic item or polymer, the Court held that CEPA does not require a specific methodology. Section 68 gives ministers broad powers to collect and generate data and conduct investigations relating to the features or effects associated with a substance. In the context of macroplastics, the Court accepted that how harm occurs makes chemistry-centered lab testing largely irrelevant and, in some cases, unethical or impractical. Dr. Chelsea Rochman, a recognized expert on the environmental and health effects of plastic pollution, opined that the quantitative risk assessment methods used for chemicals cannot be used for macroplastics; they are neither practical nor ethical and, in any event, are unnecessary to understand the harm occurring. The Court stated that no court should require unethical testing in order to find a decision reasonable. The Court further clarified that under CEPA, "toxic" is a legal label applied to substances that cause or may cause the type of harm described in section 64; it does not require the substance to be "poisonous" in the ordinary sense. Earlier Supreme Court references to toxicity as "poisonous" in R. v. Hydro-Québec, [1997] 3 S.C.R. 213, were read as context-specific, noting that at the time CEPA, 1988 was in force and Schedule 1 at its inception comprised only nine substances, all of which were chemicals or elements.

Relationship between listing and regulation of plastics

The Court devoted substantial discussion to illustrating how CEPA's two-stage approach functions in practice, using the Single-use Plastics Prohibition Regulations, S.O.R./2022-138, as an example. PMI were first listed broadly on Schedule 1 through the Order. Subsequent regulatory work, informed by consultations, the Discussion Paper and further analysis, then singled out six specific categories of single-use plastic items for prohibitions or restrictions, with detailed definitions and targeted exceptions. The regulations define "single-use plastic foodservice ware" as PMI with plastic that "contains expanded polystyrene foam, extruded polystyrene foam, polyvinyl chloride…" This demonstrated the winnowing function of section 93, by which only particular manifestations of a toxic substance end up subject to legally enforceable controls. The Court reviewed other substances on Schedule 1 to show that broad listings followed by tailored regulations are standard practice. Substances such as asbestos, mercury and plastic microbeads are listed in general terms, while the implementing regulations then specify narrow uses, limits, exemptions or product-by-product rules. At the time PMI were listed on Schedule 1, it contained 163 substances, including non-chemical entities such as "plastic microbeads," "particulate matter," "ceramic fibre," and "wastewater effluent," as well as substances with long-term, emergent dangerous properties, such as the greenhouse gases. The Court concluded that the Order's broad listing of PMI is consistent with this history. It stressed that CEPA does not require proof that every conceivable PMI causes harm before listing; rather, it is enough that the class as a whole poses or may pose the type of environmental risks targeted by section 64, with detailed sorting left to the regulatory stage.

Constitutional analysis and division of powers

On the constitutional challenge, the Court found there is no substantive constitutional question before it as the criminal law power has not been engaged. The Order itself imposes neither a prohibition nor a sanction. There are no consequences for anyone. It simply enables further regulatory consideration under section 93. Accordingly, the criminal law power is not yet engaged in a substantive way. Any regulations adopted later to prohibit or restrict particular PMI will have to satisfy both administrative reasonableness and constitutional limits then. The Federal Court had reasoned that the Order was ultra vires the criminal law power because its breadth could, in theory, support regulations reaching PMI that are not harmful and thus "threatened the balance of federalism." The Court of Appeal rejected this approach. It held that legislation and delegated powers must be assessed based on what they do, not on what they might do. No assumption can be made that a regulatory power will be exercised unconstitutionally. The mere possibility of over-broad regulations cannot render the enabling Order unconstitutional. The Court nevertheless briefly addressed division of powers concepts. It agreed with the Federal Court that the dominant purpose of the Order is to list PMI to enable regulations to manage the environmental harm associated with plastic pollution. It reaffirmed that the environment is, by its very nature, necessarily an area of shared legislative competence, where overlap is expected. The Supreme Court in Hydro-Québec specifically noted that CEPA would not preclude the provinces from regulating and controlling pollution and that "there is a wide measure of cooperation between the federal and provincial authorities to effect common or complementary ends." The Attorney General of British Columbia argued that there are practical limitations on the ability of provinces to combat plastic pollution and that the federal government is best placed to regulate many sources of plastic pollution. With no concrete evidence that the Order was being used as a pretext to regulate matters of exclusive provincial competence, and given CEPA's clear pollution-prevention focus, the Court found no basis to invalidate the Order on federalism grounds.

