What the US FDA’s new “threshold of regulation” loophole could mean for your food
The FDA plans to widen a loophole that lets toxic chemicals enter food without safety review. Here’s what it means, who benefits, and what you can do this week.
According to The Guardian, the US Food and Drug Administration is proposing to expand a little‑used exemption – the “threshold of regulation” (TOR) – so that a range of chemicals could be added directly to food without a safety review. The move matters because it could open the door to substances that affect the endocrine system, brain development or the gut, even at levels far below the current 0.5 parts per billion (ppb) limit.
What the TOR exemption is and how it works
The TOR exemption was created for food‑contact materials – things like packaging or processing equipment – that might leach chemicals into food. If a substance is not classified as carcinogenic and is present at less than 0.5 ppb, the FDA does not require a formal safety assessment. In practice this means a company can use the chemical, keep a record, and move on.
The proposed rule would stretch the definition of “food” to include any ingredient added directly – flavourings, preservatives, emulsifiers, enzymes, stabilisers and similar ultra‑processed additives. The agency’s draft wording says any substance will be exempted from regulation "if there is no appreciable risk to human health". The phrase "appreciable risk" is not defined, leaving the safety threshold vague.
Why low‑level exposure matters
Many of the chemicals mentioned – perchlorate, certain phthalates, bisphenols, PFAS (so‑called “forever chemicals”) and flame retardants – are not carcinogenic, yet research links them to endocrine disruption, reduced thyroid hormone production and altered brain development at concentrations far below 0.5 ppb. For example, perchlorate interferes with iodine uptake in the thyroid, lowering the hormone T4 that is crucial for childhood cognitive development. Studies cited by US agencies have found that even parts‑per‑trillion exposures can reduce T4 and modestly lower IQ scores.
The evidence suggests that toxicity is not always a straight line: a tiny dose may be harmless on its own, but multiple tiny doses of different chemicals can add up, a concept known as cumulative risk. The current TOR framework does not account for this.
How the proposal differs from the existing GRAS system
The "generally recognised as safe" (GRAS) pathway, long used in the US, requires companies to provide publicly available scientific evidence that a new ingredient is safe. In practice the bar for "widely accepted" evidence can be low, and companies often host the data deep within their own websites.
The TOR expansion would bypass the GRAS safety review altogether for any substance that meets the vague "no appreciable risk" test. In effect, the TOR could become a shortcut for chemicals that would otherwise have to pass the GRAS scrutiny.
| Feature | Current TOR (food‑contact only) | Proposed TOR (direct food use) | GRAS pathway |
|---|---|---|---|
| Applies to | Packaging, processing equipment | Flavourings, preservatives, enzymes, etc. | Any new food ingredient |
| Carcinogenic check | Required | Required | Required |
| Exposure limit | < 0.5 ppb | No explicit limit, only "no appreciable risk" | No fixed limit; safety must be demonstrated |
| Review process | None (exemption) | None (exemption) | Public scientific dossier required |
| Transparency | Minimal | Minimal | Supposedly public, but often hidden |
Who stands to gain and who could lose
The most obvious beneficiary is the food industry, especially manufacturers of ultra‑processed products that rely on a cocktail of additives to achieve taste, texture and shelf‑life goals. By avoiding a formal safety review, companies can save time and money, and potentially introduce novel additives that would otherwise be blocked.
Consumers are the likely losers. The lack of a safety assessment means that any adverse health effects will only become apparent after widespread exposure, at which point mitigation is difficult. Public‑health organisations, such as the NHS, would have to deal with any increase in endocrine‑related disorders, developmental issues in children or gut‑microbiome disturbances without a clear regulatory cause.
Advocacy groups argue that the rule also benefits political actors who can claim they are "closing loopholes" while quietly widening another one. The proposal emerged alongside the FDA’s announced closure of the GRAS loophole – a move championed by high‑profile figures such as Robert F Kennedy Jr. Critics say the simultaneous TOR expansion undermines the stated goal of tighter chemical oversight.
What could go wrong or remains uncertain
- Defining "appreciable risk" – The draft rule does not set a quantitative threshold. Without a clear metric, regulators could interpret risk differently for each chemical, leading to inconsistency.
- Cumulative exposure – The current framework treats each chemical in isolation. No guidance is provided for how multiple low‑level TOR‑exempt chemicals might interact.
- Monitoring and enforcement – There is no mechanism for the FDA to test finished foods for TOR‑exempt substances once the exemption is in place. This makes post‑market surveillance almost impossible.
- International relevance – The US decision does not directly affect UK law, but multinational food companies often use the same supply chains. A change in US policy could influence ingredient choices globally, indirectly raising exposure for UK shoppers.
- Scientific gaps – For many endocrine‑disrupting chemicals, the exact dose–response curve is still debated. The evidence suggests harm at low levels, but consensus on safe limits is lacking, meaning the rule could rely on incomplete science.
What you can do this week
- Read ingredient lists carefully – Look for generic terms such as "flavouring", "stabiliser" or "enzyme" that could hide TOR‑exempt chemicals. When in doubt, check the manufacturer's website or contact them for clarification.
- Choose less‑processed options – Whole foods, minimally processed grains, fruits and vegetables are far less likely to contain hidden additives.
- Support transparency initiatives – Organisations like the Environmental Working Group and the Environmental Defence Fund maintain databases of food additives. Signing up for their newsletters or sharing their findings helps keep the issue in the public eye.
- Raise the question with your MP – Ask your local representative to request that UK regulators monitor any spill‑over effects from the US rule, especially for imports.
Taking any of these steps can reduce your personal exposure and add pressure for tighter safety standards worldwide.
