Is iron oxide red (ci 77491) safe in food and drink?

Under the app's default Cautious lens, iron oxide red (ci 77491) in food and drink rates Swap: the app would put this near the top of your swap plan. 2 sourced concerns count (restricted, consensus tier; metabolic, emerging tier). This is research with sources, not medical advice.

What do the Clean, Low, Watch and Swap levels mean?

They are cut from a continuous concern level the app computes from the sourced claims that the chosen evidence lens shows: each claim counts its concern class, tier weight, confidence and dose relevance, combined worst-first with a decay so one serious finding outweighs many small ones, then scaled by how much of the substance reaches you in this use. Clean is below 0.35, Low below 1.1, Watch below 2.0 and Swap above that, on a 0 to 3 scale.

Is Iron Oxide Red (ci 77491) safe on skin (left on)?

Cosmetics2 uses researched5 sourced claims

Where it turns up: red pigment, cosmetic colorant, common. Detox My Life researched iron oxide red (ci 77491) under 2 different uses, because the same substance means something different in each. Every claim below carries its evidence tier, how sure the research is that it applies here, and the sources it cites. The level is computed by the app's own deterministic engine, so the page says exactly what the app would.

Level by use and lens

Use	Mainstream	Cautious (default)	Based	Concerns · favour · fringe
On skin, left on	Swap	Swap	Swap	3 · 0
Eaten or drunk	Swap	Swap	Swap	2 · 0

Mainstream shows consensus claims only; Cautious adds emerging research; Based adds fringe claims, labelled as such. The last column counts, under Cautious, the sourced concerns, the findings in its favour and the fringe claims Based would add.

Safer swaps: the app's swap catalog has no entry tied to this ingredient yet. When you scan a product that contains it, the app suggests cleaner alternative types for that product; the swap categories list what the catalog covers today.

On skin, left on Swap

Under the default Cautious lens iron oxide red (ci 77491) on skin (left on) rates Swap: the app would put this near the top of your swap plan. Mainstream (consensus only) rates it Swap; Based (adds the fringe) rates it Swap. Researched 2026-09-03.

Sourced concerns (3)

ConsensusRestrictedconfidence 100%

Cosmetic-grade iron oxide red (CI 77491) is restricted by regulatory bodies, such as the FDA and EU, to ensure low levels of heavy metal impurities.

Why here: Naturally occurring iron oxides can contain heavy metals, but those used in dermal leave-on cosmetics are synthetically produced and purified to meet strict regulatory specifications for safe skin application.
What would have to be true: Dermal leave-on application of cosmetic products containing CI 77491 that adheres to regulatory purity standards for heavy metal content.
The other side: Cosmetic-grade iron oxides are synthetically produced and rigorously tested to be free from harmful levels of heavy metals, making them safe for cosmetic use.

Sources the engine cites:

Regulatory Status of Color Additives - hfpappexternal.fda. — fda.gov (2026) · regulator or public body
Quality and safety investigation of commonly used topical cosmetic preparations - PMC — nih.gov · regulator or public body
Iron Oxides - Cosmetics Info — cosmeticsinfo.org · review
1 web article (tiiips.com), linked in the app.
5 community or commercial pages, not counted here.

ConsensusIrritant · allergenconfidence 100%

While generally considered non-irritating and non-allergenic, iron oxide red (CI 77491) can, in rare instances, cause allergic reactions in sensitive individuals.

Why here: Dermal leave-on products remain on the skin for extended periods, allowing for prolonged contact where a rare individual sensitivity could manifest.
What would have to be true: Dermal leave-on application of cosmetic products containing CI 77491.
The other side: Iron oxides are widely recognized as non-irritating, non-comedogenic, and suitable for sensitive skin types, with a low hazard rating on the Environmental Working Group (EWG) Skin Deep database.

Sources the engine cites (no regulator, review or study among them):

1 web article (skintypesolutions.com), linked in the app.
4 community or commercial pages, not counted here.

EmergingMetabolicconfidence 100%

Studies indicate that iron oxide nanoparticles, when present in certain semi-solid formulations, can penetrate the stratum corneum and occasionally reach the viable epidermis in ex vivo human skin, though they do not permeate through the skin.

Why here: Dermal leave-on products containing iron oxide nanoparticles would allow for prolonged skin contact, potentially leading to accumulation in the upper skin layers.
What would have to be true: Dermal leave-on application of cosmetic products specifically formulated with iron oxide nanoparticles.
The other side: Many cosmetic manufacturers intentionally use non-nanoparticle forms of iron oxides to avoid potential skin penetration. Additionally, studies show that bare iron oxide nanoparticles applied to skin are largely removed by washing.

Sources the engine cites:

Impact of semi-solid formulations on skin penetration of iron oxide nanoparticles - PubMed — nih.gov (2017) · regulator or public body
1 community or commercial page, not counted here.

Eaten or drunk Swap

Under the default Cautious lens iron oxide red (ci 77491) in food and drink rates Swap: the app would put this near the top of your swap plan. Mainstream (consensus only) rates it Swap; Based (adds the fringe) rates it Swap. Researched 2026-09-03.

Sourced concerns (2)

ConsensusRestrictedconfidence 100%

Synthetic iron oxide, including red iron oxide (CI 77491 or E172), is restricted as a food colorant to specific maximum levels and purity specifications by regulatory bodies in various regions, including the EU and USA.

Why here: It is approved and used as a coloring agent in various food products, and its use is subject to regulatory limits to ensure safety.
What would have to be true: Ingestion as a food additive at levels consistent with Good Manufacturing Practice (GMP) and within established Acceptable Daily Intake (ADI) or maximum permitted levels (e.g., 0.5 mg/kg body weight per day in the EU, or up to 5 mg elemental iron per day in dietary supplements in the US).

Sources the engine cites:

Listing of Color Additives Exempt From Certification; Synthetic Iron Oxide — federalregister.gov (2015) · regulator or public body

EmergingMetabolicconfidence 70%

Excessive intake of iron, including from sources like iron oxides, can potentially lead to conditions such as hemochromatosis or minor gastrointestinal irritation.

Why here: Iron oxide red contains iron, and while poorly absorbed as a colorant, extremely high doses could theoretically contribute to overall iron load.
What would have to be true: Ingestion of iron oxide red (CI 77491) in quantities far exceeding typical dietary doses or regulatory limits for food additives.
The other side: When used as a food additive within regulated limits, iron oxides are poorly absorbed in the gastrointestinal tract and are considered physiologically inert, meaning they do not contribute significant bioavailable iron to the body.

Sources the engine cites (no regulator, review or study among them):

1 web article (proe.info), linked in the app.

Not researched here

The engine has no dossier for iron oxide red (ci 77491) when cooked with heat, in cold food, as a finishing ingredient, in heated food packaging or other uses. The app researches an ingredient for the use it infers from your product, so a scan fills these in; this page only shows what has already been researched and source-verified.

This is research, not medical advice. Detox My Life shows sourced claims sorted by evidence tier. It does not diagnose, treat, or tell you to start or stop anything. Talk to a qualified professional about your health.

Scan your own. The app reads any product label with your camera, works out how you are about to use it, and researches every ingredient for that use with live sources. Every scan adds to a Detox Score for your home, where 50 is a typical home in your region, and a plan of next swaps.

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