The Board of Review decision and ministerial discretion

The Court also considered whether the Minister's refusal to establish a Board of Review under section 333 of CEPA was reasonable. A period of public consultation followed publication of the proposed Order and RIAS. Sixty notices of objection were filed, 52 of which included requests that the Minister establish a Board of Review. Seventeen civil society organizations, one territorial government, two local governments, and an organization representing municipalities offered support for the proposed Order; 123 industry associations or companies, two provincial governments, and one foreign government expressed opposition to the proposed Order. The statute provides that the Minister "may" establish such a board, except in a few specified situations where a board is mandatory. The Minister's task in determining whether a BOR should be established is to decide whether there is sufficient uncertainty or doubt in the underlying science. After receiving the objections, the Minister arranged for a two-stage scientific review. In response to the objections the MECC directed that the notices of objection be reviewed by scientists drawn from multiple government departments. This was followed by a second review by expert external and internal scientists with no prior involvement in the matter to ensure that the scientific process had been respected. Regarding the scientific concerns raised in the notices, scientists reviewed the 27 objections made regarding the Science Assessment's core findings on the environmental impact of macroplastic pollution to determine whether they raised sufficient uncertainty or established doubt about the evidentiary basis of the proposed Order; the scientists found that they did not. A group of independent scientists with experience in risk assessment then reviewed the 60 notices of objection to ensure the first-round review was unbiased, scientifically-sound, and considered all scientific information and arguments submitted. Based on this two-stage review, the Minister concluded that the information provided in the notices of objection did not cast doubt on the core findings of the Science Assessment. Many objections instead raised legal issues or concerns about risk management approaches, such as concerns about trade and economic harm resulting from decreased investment, reduced consumer demand, or increased costs. Others contested the breadth of the listing and argued certain classes of PMI should be exempt. The Minister determined that these were largely questions about the scope and nature of the regulatory response under section 93 rather than about whether the science showed harm from plastic pollution. The Court held that this decision was within the range of reasonable outcomes. A reasoned disagreement with a submission does not lead to the conclusion that the decision maker failed to "grapple" with the issue.

Mootness and the decision to proceed

In March 2023, the Strengthening Environmental Protection for a Healthier Canada Act, S.C. 2023, c. 12 received Royal Assent, with the result that Schedule 1 of CEPA was amended and re-introduced in two parts, and the Order in question in these proceedings no longer existed at law. The Court accepted that this created a mootness issue. It nonetheless concluded that the appeal should be decided. First, there exists an adversarial context between the parties and Schedule 1, containing identical substances, was re-introduced under the new legislation. Second, the Single-use Plastics Prohibition Regulations were enabled by the listing of PMI on CEPA's Schedule 1. Third, the time and expense invested by the parties, as well as the continued relevance of the legal issues, justify a determination on the merits. On that basis, the Court exercised its discretion to resolve the appeal despite the technical mootness.

Ruling and overall outcome

The Federal Court of Appeal ultimately allowed the Attorney General of Canada's appeal and dismissed the application for judicial review with costs in that Court and below. The constitutional question is answered in the negative. It held that the Governor in Council reasonably concluded that plastic manufactured items are a "substance" under CEPA and that PMI may cause or contribute to the type of environmental harm captured by section 64. It also found that the broad listing on Schedule 1 is compatible with both CEPA's two-stage structure and the long-standing practice of enabling wide listings followed by narrow regulations. The Court rejected the Federal Court's constitutional concerns, finding that the Order itself does not exercise the criminal law power and does not intrude on provincial jurisdiction in any proven way. It further determined that the Minister's decision not to establish a Board of Review was a reasonable application of the discretionary framework in section 333, given the demonstrated scientific consensus on macroplastic pollution and the policy-oriented nature of many objections. In the result, the appellants—the Attorney General of Canada, the Minister of the Environment and Climate Change, and the Minister of Health—were successful. Should the parties fail to agree on costs, they are to advise the Registry within 30 days of the date of the Judgment, following which the Court will give directions for the determination of costs. No specific monetary amount was stated in the judgment.