Why Did the FDA Take 35 Years to Ban Cancer-Linked Red Dye No. 3?

The US Food and Drug Administration (FDA) announced a ban on Red Dye No. 3 in foods and ingested medications on January 15, 2025, nearly 35 years after restricting the synthetic coloring in cosmetics. The decision followed longstanding evidence that high doses of the additive caused thyroid tumors in laboratory rats. Although the FDA has not established that Red No. 3 causes cancer in humans, federal law prohibits the authorization of certain color additives found to induce cancer in animals. On August 5, 2026, the agency rejected objections to the ban, confirming that manufacturers must remove the dye from foods by January 15, 2027, and ingested drugs by January 18, 2028.

What Is Red Dye No. 3?

Red Dye No. 3, officially known as FD&C Red No. 3 or erythrosine, is a synthetic color additive that produces a bright cherry-red or pink appearance in food and pharmaceutical products.

It has historically been used in candy, cookies, cakes, frostings, frozen desserts, dietary supplements and some oral medications.

The additive is also identified internationally as E127. Its primary purpose is to enhance a product's appearance rather than provide nutritional or preservative benefits.

Red No. 3 was first authorized for certain uses in the United States in 1907 and received permanent FDA authorization for food and ingested drugs in 1969.

Why Did the FDA Ban Red Dye No. 3?

The FDA revoked authorization for Red No. 3 after reviewing evidence that high dietary exposure caused thyroid tumors in male laboratory rats.

The findings involved a hormonal mechanism affecting the thyroid. According to the FDA, this particular cancer-causing mechanism in rats does not occur in humans.

The agency also noted that typical human exposure levels are much lower than those associated with tumors in the animal studies.

However, the decision was governed by the Delaney Clause, a provision of federal law that prohibits the authorization of color additives found to induce cancer in humans or animals.

As a result, the FDA was required to revoke Red No. 3's authorization even though the available scientific evidence did not establish that its permitted use caused cancer in humans.

Why Did the FDA Take More Than Three Decades to Act?

The lengthy regulatory process reflected differences between existing product authorizations, scientific assessments of cancer risk and the legal procedures required to remove a previously approved additive.

The 1990 Cosmetics Restriction Did Not Cover Food

In February 1990, the FDA terminated the provisional authorization for Red No. 3 in cosmetics and externally applied medications after reviewing animal studies showing thyroid tumors.

However, the agency did not simultaneously revoke the dye's permanent authorization for food and ingested drugs, which had been established in 1969.

The distinction allowed manufacturers to continue using Red No. 3 in certain consumable products despite restrictions on its use in cosmetics.

Regulators Considered the Human Cancer Risk Unproven

FDA scientists concluded that the mechanism responsible for thyroid tumors in male rats was not relevant to humans in the same way.

Other animal studies and available human evidence had not demonstrated comparable effects.

This scientific interpretation contributed to the distinction between the demonstrated animal hazard and the agency's assessment of potential human health risks.

Nevertheless, the statutory prohibition did not depend solely on whether ordinary human dietary exposure was likely to cause cancer.

The Existing Food Authorization Remained in Place

After the cosmetics restriction, the FDA indicated that it would consider further action concerning Red No. 3 in food.

However, the permanent food authorization remained in effect for decades, drawing criticism from consumer advocacy organizations.

These groups argued that the agency's continued authorization of the dye was inconsistent with the legal standard applied to cancer-causing color additives.

A 2022 Petition Led to the Final Decision

In October 2022, the Center for Science in the Public Interest and other petitioners formally requested that the FDA revoke Red No. 3's authorization for food and ingested drugs.

The petition cited the existing animal cancer findings and argued that the Delaney Clause required regulatory action.

Following its review, the FDA issued the revocation order on January 15, 2025. The decision was published in the Federal Register the following day.

What Is the Delaney Clause?

The Delaney Clause is a provision of the Federal Food, Drug, and Cosmetic Act that restricts the authorization of certain additives found to cause cancer in humans or animals.

The relevant color additive prohibition was enacted through the Color Additives Amendment of 1960.

Unlike a conventional risk assessment, which evaluates potential harm at expected exposure levels, the Delaney Clause establishes a legal restriction based on evidence of cancer induction.

For Red No. 3, the FDA determined that the findings of thyroid tumors in male rats met this statutory standard.

The agency therefore concluded that it could no longer maintain the dye's authorization for food or ingested medications.

Does Red Dye No. 3 Cause Cancer in Humans?

There is no established scientific evidence that Red No. 3 causes cancer in humans at typical dietary exposure levels.

The laboratory findings underlying the prohibition involved thyroid tumors in male rats exposed to high concentrations of the coloring.

The FDA has explained that the hormonal mechanism associated with those tumors differs from the relevant biological processes in humans.

Studies involving humans and other animal species have not demonstrated the same cancer effects.

However, the absence of demonstrated human cancer risk does not override the legal requirement that applies to color additives shown to induce cancer in laboratory animals.

