FDA Quietly Included Provision in GRAS Proposed Rule to Expand One ‘Loophole’ While Tightening Another
Need to Know
- FDA’s proposed rule to require mandatory GRAS notifications also has a provision to expand the Threshold of Regulation (TOR) exemption to include food additives and ingredients
- Currently, TOR only applies to food contact substances that may migrate into food, exempting qualifying substances from regulation if they are not shown to be carcinogenic and dietary concentrations remain below 0.5 parts per billion (ppb)
- The proposed expansion would allow TOR-qualifying substances directly or indirectly added to food to bypass formal FDA food additive review and GRAS notification requirements
- Unlike GRAS submissions or food additive petitions, TOR submissions only require minimal data (e.g., identity, dietary exposure); a full safety narrative is not required for a TOR submission to FDA
- Critics raised concerns that some chemicals may cause adverse health effects below 0.5 ppb even if they are not carcinogenic, and that TOR does not account for cumulative dietary exposure
- The public comment period for FDA’s proposed GRAS rule, including the TOR expansion, remains open through December 9, 2026
When the U.S. Food and Drug Administration (FDA) proposed a rule in August to tighten the Generally Recognized as Safe (GRAS) pathway—which has long been criticized as a “loophole” that allows chemicals to enter the U.S. food supply without oversight—the agency quietly added a provision to expand another pathway used to allow the use of unreviewed food contact materials to also include food additives and substances.
FDA widely publicized the August GRAS proposed rule as a win for the “Make America Healthy Again” (MAHA) movement, as it would require companies to notify the agency when they conclude that a substance used in human or animal food is GRAS. Although companies would still be able to self-determine the safety of ingredients and additives if they can provide the requisite data and evidence of their safety, the proposed rule would end the existing voluntary notification system for most GRAS substances.
What the Administration did not publicize about the proposed rule, however, are revisions to 21 CFR 170.39, also known as the Threshold of Regulation (TOR), which would open a new pathway for food additives and ingredients to enter the food supply without formal FDA review through exemption.
The public has until December 9, 2026 to submit comments on the GRAS proposed rule, including the expansion of TOR, under “Docket FDA-2025-N-3262” in the Federal Register.
What is the Threshold of Regulation Exemption?
TOR, which currently only applies to substances used in food contact materials (e.g., packaging, manufacturing/processing equipment) that may be expected to migrate into food, allows a substance to be exempt from applicable regulations if it has not been shown to be a carcinogen and its resultant dietary concentration is less than 0.5 parts per billion (ppb). Unlike GRAS submissions or food additive petitions, TOR submissions to FDA only require minimal data (e.g., identity, dietary exposure); a full safety narrative is not required for a TOR submission.
FDA’s justification for TOR is that it applies to instances where “migration is so trivial there are no concerns for safety” and “very low dietary exposure presents no meaningful safety concern.”
The August GRAS proposed rule would amend TOR to include substances used in foods as well as food contact substances.
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“We propose amending [TOR] to provide that any substance used in food (both directly or indirectly added to food) will be exempted from regulation as a food additive or from the GRAS notification requirement if it meets the TOR criteria,” FDA states in the proposed rule.
Some Substances Can Cause Harm Below TOR Threshold
According to experts who spoke to The Guardian (which was the first outlet to publish an analysis specifically highlighting the TOR exemption provision in the GRAS proposed rule), it is possible for many chemicals to cause harm—such as endocrine disruption, brain damage, and reproductive effects—at levels below 0.5 ppb, even if they are not carcinogenic. TOR expert Maricel Maffini, Ph.D., remarked, "FDA and industry have this position that 'if there’s only a little bit of something in the diet, then it’s not going to be problematic,' but that isn’t supported by science of any kind.”
Even in its current, more limited form, the TOR exemption has drawn criticism. For example, TOR enabled manufacturers to use perchlorate, more commonly known as a “rocket fuel chemical,” in grain bags, which the Environmental Defense Fund and allies said increased the amount of perchlorate detected in children’s cereals.
Other chemicals that could potentially cause harm at levels below 0.5 ppb include phthalates, bisphenols, and per- and polyfluoroalkyl substances (PFAS).
In a statement, Consumer Reports Director of Food Policy Brian Ronholm said the TOR expansion "rests on the scientifically unsupported assumption that substances present in food at dietary concentrations below 0.5 ppb—or 500 parts per trillion (ppt)—cannot pose a health risk. Current scientific data contradict this threshold, as [PFAS] such as PFOA and PFOS are known to cause adverse health effects at levels significantly lower than 500 ppt."
In an analysis for the chemicals industry (which does not take a stance "for" or "against" the proposed rule), chemicals expert and CCO of Alliance Chemical, Andre Taki, affirmed that "Some hormone-active substances are reported to have effects at very low doses, and a carcinogen screen does not test for those effects." However, he pointed out that, in the GRAS proposed rule, FDA reserves the right to refuse an exemption where “available information establishes that the proposed use may pose a public health risk."
TOR Does Not Consider Cumulative Exposure and Other Concerns
Mr. Ronholm and sources who spoke to The Guardian pointed out that TOR does not consider cumulative dietary exposure, that it creates a secondary loophole allowing carcinogens if the substance is created as an impurity, and that it provides no labeling provision enabling consumers to find out if a product contains a TOR chemical.
On cumulative exposure, Mr. Ronholm explained, "[TOR] neglects to consider that multiple direct and indirect food additives— each individually below the 500 ppt limit—could act on the same safety endpoint, potentially resulting in aggregate exposures that cause adverse health effects. Because the TOR framework operates without requiring comprehensive safety data or even ingredient identification, FDA would be virtually unable to identify these substances, rendering any evaluation of cumulative risk almost impossible."
Mr. Taki's analysis affirmed that the 0.5 ppb limit to qualify for TOR exemption is per substance, per use, which "does not account for many different substances, each present at a trace level."
Clarifying the claim that TOR allows for carcinogenic impurities, Mr. Taki explained that carcinogenic impurities are only TOR-qualifying at a lifetime cancer risk of no more than one in one million.
