On 25 May, a rule adopted by Maine’s Board of Environmental Protection in April 2024 came into force. Under it, manufacturers, suppliers, and distributors may not offer for sale in Maine any food packaging intended for direct food contact — bags, sleeves, bowls, plates, trays, clamshells, and similar containers made primarily from plant fibres — to which per- and polyfluoroalkyl substances, or PFAS, have been intentionally added in more than incidental amounts. The rule is an enforcement mechanism for what is, in many US markets, already the direction of travel. It is worth understanding both what it covers and why the chemistry that drove it is not going to become a minor regulatory footnote.
What PFAS were doing in packaging
The function of PFAS in food packaging is straightforward. Paper and cardboard are permeable; pizza grease, cooking oils, and liquid sauces will soak through them without treatment. PFAS are exceptionally good at preventing that. Their molecular structure repels water, oil, and grease simultaneously, which made them the default coating for fast-food wrappers, microwave popcorn bags, takeout containers, and pizza boxes from roughly the 1960s onward. The US Food and Drug Administration authorised specific PFAS uses in food contact applications for decades, on the basis that migration from packaging to food was minimal enough not to pose a safety concern.
That assessment changed. Studies conducted over roughly the last decade established that PFAS do migrate from paper packaging into food, particularly oily and hot food, and that certain compounds accumulate in the body over time. The FDA concluded that paper and paperboard packaging containing PFAS represented the primary dietary exposure pathway for PFAS from authorised food contact uses. In February 2024, it announced that the substances used as PFAS grease-proofing agents on paper and paperboard were no longer being sold by manufacturers into the US market. This was a voluntary market phase-out, not a regulatory ban; the manufacturers had committed to stop selling these substances, and the FDA had no enforcement mechanism to compel them. In January 2025, the FDA went a step further and declared the 35 food contact notifications permitting PFAS food contact substances “no longer effective,” formally removing their authorised status. Maine’s May 25 rule creates the first state-level enforcement teeth for what remains, at the federal level, a voluntary commitment without a regulatory backstop.
The bond that does not break
PFAS are a class of roughly 12,000 synthetic compounds, first manufactured at industrial scale in the 1940s. What unites them is a chain of carbon atoms bonded to fluorine atoms, and it is that bond that generates the regulatory problem. The carbon-fluorine bond is one of the strongest in organic chemistry. It is also, in the specific context of environmental chemistry, almost entirely absent from nature in the relevant forms. As Niels Damrauer, a professor of chemistry at the University of Colorado Boulder working on methods to break PFAS down, put it: there are many chemical bonds that natural systems have evolved to break, but the carbon-fluorine bonds found in PFAS are uncommon in nature and no bacteria have evolved to degrade them.
The consequence is that once PFAS enter the environment, they resist every standard degradation pathway. Sunlight does not break them. Water does not break them. Microorganisms cannot metabolise them. Depending on the specific compound and environmental conditions, estimates of their persistence range from hundreds to thousands of years. They cycle through soil and water, resist conventional water treatment, and have been detected in rainwater and snowfall at every point tested on the planet. The US Environmental Protection Agency issued its first national drinking water standards for six specific PFAS compounds in 2024; the standard for PFOA and PFOS was set at 4 parts per trillion, a figure that reflects detection thresholds and health concern rather than any practical ability to prevent the compounds from being there.
This is also why the voluntary 2024 phase-out, while significant, is not the end of the story. The PFAS from decades of food packaging use are already in the environment and are not going to degrade on any policy-relevant timescale. Stopping new additions matters; it does not retrieve what is already there.
The health picture alongside the chemistry
The environmental persistence of PFAS is the feature most frequently cited in regulatory language, but it is not the only driver of the bans. The health evidence, while still developing for many of the 12,000 compounds, has accumulated enough weight across a smaller number of well-studied PFAS to prompt significant regulatory action. The International Agency for Research on Cancer classified PFOA as a Group 1 carcinogen in 2023 — carcinogenic to humans — primarily on the basis of sufficient evidence in experimental animals and strong mechanistic evidence, with limited but significant human data for kidney and testicular cancers.
PFAS exposure has been associated with alterations in liver function, changes in immune response, cholesterol elevation, thyroid hormone disruption, developmental effects, and reduced vaccine efficacy in children. Less than one per cent of PFAS compounds have been studied for toxicity; the compound-by-compound picture remains incomplete.
The associations between PFAS exposure and health outcomes are epidemiological in nature: they are correlations observed in population studies, not controlled clinical trials. Causal mechanisms are understood for some pathways and still under investigation for others. The regulatory response has not waited for mechanistic certainty on every compound. The Madrid Statement of 2015, signed by more than 200 scientists, recommended that manufacturers find alternatives to PFAS on precautionary grounds. The decade that followed produced regulations at state, national, and international level that mostly reflect that precautionary logic applied to an accumulating body of association data.
Maine as part of a broader pattern
Maine’s May 25 food packaging rule sits within a broader state-level regulatory wave and a longer legislative programme. The state passed LD 1503 in 2021, establishing a phased plan to eliminate intentionally added PFAS across all consumer products sold in Maine by 2032. The food packaging rule is a component of that programme, not a standalone action. At least 12 US states now have enacted laws restricting PFAS in food packaging, with several more taking effect through 2026 and 2027. The European Union’s Packaging and Packaging Waste Regulation introduces its own PFAS food packaging restrictions, which take effect in August 2026.
Maine’s rule covers nine specific categories of plant-fibre food contact packaging. It applies to manufacturers with annual national sales above USD 1 billion, exempting smaller producers. It does not apply to plastic packaging, to reusable packaging, or to packaging where PFAS are present only as incidental contamination from environmental sources rather than intentional addition. The incidental contamination question is not a trivial one: PFAS from recycled paper fibre and contaminated water supplies can appear in food packaging even where no PFAS were intentionally added. Maine’s rule addresses the intentional addition specifically; the contamination route remains an open regulatory question at both state and federal level.
What to watch next
The immediate question at the federal level is whether the FDA will convert its voluntary market phase-out and its revocation of the food contact notifications into a binding rule. At present, there is no regulatory mechanism compelling compliance; a manufacturer that chose to resume selling PFAS grease-proofing substances for food packaging in the US would face no federal enforcement action.
The Biden administration EPA’s 2024 drinking water standards for PFAS have moved further into uncertainty since then. On May 18, 2026, the EPA proposed to rescind the drinking water regulations for four of the six compounds covered by the 2024 rule — PFHxS, PFNA, HFPO-DA, and PFBS — while proposing to maintain the 4 parts per trillion limits for PFOA and PFOS. The regulatory environment at the federal level is now considerably less settled than the state-level picture.
On the remediation side, researchers at the University of Colorado Boulder, the University of California Los Angeles, and several other institutions have published methods for breaking the carbon-fluorine bond using light, heat, or chemical catalysts. None has yet scaled to the point where it can address environmental PFAS contamination at any meaningful volume. The science of destroying PFAS is advancing faster than in previous years, but the scale of the contamination problem and the pace of remediation remain very far apart. For now, the regulatory strategy is stopping the flow at the source: banning the intentional use, restricting new additions, and hoping that a decades-long chemistry problem does not prove as permanent as the name “forever chemicals” implies.