The prohibition is therefore best understood as a regulatory decision based on animal carcinogenicity findings and federal law, rather than proof of human cancer caused by normal consumption.

Latest FDA Decision: August 2026 Objections Rejected

Following the January 2025 order, Micro-Tracers Inc. submitted objections challenging the FDA's decision and requested a public hearing.

On August 5, 2026, the FDA published its final response, rejecting the objections and denying the hearing requests.

The agency concluded that the objections did not provide a sufficient legal or scientific basis to modify the original decision.

The FDA also ended the administrative stay that had temporarily affected implementation of the revocation order.

The action confirmed that the original compliance deadlines would remain unchanged.

When Will Red Dye No. 3 Be Banned in Food and Medicine?

The FDA established separate compliance deadlines to give food and pharmaceutical manufacturers time to reformulate affected products.

The later pharmaceutical deadline provides additional time for manufacturers to adjust drug formulations and meet applicable regulatory requirements.

On July 14, 2025, the FDA encouraged food manufacturers to remove Red No. 3 before the 2027 deadline rather than waiting until the final compliance date.

As of November 2026, the federal transition period remains in effect, and some products may still legally contain the additive.

Which Foods May Contain Red Dye No. 3?

Red No. 3 has historically appeared in various brightly colored foods and confectionery products, including:

• Red and pink candies.
• Cake decorations and frostings.
• Cookies and certain baked goods.
• Frozen desserts.
• Some dietary supplements.
• Certain orally administered medications.

Not every red or pink product contains Red No. 3. Manufacturers may use other approved color additives or naturally derived coloring ingredients.

Consumers can identify the dye by checking ingredient labels for FD&C Red No. 3, Red 3 or erythrosine.

Red No. 3 should not be confused with Red No. 40, a different synthetic coloring with a separate regulatory history.

How Manufacturers Are Responding to the Ban

The FDA's decision requires affected manufacturers to reformulate their products before the relevant compliance deadlines.

Companies may replace Red No. 3 with other permitted colors or naturally derived alternatives, depending on their products' technical and labeling requirements.

In 2025, the FDA also announced a broader initiative encouraging manufacturers to eliminate several petroleum-based synthetic food dyes.

Major food companies have made voluntary commitments to reduce or remove certified synthetic colors from parts of their US product portfolios.

However, these voluntary commitments should not be confused with the specific legal prohibition on Red No. 3. Different additives remain subject to their own regulatory requirements and timelines.

How California Helped Renew Attention on Red No. 3

California enacted legislation in October 2023 prohibiting the manufacture, distribution and sale of foods containing Red No. 3 and several other specified additives, with restrictions taking effect in 2027.

The state law increased public attention on the longstanding differences between US federal additive authorizations and restrictions adopted elsewhere.

It also added pressure on manufacturers to consider reformulating products sold across multiple states.

Nevertheless, the FDA's 2025 decision was formally based on the Delaney Clause and its review of the 2022 petition, not on California's legislation alone.

Red Dye No. 3 Regulatory Timeline

• 1907: Erythrosine receives early federal authorization for certain uses.
• 1960: Congress establishes the relevant Delaney Clause prohibition for color additives.
• 1969: The FDA permanently authorizes Red No. 3 for food and ingested drugs.
• 1980s: Laboratory studies identify thyroid tumors in male rats exposed to high doses.
• February 1990: The FDA ends provisional authorization for cosmetics and externally applied drugs.
• October 2022: Consumer organizations petition the FDA to revoke food and ingested-drug authorizations.
• January 15, 2025: The FDA announces the revocation of Red No. 3's authorization.
• July 14, 2025: The agency encourages manufacturers to accelerate the phaseout.
• August 5, 2026: The FDA rejects objections and confirms the original compliance deadlines.
• January 15, 2027: The food and dietary supplement compliance deadline takes effect.
• January 18, 2028: The deadline takes effect for ingested medications.

What the Ban Means for Consumers

The Red No. 3 prohibition removes a synthetic coloring from the US food supply under a long-established legal standard concerning cancer findings in laboratory animals.

Consumers who prefer to avoid the additive can check ingredient labels during the transition period.

However, the FDA's decision does not establish that people who previously consumed products containing Red No. 3 have developed cancer or face a demonstrated cancer risk from normal exposure.

People taking prescribed medications should not stop treatment because of a coloring ingredient without first consulting a healthcare professional.

Conclusion

The FDA took nearly 35 years to revoke Red Dye No. 3's food authorization after restricting its cosmetic use in 1990. The delay reflected separate regulatory approvals, differing assessments of animal cancer findings and the lengthy process of reconsidering an established authorization.

The decisive action followed a 2022 petition invoking the Delaney Clause, which prohibits certain additives found to induce cancer in humans or animals.

Although Red No. 3 has not been shown to cause cancer in humans at typical exposure levels, the FDA concluded that the animal findings required revocation under federal law.

After rejecting objections in August 2026, the agency maintained its final phaseout deadlines of January 15, 2027, for foods and January 18, 2028, for ingested medications.