What is E121?
Complete guide to understanding E121 (Citrus Red 2) — a banned azo dye colour additive with carcinogenic potential
The Quick Answer
E121 (Citrus Red 2) is a synthetic red azo dye colour additive that is not approved in the EU and is banned or severely restricted worldwide.
What makes E121 exceptional: It’s a carcinogenic azo dye that was historically used in foods but is now essentially eliminated from human food use. The USA still approves it but ONLY for surface coating of oranges (not for consumption). The EU never approved it. It represents a clear example of how unsafe azo dyes have been phased out of food coloring.
E121 is one of the few colour additives with clear carcinogenic concern that remains partially approved anywhere (USA, external use only).
📌 Quick Facts
- Chemical Name: Citrus Red 2; Citrus Red No. 2
- Type: Synthetic azo dye; colour additive
- CAS Number: 6358-53-8
- Color: Orange-red to bright red
- EU Approval Status: NOT approved; banned
- USA Approval Status: Approved but ONLY for external orange coating (surface treatment)
- Main concern: Carcinogenic potential; azo dye structure
- Where found: Extremely rare; USA orange skin coating only
- Health risk: Potential carcinogen; allergic reactions; reproductive toxicity
- Consumer exposure: Minimal in USA (external coating); zero in EU
What Exactly Is It?
E121 is Citrus Red 2, a bright red synthetic azo dye — 100% chemically engineered, not found in nature.
Chemical structure: Complex aromatic azo compound with naphthalene-based structure
Appearance: Orange-red powder; highly soluble in water
Key properties:
– Colour: bright orange-red (cosmetic only)
– Synthetic: 100% chemically engineered
– Azo dye: contains azo bonds (-N=N-) known to have carcinogenic potential
– Petroleum-derived: made from crude oil derivatives
– Unstable in acidic conditions: degrades in stomach acid
– Lipophilic: fat-soluble; accumulates in fatty tissues
– Non-nutritive: no health benefit; purely cosmetic
Regulatory Status: EU vs. USA
E121 has dramatically different approval status across jurisdictions.
| Jurisdiction | Status | Permitted Use | Notes |
|---|---|---|---|
| European Union | NOT APPROVED | None | Never in approved list; zero use |
| United States | Approved (severely restricted) | External orange coating only | Surface treatment; not for internal consumption |
| Canada | NOT approved | None | Banned; not permitted |
| Australia/NZ | NOT approved | None | Banned; not permitted |
| Rest of world | Mostly banned/restricted | Very limited | Declining use globally |
Why EU Doesn’t Approve E121
EFSA’s reasoning (implicit; E121 never submitted for approval):
– Carcinogenic potential; azo dye structure suspect
– No adequate safety data
– Better alternatives available
– No justification for use given cancer concern
– Precautionary principle: avoid substances with cancer risk
Why USA Still Approves (Externally)
FDA’s reasoning (historically; still approved):
– Approved for cosmetic effect on orange appearance
– Restricted to surface treatment only (external coating)
– Expected minimal internal exposure (consumers wash oranges)
– Risk acceptable under strict restrictions
– Regulatory inertia: approved substances rarely delisted
– Batch certification required; safety monitoring continues
The Carcinogenicity Concern
E121’s primary safety issue is its carcinogenic potential.
Evidence of Cancer Risk
– Azo dye structure: Contains azo bonds known to be carcinogenic
– Aromatic amines: Breakdown products may be carcinogenic
– Animal studies: Suggests cancer risk in chronic exposure
– Genotoxicity: Possible genetic damage
– Classification: Suspect carcinogen based on chemical structure
Allergic Reactions
– Urticaria (skin rashes) documented
– Allergic reactions in sensitive individuals
– More common than with modern approved colours
– Particularly in children; asthma aggravation reported
Reproductive/Developmental Concerns
– Animal studies suggest reproductive toxicity
– Potential harm to fetus (developmental toxicity)
– May impair fertility
– Data gaps remain; full risk not completely characterized
Where Is E121 Found Today?
E121 is extremely rare in modern food supply.
Current use (2025):
– USA only: Surface coating of mature oranges and tangerines
– Minimal use: FDA approval exists but rarely used today
– EU: Zero; never found in approved products
– Rest of world: Essentially eliminated
Historic uses (now banned):
– Red-coloured beverages and cocktails
– Food colourings in sweets, baked goods
– Processed meats (red colouring)
– All now replaced by safer alternatives
If you encounter E121: It’s almost certainly not on a modern EU food label (not permitted). If found on a USA orange, it’s surface treatment (don’t consume peel). If found elsewhere, it indicates mislabeling or product from early 2000s or earlier.
E121 vs. E123 (Amaranth): The Confusion
E121 and E123 are often confused — both are red azo dyes with carcinogenic concerns.
| Aspect | E121 (Citrus Red 2) | E123 (Amaranth) |
|---|---|---|
| Chemical class | Azo dye | Azo dye |
| Color | Orange-red | Deep red/purple |
| EU approval | NOT approved | Limited approval (some uses) |
| USA status | Approved (external oranges only) | Banned since 1976 |
| Current use | Minimal (orange coating) | Limited (cherries, aperitifs UK) |
| Safety status | High concern (carcinogenic) | Moderate concern (restricted) |
The Bottom Line
E121 (Citrus Red 2) is a banned or severely restricted synthetic azo dye with carcinogenic potential.
What you should know:
- It’s not approved in EU: Never appears on EU food labels
- It’s barely used in USA: Only external orange coating; not for consumption
- It has carcinogenic concern: Azo dye structure with documented cancer risk
- It causes allergic reactions: More problematic than modern approved colours
- It’s a historical additive: Essentially phased out globally
- It’s one of the safest to avoid: Clear reasons for restriction
- No health benefit: Purely cosmetic; replaceable with safer alternatives